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Article

In Situ Growth of Magnesium Oxide Nanoparticles on ITO Electrodes as Electrocatalysts for Detecting Bisphenol A in Thermal Paper

by
Abdullah Akhdhar
and
Waleed A. El-Said
*
Department of Chemistry, College of Science, University of Jeddah, P.O. Box 80327, Jeddah 21589, Saudi Arabia
*
Author to whom correspondence should be addressed.
Catalysts 2025, 15(9), 901; https://doi.org/10.3390/catal15090901
Submission received: 6 August 2025 / Revised: 12 September 2025 / Accepted: 16 September 2025 / Published: 18 September 2025
(This article belongs to the Special Issue Electrochemical and Electrocatalysis with Porous Materials)
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Abstract

Here, MgO nanoparticles/ITO electrodes were fabricated through the hydrothermal method and utilized for monitoring bisphenol A (BPA). Various characterization analyses were utilized, including SEM, XRD, Raman, and FTIR techniques, to investigate the modified electrode’s morphology and structure. The modified sensor shows an LOD of 1.13 nmol L−1 over a linear range of 50 nmol L−1–10 µmol L−1. Here, fourteen thermal paper receipt samples were randomly obtained from the local markets in Jeddah, KSA. Then, BPS was extracted and analyzed using electrochemical methods. The results indicated that (i) forty percent of the samples investigated showed high BPA levels, and (ii) twenty-seven percent of the samples showed low BPA levels, while (iii) twenty-three percent of the samples showed very low or no BPA. The significance of this study is related to its health effects, recent legal restrictions by the EU, and frequent exposure to BPA sources. Our future work will focus on achieving quantitative analysis of BPA in thermal paper samples. Furthermore, we recommend that wearing gloves be mandatory, especially for people with regular work-related exposure to thermal paper.

Graphical Abstract

1. Introduction

Bisphenol A (BPA) (2,2-bis(4-hydroxyphenyl)propane) is a synthetic xenoestrogen. The thermal stability and cost-effectiveness of BPA make it one of the widely used chemicals in various industrial fields, e.g., the polycarbonate plastic production for food and beverage containers, epoxy resin linings, dental sealants, PVC food packaging, stretch films, paints and coatings, and thermal papers (i.e., receipts) [1,2]. BPA could interfere with the hormonal system. BPA could be present in either conjugated or unconjugated forms. The unconjugated form can bind to estrogen receptors. Thus, it is more hazardous, especially since it could enter the body through dermal contact and inhalation [3]. BPA exposure for prolonged periods at high concentrations can lead to adverse health effects, primarily affecting the reproductive and hormonal systems, as well as increasing the risk of cardiovascular diseases, developmental abnormalities, and insulin resistance [4,5]. Furthermore, BPA is an environmental pollutant in surface waters and sediments [6]. According to the final report of European Food Safety Authority (EFSA) that was released in April 2023, the safe level of exposure to BPA is 0.2 nanograms per kg of bodyweight per day [7]. Meanwhile, the U.S. FDA reported that the safe level of exposure to BPA is 200 nanograms per kg of bodyweight per day [8].
Thermal paper (e.g., receipts) is an example of the nonfood sources of exposure to BPA, in which BPA is present in its monomeric form [9,10]. Thus, BPA is readily transdermally absorbed through the skin, especially wet or greasy skin [11,12]. Retail workers and cashiers have been found to have elevated levels of urinary BPA [11,13]. BPA can cross the placenta [14] and is toxic during early mammalian development, including humans [15]. Prenatal exposure of human infants to BPA has been associated with behavioral anomalies [16,17]. Analyses of thermal receipt papers globally confirmed the presence of varying BPA concentrations; some of them showed concentrations over the EU limit (<0.02% by weight) [18].
Molina-Molina’s group [19] explored BPA concentrations in thermal papers from Brazil, France, and Spain. Their results revealed that 95.3%, 90.9%, and 51.1% of receipts from Spain, Brazil, and France, respectively, contain BPA at concentrations up to 20.3 mg/g [19]. Frankowski and his group collected 220 samples of thermal paper from several countries. They evaluated the presence of BPA [11], which showed that 22% of the samples investigated contained BPA levels higher than the EU limit. Wong et al. reported that 13 thermal paper receipt samples out of 30 samples collected from British Columbia, Canada, contain high levels of BPA [20]. Furthermore, all collected thermal paper samples in China exceed the BPA limit [21]. In Spain, several studies investigated the presence of BPA in thermal printing paper samples [22,23]. The findings showed that some samples contain varied BPA concentrations. Also, samples collected from Belgium showed the presence of high BPA levels [24]. Also, the BPA level in thermal paper receipts collected from Italian markets showed that 88% of the samples contain a high level of BPA [25].
Besides the effects of BPA mentioned above, BPA exposure could disrupt hormone synthesis, alter hormone levels in the blood, cause the feminization of male fetuses, reduce testosterone levels, and lead to irregular menstrual cycles [26]. Additionally, BPA is linked to other health issues such as obesity, diabetes, cardiovascular and autoimmune diseases, brain disorders, and prostate and breast cancer [27]. Therefore, it is important to monitor BPA levels in consumer goods frequently. Several analytical techniques have been reported for BPA detection, including chemiluminescence, liquid chromatography/mass spectrometry, gas chromatography/mass spectrometry, enzyme-linked immunosorbent assay, and fluorescence [28,29,30,31,32,33]. Although these traditional methods offer high sensitivity and selectivity, they are expensive, time-consuming, and require trained personnel. Therefore, there is a need to develop simple and sensitive sensors for the rapid and effective quantitative determination of BPA.
Consequently, electrochemical techniques offer several advantages, including simplicity, low cost, reliability, and high sensitivity compared to other analytical techniques. Therefore, the electrochemical methods (cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), and square wave voltammetry (SWV)) have been employed for BPA detection [34,35,36,37,38,39,40,41,42,43,44,45]. Recently, several electrochemical sensors have become valuable for BPA detection due to their high sensitivity, cost-effectiveness, ease of manipulation, fast response, and portability [46,47]. Several nanomaterials, including carbon nanostructures, metal nitride nanoparticles, noble metal nanoparticles, polymers, ionic liquids, metal oxide nanoparticles, nanocomposites, and others, have been used to improve the efficiency of the electrochemical sensors [48,49,50,51,52,53,54,55,56]. Amid these materials, metal oxide nanostructures such as TiO2, MgO, Fe3O4, ZnO, and CoFe2O4 NPs have wide applications in several fields, including modified electrodes, optical measuring devices, and electronics [57,58,59,60]. Furthermore, noble metal nanostructures (e.g., Ag NPs, Au NPs, etc.) modified electrodes were widely used for sensing several drugs and hazardous species, which showed high sensitivity and selectivity [61,62,63].
Magnesium oxide nanoparticles (MgO NPs) possess noteworthy properties such as a high surface area, excellent thermal stability, high melting (2850 °C) and boiling points (3600 °C), biocompatibility, and cost-effectiveness [64]. MgO NPs are among the wide bandgap semiconductors with potential applications in various fields [65], including photoluminescence, adsorption, templates, catalysis, electrochemical sensors, wastewater remediation, electronics, and photovoltaic applications [66,67,68]. Furthermore, MgO NPs are used as additives in refractory, paint, and superconducting products, transparent ceramics, bactericides, and adsorbents [69]. Several synthesis methods are applied for the preparation of MgO NPs, such as hydro/solvothermal, electrochemical, precipitation, chemical vapor deposition, carbothermic reduction, electro-spinning, template, laser ablation/deposition, sol–gel, pyrolysis, microwave, sputtering, and sonochemical methods [70,71,72,73,74,75,76]. The properties of the obtained MgO NPs are strongly affected by the synthetic method [77,78]. The MgO NPs play a pivotal role in the sensor field due to their eco-friendly, non-toxic, and cost-effective properties [79,80,81]. The hydrothermal synthesis method is one of the standout synthesis methods due to its advantages, including being eco-friendly, cost-effective, simple, and reliable while producing highly homogeneous, highly crystalline, and excellent chemically stable nanostructures [82].
This research aims to investigate the presence of BPA in thermal paper receipts collected from local supermarkets, pharmacies, banks, and restaurants in Jeddah, Saudi Arabia. Here, ITO electrodes were decorated with MgO NPs through the hydrothermal technique. The modified electrodes were properly characterized using SEM, XRD, Raman spectroscopy, CV, and FTIR techniques. CV, LSV, and DPV electrochemical techniques were used to monitor BPA in the thermal paper receipts via MgO NPs-modified electrodes. The modified sensor shows an LOD of 17.5 nmol L−1 over a linear range of 100 nmol L−1–15 µmol L−1. Fifteen thermal paper receipts were collected from local supermarkets in Jeddah, and the BPA presence was investigated. The results confirmed that 10 out of 15 samples contained BPA. The main analytical parameters were studied and optimized. This study provides semi-quantitative data on BPA levels in thermal paper receipts, and it contributes to environmental and health protection by sharing knowledge about BPA exposure from thermal paper receipts.

2. Results and Discussion

2.1. MgO NPs/ITO Electrodes’ Characterization

2.1.1. SEM Analysis

The morphology of the MgO NPs/ITO surface was studied using the SEM technique. Figure 1a demonstrates the SEM image of MgO NPs/ITO, which indicates the formation of a layer of MgO over the ITO substrate, in addition to the formation of irregular cuboid structures. The SEM image was analyzed by using ImageJ software (ij154) (Figure S1); the results indicated that the formed cuboid has an average width of 550 nm and an average length of 839 nm.

2.1.2. FTIR Analysis

The chemical composition and the functional groups of MgO NPs were examined based on the FTIR spectroscopy (400–4000 cm−1), as shown in Figure 1b. The FTIR spectrum demonstrated a band at 3427 cm−1 corresponding to the hydroxyl groups (O–H) stretching mode, which confirmed the presence of the adsorbed moisture on the MgO surface, as well as the Mg–OH bond during the sample synthesis [83,84]. Also, the band observed at 524 cm−1 is ascribed to the Mg–O symmetric vibration band [85,86,87].

2.1.3. XRD Analysis

Figure 1c shows the XRD analysis of the MgO/ITO electrode performed using CuKα radiation in the 2θ range from 30 to 80°. The XRD pattern demonstrated characteristic peaks at 2θ = 36.94° (111), 42.94° (200), 62.44° (220), 74.8° (311), and 78.76° [84,85]. The results confirm the synthesis of a pure cubic; also, the presence of intense and sharp peaks confirms the existence of crystalline nanostructures [84,85].

2.1.4. Raman Spectroscopy Analysis

Raman spectroscopy was employed to investigate the phase formation and structure of the fabricated MgO NPs/ITO. Figure 1d represents the Raman spectrum of MgO NPs/ITO within the Raman shift from 200 to 1600 cm−1. The results show a set of Raman peaks at 281 cm−1, 485 cm−1, 812 cm−1, 967 cm−1, and 1030 cm−1 corresponding to the cubic structure of MgO NPs [83,88]. Furthermore, the Raman peaks at 231 and 580 cm−1 are characteristic of ITO [89].

2.2. Electrochemical Performance of MgO/ITO Electrodes Towards BPA

Figure 2a (black curve) shows the CV response of 5 mmol L−1 of [Fe(CN)6]3−/4− on a bare ITO electrode, displaying the characteristic CV response of the redox couple [Fe(CN)6]3−/4− with an anodic peak at 0.44 V and a cathodic peak at 0.11 V. When ITO is modified with MgO NPs, the CV response of the redox couple shows typical behavior with a notable increase in both sensitivity and reversibility, as illustrated by the blue curve in Figure 2a (blue curve). The results indicate that the anodic peak shifts to a less positive potential (0.35 V), and the cathodic peak shifts to a more positive potential (0.18 V). Consequently, the potential difference between the redox peaks decreases compared to the bare ITO electrode, confirming that the process becomes more reversible. Additionally, the redox current peaks shift to a higher current, approximately 48% greater than those observed with the bare ITO electrode, which confirms the enhancement in sensitivity due to the decoration of the bare ITO with MgO NPs.
Figure 2b (black curve) demonstrates the CV response of 2 μmol L−1 of BPA at a bare ITO electrode that shows a background response, and no redox peaks could be observed. Furthermore, Figure 2b (red curve) shows the CV of the MgO NPs/ITO electrode in PBS, which demonstrates a background response without any redox peak. The CV response of 2 μmol L−1 of BPA at MgO NPs/ITO electrode is represented in Figure 2c. This result shows an oxidation potential peak at about 0.62 V that confirms the capability of the MgO NPs/ITO electrode to monitor BPA. The electrochemical oxidation mechanism of BPA is shown in Scheme 1a.
The media pH plays a crucial role in the performance of the designed BPA sensor. The pH effect on monitoring 2 µmol L−1 BPA was investigated by recording the CVs voltammograms of BPA dissolved in PBS with different pH values (pH from 4.1 to 10.1), as shown in Figure 3a. The results indicate that the intensity of the oxidation current peak depends on the media pH. To study the effect of pH on the intensity of the oxidation current peak, the relationship between the oxidation current peak and pH is represented in Figure 3b. The results indicate that the peak current increases as the pH rises from 4 to 7 [55]. Conversely, as the pH increases from 7 to 10, the peak current decreases. Therefore, a pH of 7 was chosen as the optimal pH value for the developed sensor. Furthermore, the oxidation potential peak was shifted to the positive direction with increases in pH value [90].
The interference effect of several species, including 0.1 mmol L−1 of glucose (Glu), Pb(II), ascorbic acid (AA), uric acid (UA), and Cd(II), was studied. See Figure 3c. The response of 10 μmol L−1 BPA in compared with the response to other interferences, the sensor showed a negligible signal response to the above-mentioned interferents. Therefore, this sensor showed excellent anti-interference performance for BPA detection.
The sensitivity of the MgO NPs/ITO electrode toward BPA was investigated by monitoring different concentrations of BPA. Figure 4a shows the LSV voltammograms of 100 nmol L−1–15 μmol L−1 of BPA, which indicates the rise of the current peak with increasing BPA concentration. The relationship between the BPA concentrations and the corresponding current is represented in Figure 4b, which shows a linear curve over the wide range from 100 nmol L−1 to 15 μmol L−1 with an R2 = 0.994. The LOD of the modified sensor is 17.5 nmol L−1.

2.3. Electrochemical Monitoring of BPA in Various Thermal Paper Samples

To conduct a quantitative analysis of the BPA, the DPV voltammograms of different concentrations of BPA (50 nmol L−1–10 μmol L−1) were recorded, as shown in Figure 4c. The results showed that the intensity of the oxidation current peak increased with the increase in the BPA concentration. Figure 4d represents the relationship between the intensity of the current peaks and their corresponding BPA concentrations, which demonstrates a linear curve that follows Equation (1), with R2 of 0.993. The LOD based on DPV results is 1.13 nmol L−1. The sensitivity of the developed BPA sensor was compared with the previously reported sensors (Table 1). The results indicated that this sensor is among the highly sensitive BPA sensors.
i(μA) = 0.30694 + 0.06758[BPA] (μmol L−1)
Fifteen samples were collected from the domestic markets in Jeddah, and the presence of BPA in these samples was evaluated based on the DPV technique. Then, the DPV voltammograms of the 15 thermal paper extracts are demonstrated in Figure 5. The BPA concentration was calculated based on Equation (1). The samples indicated that they contain different BPA levels. The BPA found in the thermal paper samples is tabulated in Table 2. The results could be classified into three groups: (i) four samples showed strong oxidation peaks indicating that 26.66% of the samples contain a high level of BPA, (ii) seven samples demonstrated oxidation peaks with low intensities, which confirmed that 46.66% of the samples contain a medium level of BPA, and (iii) four samples demonstrated no oxidation peaks, which confirmed that 26.66% of the samples did not contain BPA. These results show the capability to evaluate BPA levels in the thermal paper samples.
The significance of this study is related to its health effects, recent legal restrictions by the EU, and frequent exposure to BPA sources. Furthermore, we recommend that wearing gloves be mandatory, mainly for people with frequent occupational exposure to thermal paper.

3. Materials and Methods

3.1. Materials

Magnesium nitrate Mg(NO3)2·6H2O, bisphenol A, indium tin oxide (ITO) coated glass substrates, sodium hydroxide, phosphate-buffered saline (PBS), and cetyl trimethyl ammonium bromide (CTAB) were obtained from Sigma-Aldrich (St. Louis, MO, USA).

3.2. In Situ Fabrication of MgO/ITO Modified Electrodes

Firstly, ITO substrates were cleaned by immersing them in an ammonium peroxide mixture (H2O2, NH3, and H2O in a 1:1:5 ratio) for 30 min at room temperature. Next, the substrates were rinsed with water and ethanol and then dried using N2 gas. MgO NPs were grown on the ITO surface as follows: 1 g of Mg(NO3)2·6H2O and 0.1 g of CTAB were dissolved in 75 mL of distilled water. Then, 0.01 mol L−1 NaOH solution was added dropwise to the Mg(NO3)2 solution until the pH reached approximately 10. Notably, a white precipitate formed at this pH, with continuous stirring for 1 h at room temperature. ITO substrates were placed inside a Teflon-lined vessel, and the Mg(II) solution was then added over the substrates. The Teflon-lined vessel was sealed inside a stainless-steel autoclave and heated at 180 °C for 5 h [93]. The modified ITO substrates were washed with distilled water and ethanol and then dried in an oven at 80 °C. The fabrication of the modified electrodes is represented in Scheme 1b.

3.3. Sample Collection

Fifteen thermal paper receipt samples were randomly obtained from various places in Jeddah, KSA, including supermarkets (n = 3), restaurants and cafes (n = 6), automatic teller machines (n = 2), and centers/pharmacies (n = 4).

3.4. Sample Extractions

One g of each thermal paper sample was cut into small pieces and extracted into 25 mL of distilled water for 60 min at room temperature [94]. The supernatants were collected, and their pH was adjusted. Electrochemical techniques, including CV, LSV, and DPV, were used to evaluate the BPA.

3.5. Electrochemical Measurements

Electrochemical measurements were carried out using a custom-built three-electrode cell consisting of Pt, Ag/AgCl, and modified ITO electrodes, serving as the counter, reference, and working electrodes, respectively. PBS was employed as the electrolyte in various electrochemical techniques, including CV, LSV, and DPV. CV voltammograms were recorded at a scan rate of 100 mV/s.

3.6. Instrumentation

The electrochemical experiments were performed using the Autolab workstation (PGSTAT101) (Metrohm Autolab, Herisau, Switzerland). The FTIR spectrum was recorded with a Nicolet Nexus 640-MSA spectrometer (4000–400 cm−1 range, 4 cm−1 resolution, 32 scans) using the KBr pellet method (Thermo Fisher Scientific, Gaithersburg, MD, USA). Also, the X-ray pattern was conducted on a Philips PW 3710/31 diffractometer with Cu Kα radiation (λ = 1.5406 Å, 40 kV, 30 mA) (Philips, Amsterdam, The Netherlands). Furthermore, the MgO NPs/ITO electrode morphology was analyzed with scanning electron microscopy (SEM) using a JEOL instrument (JSM-5400 LV, Tokyo, Japan). Also, the Raman spectrum was studied using Bruker Senterra Raman microscope (Bruker Optics Inc., Ettlingen, Germany). The sample was excited with a 785 nm wavelength laser (50 mW power) for an acquisition time of 10 s.

4. Conclusions

A simple, sensitive, and cost-effective electrochemical sensor based on MgO NPs-modified ITO electrode was developed for BPA monitoring. The MgO NPs-modified-ITO electrodes were prepared through a simple hydrothermal process in which MgO NPs were prepared and deposited in situ onto the ITO surfaces. The fabrication process of the proposed sensor is simple, eco-friendly, and low-cost, and it is a one-step process. The MgO NPs-modified ITO electrodes show excellent electrocatalytic activity towards BPA with a low LOD over a wide range of concentrations from 100 nmol L−1 to 15 μmol L−1. The MgO NPs-modified-ITO electrode was applied for the monitoring of BPA in several paper samples collected from the local markets. The results confirmed the capability of monitoring BPA levels in the thermal paper samples; thus, this work presented an easy, fast, and sensitive tool for the in-field detection of BPA.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/catal15090901/s1, Figure S1: ImageJ software analysis of the distribution of the (a) width and (b) length.

Author Contributions

Conceptualization, A.A. and W.A.E.-S.; methodology, W.A.E.-S.; software, W.A.E.-S.; validation, A.A. and W.A.E.-S.; formal analysis, A.A. and W.A.E.-S.; investigation, W.A.E.-S.; writing—original draft preparation, A.A. and W.A.E.-S.; writing—review and editing, funding acquisition, A.A. All authors have read and agreed to the published version of the manuscript.

Funding

This work was funded by the University of Jeddah, Jeddah, Saudi Arabia, under grant No. (UJ-24-DR-454-1).

Data Availability Statement

The authors confirm that the data supporting the findings of this study are available within the article and its Supplementary Materials.

Acknowledgments

The authors thank the University of Jeddah for its technical and financial support.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. American Chemistry Council (ACC). Industrial & Business: Facts About BPA. 2022. Available online: https://www.factsaboutbpa.org/benefits-applications/industrial-business/ (accessed on 5 August 2025).
  2. Yoshiyuki, T.; Ayako, S.; Takako, S.; Tatsuya, T.; Kazuhisa, S. Why does a color-developing phenomenon occur on thermal paper comprising of a fluoran dye and a color developer molecule? Bull. Chem. Soc. Jpn. 2002, 75, 2225–2231. [Google Scholar] [CrossRef]
  3. Bernier, M.R.; Vandenberg, L.N. Handling of thermal paper: Implications for dermal exposure to Bisphenol A and its alternatives. PLoS ONE 2017, 12, e0178449. [Google Scholar] [CrossRef] [PubMed]
  4. Toxic Impressions: BPA in Thermal Paper, a New Report by Toxics Link. IPEN. 2017. Available online: https://ipen.org/news/toxic-impressions-bpa-thermal-paper-new-report-toxics-link (accessed on 5 August 2025).
  5. Vom Saal, F.S.; Vandenberg, L.N. Update on the Health Effects of Bisphenol A: Overwhelming Evidence of Harm. Endocrinology 2021, 162, bqaa171. [Google Scholar] [CrossRef]
  6. Mendum, T.; Stoler, E.; Van Benschoten, H.; Warner, J.C. Concentration of bisphenol A in thermal paper. Green Chem. Lett. Rev. 2011, 4, 81–86. [Google Scholar] [CrossRef]
  7. EFSA Press Release. April 2023. Available online: https://www.efsa.europa.eu/en/news/bisphenol-food-health-risk (accessed on 5 August 2025).
  8. Available online: https://www.ehn.org/how-much-bpa-in-our-bodies-2641524955.html (accessed on 5 August 2025).
  9. Taylor, J.A.; vom Saal, F.S.; Welshons, W.V.; Drury, B.; Rottinghaus, G.; Hunt, P.A.; Toutain, P.L.; Laffont, C.M.; VandeVoort, C.A. Similarity of bisphenol A pharmacokinetics in rhesus monkeys and mice: Relevance for human exposure. Environ. Health Perspect. 2011, 119, 422–430. [Google Scholar] [CrossRef]
  10. El-Said, W.A.; Abdelshakour, M.; Choi, J.-H.; Choi, J.-W. Application of conducting polymer nanostructures to electrochemical biosensors. Molecules 2020, 25, 307. [Google Scholar] [CrossRef]
  11. Frankowski, R.; Zgoła-Grzeskowiak, A.; Grzeskowiak, T.; Sojka, K. The presence of bisphenol A in the thermal paper in the face of changing European regulations—A comparative global research. Environ. Pollut. 2020, 265, 114879. [Google Scholar] [CrossRef]
  12. Reale, E.; Vernez, D.; Hopf, N.B. Skin Absorption of Bisphenol A and Its Alternatives in Thermal Paper. Ann. Work. Expo. Health 2021, 65, 206–218. [Google Scholar] [CrossRef] [PubMed]
  13. Lunder, S.; Andrews, D.; Houlihan, J. Synthetic Estrogen BPA Coats Cash Register Receipts. 2010. Available online: http://www.ewg.org/bpa-in-store-receipts (accessed on 13 May 2011).
  14. Balakrishnan, B.; Henare, K.; Thorstensen, E.B.; Ponnampalam, A.P.; Mitchell, M.D. Transfer of bisphenol A across the human placenta. Am. J. Obs. Gynecol. 2010, 202, 393.e1–393.e7. [Google Scholar] [CrossRef]
  15. vom Saal, F.S.; Hughes, C. An extensive new literature concerning low-dose effects of bisphenol A shows the need for a new risk assessment. Environ. Health Perspect. 2005, 113, 926–933. [Google Scholar] [CrossRef]
  16. Landrigan, P.J.; Goldman, L.R. Children’s vulnerability to toxic chemicals: A challenge and opportunity to strengthen health and environmental policy. Health Aff. 2011, 30, 842–850. [Google Scholar] [CrossRef]
  17. Schwartz, A.W.; Landrigan, P.J. Bisphenol A in thermal paper receipts: An opportunity for evidence-based prevention. Environ. Health Perspect. 2012, 120, A14–A15. [Google Scholar] [CrossRef]
  18. European Union (EU). Commission regulation 2016/2235 of 12 December 2016 amending annex XVII to regulation (EC) No 1907/2006 of the European parliament and of the council concerning the registration, evaluation, authorisation and restriction of chemicals (REACH) as regards bisphenol A. Off. J. Eur. Union 2016, L337, 3–5. [Google Scholar]
  19. Molina-Molina, J.M.; Jiménez-Díaz, I.; Fernández, M.F.; Rodriguez-Carrillo, A.; Peinado, F.M.; Mustieles, V.; Barouki, R.; Piccoli, C.; Olea, N.; Freire, C. Determination of bisphenol A and bisphenol S concentrations and assessment of estrogen- and anti-androgen-like activities in thermal paper receipts from Brazil, France, and Spain. Environ. Res. 2019, 170, 406–415. [Google Scholar] [CrossRef] [PubMed]
  20. Wong, R.; Karakilic, V.; Soulsbury, K. Bisphenol A (BPA) in Thermal Paper Used for Receipts. BCIT Environ. Public. Health 2016, 205, 1–10. [Google Scholar] [CrossRef]
  21. Zhang, J.; Wen, C.; Li, Q.; Meteku, B.E.; Zhao, R.; Cui, B.; Li, X.; Zeng, J. Electro-enhanced solid-phase microextraction of bisphenol A from thermal papers using a three-dimensional graphene coated fiber. J. Chromatogr. A 2019, 1585, 27–33. [Google Scholar] [CrossRef]
  22. Castro, G.; Rodrı’guez, I.; Ramil, M.; Cela, R. Direct analysis in real time accurate mass spectrometry determination of bisphenol A in thermal printing paper. Talanta 2019, 205, 120086. [Google Scholar] [CrossRef]
  23. Yalcin, M.S.; Gecgel, C.; Battal, D. Determination of Bisphenol A in thermal paper receipts. JOTCSA 2016, 3, 167–174. [Google Scholar] [CrossRef][Green Version]
  24. Geens, T.; Goeyens, L.; Kannan, K.; Neels, H.; Covaci, A. Levels of bisphenol-A in thermal paper receipts from Belgium and estimation of human exposure. Sci. Total Environ. 2012, 435–436, 30–33. [Google Scholar] [CrossRef] [PubMed]
  25. Russo, G.; Barbato, F.; Grumetto, L. Monitoring of bisphenol A and bisphenol S in thermal paper receipts from the Italian market and estimated transdermal human intake: A pilot study. Sci. Total Environ. 2017, 599–600, 68–75. [Google Scholar] [CrossRef]
  26. Manfo, F.P.; Jubendradass, R.; Nantia, E.A.; Moundipa, P.F.; Mathur, P.P. Adverse effects of bisphenol A on male reproductive function. Rev. Environ. Contam. Toxicol. 2014, 228, 57–82. [Google Scholar]
  27. Ohore, O.E.; Zhang, S. Endocrine disrupting effects of bisphenol A exposure and recent advances on its removal by water treatment systems. A review. Sci. Afr. 2019, 5, e00135. [Google Scholar] [CrossRef]
  28. Peng, Y.; Wang, J.; Wu, C. Determination of Endocrine Disruption Potential of Bisphenol A Alternatives in Food Contact Materials Using In Vitro Assays: State of the Art and Future Challenges. J. Agric. Food Chem. 2019, 67, 12613–12625. [Google Scholar] [CrossRef] [PubMed]
  29. Jia, M.; Chen, S.; Shi, T.; Li, C.; Wang, Y.; Zhang, H. Competitive Plasmonic Biomimetic Enzyme-Linked Immunosorbent Assay for Sensitive Detection of Bisphenol A. Food Chem. 2021, 344, 128602. [Google Scholar] [CrossRef] [PubMed]
  30. Ma, W.; Wan, S.; Lin, C.; Lin, X.; Xie, Z. Towards online specific recognition and sensitive analysis of bisphenol A by using AuNPs@aptamer hybrid-silica affinity monolithic column with LC-MS. Talanta 2020, 219, 121275. [Google Scholar] [CrossRef]
  31. Martín-Pozo, L.; Martín-Bueno, J.; Moscoso-Ruiz, I.; Zafra-Gómez, A. Chapter 18—Methods of bisphenol A detection by gas chromatography and mass spectrometry (GC-Ms) in human breast milk and foodstuff. In Emerging Contaminants in the Environment; Sarma, H., Dominguez, D.C., Lee, W.-Y., Eds.; Elsevier: Amsterdam, The Netherlands, 2022; pp. 465–493. [Google Scholar]
  32. Owczarek, K.; Waraksa, E.; Kłodzi’nska, E.; Zrobok, Y.; Ozimek, M.; Racho’n, D.; Kudłak, B.; Wasik, A.; Mazerska, Z. Validated GC–MS method for determination of bisphenol A and its five analogues in dietary and nutritional supplements. Microchem. J. 2022, 180, 107643. [Google Scholar] [CrossRef]
  33. Hou, C.; Zhao, L.; Geng, F.; Wang, D.; Guo, L.-H. Donor/acceptor nanoparticle pair-based singlet oxygen channeling homogenous chemiluminescence immunoassay for quantitative determination of bisphenol A. Anal. Bioanal. Chem. 2016, 408, 8795–8804. [Google Scholar] [CrossRef]
  34. Hosseinzadeh, L.; Khoshroo, A.; Adib, K.; Rahimi-Nasrabadi, M.; Ahmadi, F. Determination of Homocysteine Using a Dopamine-Functionalized Graphene Composite. Microchem. J. 2021, 165, 106124. [Google Scholar] [CrossRef]
  35. Sobhani-Nasab, A.; Hoseinpour, S.M.; Rahimi-Nasrabadi, M.; Pourmasoud, S.; Eghbali-Arani, M.; Ahmadi, F.J. Synthesis of Fe3O4/CdWO4/carbon dots heterostructure with excellent visible light photocatalytic stability and activity for degradation of 4-nitrophenol and organic pollutant. Mater. Sci. Mater. Electron. 2021, 32, 26998–27013. [Google Scholar] [CrossRef]
  36. Hafezi, M.; Rostami, M.; Hosseini, A.; Rahimi-Nasrabadi, M.; Fasihi-Ramandi, M.; Badiei, A.; Ahmadi, F.J. Cur-loaded ZnFe2O4@ mZnO@ N-GQDs biocompatible nano-carriers for smart and controlled targeted drug delivery with pH-triggered and ultrasound irradiation. Mol. Liq. 2021, 322, 114875. [Google Scholar] [CrossRef]
  37. Rostami, M.; Nasab, A.S.; Fasihi-Ramandi, M.; Badiei, A.; Rahimi-Nasrabadi, M.; Ahmadi, F. The ZnFe2O4@mZnO–N/RGO nano-composite as a carrier and an intelligent releaser drug with dual pH-and ultrasound-triggered control. New J. Chem. 2021, 45, 4280. [Google Scholar] [CrossRef]
  38. Sohouli, E.; Ghalkhani, M.; Zargar, T.; Joseph, Y.; Rahimi-Nasrabadi, M.; Ahmadi, F.; Plonska-Brzezinska, M.E.; Ehrlich, H. A new electrochemical aptasensor based on gold/nitrogen-doped carbon nano-onions for the detection of Staphylococcus aureus. Electrochim. Acta 2021, 403, 139633. [Google Scholar] [CrossRef]
  39. Ghanbari, M.H.; Khoshroo, A.; Sobati, H.; Ganjali, M.R.; Rahimi-Nasrabadi, M.; Ahmadi, F. An electrochemical sensor based on poly (L-Cysteine)@ AuNPs@ reduced graphene oxide nanocomposite for determination of levofloxacin. Microchem. J. 2019, 147, 198. [Google Scholar] [CrossRef]
  40. Khoshroo, A.; Sadrjavadi, K.; Taran, M.; Fattahi, A. Electrochemical system designed on a copper tape platform as a nonenzymatic glucose sensor. Sens. Actuators B 2020, 325, 128778. [Google Scholar] [CrossRef]
  41. Khoshroo, A.; Hosseinzadeh, L.; Adib, K.; Rahimi-Nasrabadi, M.; Ahmadi, F. Earlier diagnoses of acute leukemia by a sandwich type of electrochemical aptasensor based on copper sulfide-graphene composite. Anal. Chim. Acta 2021, 1146, 1–10. [Google Scholar] [CrossRef]
  42. Zhang, C.; Yi, Y.; Zhou, Y.; Zhou, R.; Zhu, G. Homogeneous electroanalysis coupled with colorimetry dual-mode sensing of silver ion in water based on target-inhibited peroxidase activity of Pt@ZIF-8 nanozyme. Microchem. J. 2024, 197, 109839. [Google Scholar] [CrossRef]
  43. Liu, X.; Yao, Y.; Ying, Y.; Ping, J. Recent advances in nanomaterial-enabled screen-printed electrochemical sensors for heavy metal detection. TrAC Trends Anal. Chem. 2019, 115, 187–202. [Google Scholar] [CrossRef]
  44. Dhaffouli, A.; Salazar-Carballo, P.A.; Carinelli, S.; Holzinger, M.; Barhoumi, H. Improved electrochemical sensor using functionalized silica nanoparticles (SiO2-APTES) for high selectivity detection of lead ions. Mater. Chem. Phys. 2024, 318, 129253. [Google Scholar] [CrossRef]
  45. Baluta, S.; Meloni, F.; Halicka, K.; Szyszka, A.; Zucca, A.; Pilo, M.I.; Cabaj, J. Differential pulse voltammetry and chronoamperometry as analytical tools for epinephrine detection using a tyrosinase-based electrochemical biosensor. RSC Adv. 2022, 12, 25342–25353. [Google Scholar] [CrossRef]
  46. Richardson, S.D.; Kimura, S.Y. Water Analysis: Emerging Contaminants and Current Issues. Anal. Chem. 2020, 92, 473–505. [Google Scholar] [CrossRef]
  47. Moulahi, N.; Echabaane, M.; Chaabene, M.; Baouab, M.H.V.; Ben Chaabane, R. Impedimetric Sensor for Iron (III) Detection Based on Small Molecule (E)-2-((Phenylimino)Methyl) Phenol-Modified Platinum Electrode. J. Iran. Chem. Soc. 2023, 20, 1427–1438. [Google Scholar] [CrossRef]
  48. Mazloum-Ardakani, M.; Eslami, V.; Khoshroo, A. Nickel nitride nanoparticles as efficient electrocatalyst for effective electro-oxidation of ethanol and methanol in alkaline media. Mater. Sci. Eng. B 2018, 229, 201–205. [Google Scholar] [CrossRef]
  49. Mehmandoust, M.; Erk, N.; Karaman, O.; Karimi, F.; Bijad, M.; Karaman, C. Three-dimensional porous reduced graphene oxide decorated with carbon quantum dots and platinum nanoparticles for highly selective determination of azo dye compound tartrazine. Food Chem. Toxicol. 2021, 158, 112698. [Google Scholar] [CrossRef]
  50. Huang, N.; Liu, M.; Li, H.; Zhang, Y.; Yao, S. Synergetic Signal Amplification Based on Electrochemical Reduced Graphene Oxide-Ferrocene Derivative Hybrid and Gold Nanoparticles as an Ultra-Sensitive Detection Platform for Bisphenol A. Anal. Chim. Acta 2015, 853, 249–257. [Google Scholar] [CrossRef]
  51. He, S.; Xia, H.; Chang, F. Enzyme free electrochemical determination of bisphenol A using screen-printed electrode modified by graphdiyne and carbon nanotubes. Microchem. J. 2022, 182, 107858. [Google Scholar] [CrossRef]
  52. Shen, M.; Li, W.; Chen, F.; Chen, L.; Chen, Y.; Chen, S.; Ren, S.; Han, D. A ratiometric electrochemical sensor for bisphenol A detection based on Ag@Fe3O4-rGO composite. Microchem. J. 2023, 186, 108315. [Google Scholar] [CrossRef]
  53. Ma, J.; Yuan, J.; Xu, Y.; Jiang, Y.; Bai, W.; Zheng, J. Ultrasensitive electrochemical determination of bisphenol A in food samples based on a strategy for activity enhancement of enzyme: Layer-by-layer self-assembly of tyrosinase between two-dimensional porphyrin metal–organic framework nanofilms. Chem. Eng. J. 2022, 446, 137001. [Google Scholar] [CrossRef]
  54. Verma, D.; Yadav, A.K.; Mukherjee, M.D.; Solanki, P.R. Fabrication of a sensitive electrochemical sensor platform using reduced graphene oxide-molybdenum trioxide nanocomposite for BPA detection: An endocrine disruptor. J. Environ. Chem. Eng. 2021, 9, 105504. [Google Scholar] [CrossRef]
  55. Rejab, F.; Dardouri, N.E.; Rouis, A.; Echabaane, M.; Nasri, H.; Lakard, B.; Halima, H.B.; Jaffrezic-Renault, N. A Selective Electrochemical Sensor for Bisphenol A Detection Based on Cadmium (II) (bromophenyl)porphyrin and Gold Nanoparticles. Micromachines 2024, 15, 1508. [Google Scholar] [CrossRef] [PubMed]
  56. Luis-Sunga, M.; Carinelli, S.; García, G.; González-Mora, J.L.; Salazar-Carballo, P.A. Electrochemical Detection of Bisphenol A Based on Gold Nanoparticles/Multi-Walled Carbon Nanotubes: Applications on Glassy Carbon and Screen Printed Electrodes. Sensors 2024, 24, 2570. [Google Scholar] [CrossRef] [PubMed]
  57. Fouad, D.M.; El-Said, W.A.; Mohamed, M.B. Spectroscopic characterization of magnetic Fe3O4@Au core shell nanoparticles. Spectrochim. Acta Part A Mol. Biomol. Spectrosc. Source Preview 2015, 140, 392–397. [Google Scholar] [CrossRef]
  58. El-Said, W.A.; Alsulmi, A.; Alshitari, W. Hydrothermal synthesis of Mn3O4 nanorods modified indium tin oxide electrode as an efficient nanocatalyst towards direct urea electrooxidation. PLoS ONE 2022, 17, e0272586. [Google Scholar] [CrossRef]
  59. Khan, F.; Akhtar, N.; Jalal, N.; Hussain, I.; Szmigielski, R.; Hayat, M.Q.; Ahmad, H.B.; El-Said, W.A.; Yang, M.; Janjua, H.A. Carbon-dot wrapped ZnO nanoparticle-based photoelectrochemical sensor for selective monitoring of H2O2 released from cancer cells. Microchim. Acta 2019, 186, 127. [Google Scholar] [CrossRef] [PubMed]
  60. Kim, T.-H.; El-Said, W.A.; Choi, J.-W. Highly sensitive electrochemical detection of potential cytotoxicity of CdSe/ZnS quantum dots using neural cell chip. Biosens. Bioelectron. Source Preview 2012, 32, 266–272. [Google Scholar] [CrossRef] [PubMed]
  61. Amin, H.M.; El-Kady, M.F.; Atta, N.F.; Galal, A. Gold Nanoparticles Decorated Graphene as a High Performance Sensor for Determination of Trace Hydrazine Levels in Water. Electroanalysis 2018, 30, 1757–1766. [Google Scholar] [CrossRef]
  62. Abbas, A.; Amin, H.M.A. Silver nanoparticles modified electrodes for electroanalysis: An updated review and a perspective. Microchem. J. 2022, 175, 107166. [Google Scholar] [CrossRef]
  63. dos Santos, W.T.P.; Amin, H.M.A.; Compton, R.G. A nano-carbon electrode optimized for adsorptive stripping voltammetry: Application to detection of the stimulant selegiline in authentic saliva. Sens. Actuators B Chem. 2019, 279, 433–439. [Google Scholar] [CrossRef]
  64. Gurule, A.C.; Gaikwad, S.S.; Kajale, D.D.; Shinde, V.S.; Jadhav, G.R.; Gaikwad, V.B. Synthesis of magnesium oxide nanoparticles via hydrothermal and sol-gel methods: Charaterization and their application for H2S and NO2 gas sensing. J. Indian Chem. Soc. 2025, 102, 101496. [Google Scholar] [CrossRef]
  65. Desai, P.; Darji, V.; Deshpande, M.P.; Chaki, S.H.; Sutariya, P.G.; Soni, H.; Hirpara, B. Dielectric performance of nanostructured magnesium oxide and effect of cobalt substitution. Mater. Today Commun. 2024, 38, 108022. [Google Scholar] [CrossRef]
  66. Sutradhar, N.; Sinhamahapatra, A.; Pahari, S.K.; Pal, P.; Bajaj, H.C.; Mukhopadhyay, I.; Panda, A.B. Fabrication of Highly Sensitive and Stable Hydroxylamine Electrochemical Sensor Based on Gold Nanoparticles and Metal–Metalloporphyrin Framework Modified Electrode. ACS Appl. Mater. Interfaces 2016, 8, 18173–18181. [Google Scholar] [CrossRef]
  67. Nourozi, B.; Aminian, A.; Fili, N.; Zangeneh, Y.; Boochani, A.; Darabi, P. The electronic and optical properties of MgO monolayer: Based on GGA-mBJ. Results Phys. 2019, 12, 2038–2043. [Google Scholar] [CrossRef]
  68. Manjunatha, K.G.; Swamy, B.E.K.; Madhuchandra, H.D.; Gururaj, K.J.; Vishnumurthy, K.A. Synthesis and characterization of MgO nanoparticle and their surfactant modified carbon paste electrode sensing for paracetamol. Sens. Int. 2021, 2, 100127. [Google Scholar] [CrossRef]
  69. Manjunatha, K.G.; Swamy, B.E.K.; Jayaprakash, G.K.; Vishnumurthy, K.A. Synthesis of MgO Nanoparticle Surfactant Free Modified Carbon Paste Electrode: A Voltammetric Study. Anal. Bioanal. Electrochem. 2022, 14, 921–933. [Google Scholar]
  70. Amir, A.; Faisal, M.; Hussain, M.A.; Haq, E.U.; Raza, K.; Rehman, Z.U. A facile synthesis of nano-magnesia by ultrasonication assisted co-precipitation method for antibacterial activity, in: MATEC Web of Conferences. EDP Sci. 2024, 398, 01037. [Google Scholar] [CrossRef]
  71. Toprak, B.Ç.; Efkere, H.I.; Aydın, S.Ş.; Tataroğlu, A.; Özçelik, S. Structural, morphological, optical and electrical characterization of MgO thin films grown by sputtering technique on different substrates. J. Mater. Sci. Mater. Electron. 2024, 35, 1389. [Google Scholar] [CrossRef]
  72. Azhdar, B. Influence of fuel-to-oxidizer ratio, potential of hydrogen and annealing temperature on the structural and optical properties of nanocrystalline MgO powders synthesized by the hydrothermal method. J. Exp. Nanosci. 2023, 18, 2276278. [Google Scholar] [CrossRef]
  73. Mei, S.; Jiang, F.; Liu, N.; Feng, Z.; Zheng, Y.; Yang, W.; Zhang, N. Sol-gel synthesis of magnesium oxide nanoparticles and their evaluation as a therapeutic agent for the treatment of osteoarthritis. Nanomedicine 2024, 19, 1867–1878. [Google Scholar] [CrossRef]
  74. Krishna, B.V.; Rao, P.T.; Lakshmi, B.D.; Vasudha, K.; Basha, S.E.; Kumar, B.P.; Kiran, P.S.S.; Chandra, K.S.; Ramachandra, R.K. Green fabrication of tinospora cordifolia-derived MgO nanoparticles: Potential for diabatic control and oxidant protection. Next Mater. 2024, 3, 100171. [Google Scholar] [CrossRef]
  75. Kumari, S.V.G.; Pakshirajan, K.; Pugazhenthi, G. Synthesis and characterization of MgO nanostructures: A comparative study on the effect of preparation route. Mater. Chem. Phys. 2023, 294, 127036. [Google Scholar] [CrossRef]
  76. Lone, G.A.; Nazir, N.; Balal, M.; Ikram, M. Thin film deposition of undoped and Nidoped cobalt ferrite on MgO (110) substrates using pulsed laser deposition technique. Thin Solid. Film. 2024, 791, 140243. [Google Scholar] [CrossRef]
  77. Sharma, M.; Jeevanandam, P.J. Synthesis of magnesium oxide particles with stacks of plates morphology. Alloys Compd. 2011, 509, 7881–7885. [Google Scholar] [CrossRef]
  78. Ahmada, K.; Mobin, S.M. High surface area 3D-MgO flowers as the modifier for the working electrode for efficient detection of 4-chlorophenol. Nanoscale Adv. 2019, 1, 719. [Google Scholar] [CrossRef] [PubMed]
  79. Pilarska, A.A.; Klapiszewski, Ł.; Jesionowski, T. Recent development in the synthesis, modification, and application of Mg(OH)2 and MgO: A review. Powder Technol. 2017, 319, 373–407. [Google Scholar] [CrossRef]
  80. Dong, X.X.; Li, M.Y.; Feng, N.N.; Sun, Y.M.; Yang, C.; Xu, Z.L. A nanoporous MgO-based nonenzymatic electrochemical sensor for rapid screening of hydrogen peroxide in milk. RSC Adv. 2015, 5, 86485–86489. [Google Scholar] [CrossRef]
  81. Singh, N.; Singh, P.K.; Singh, M.; Tandon, P.; Singh, S.K.; Singh, S. Fabrication and characterization of polyaniline, polyaniline/MgO (30%), and polyaniline/MgO (40%) nanocomposites for their employment in LPG sensing at room temperature. J. Mater. Sci. Mater. Electron. 2019, 30, 4487–4498. [Google Scholar] [CrossRef]
  82. Abinaya, S.; Kavitha, H.P. Magnesium Oxide Nanoparticles: Effective Antilarvicidal and Antibacterial Agents. ACS Omega 2023, 8, 5225–5233. [Google Scholar] [CrossRef] [PubMed]
  83. Dekermenjian, M.; Ruediger, A.P.; Merlen, A. Raman spectroscopy investigation of magnesium oxide nanoparticles. RSC Adv. 2023, 13, 26683–26689. [Google Scholar] [CrossRef]
  84. Athar, T.; Hakeem, A.; Ahmed, W. Synthesis of MgO Nanopowder via Non Aqueous Sol–Gel Method. Adv. Sci. Lett. 2012, 5, 27–29. [Google Scholar] [CrossRef]
  85. Muhaymin, A.; Mohamed, H.E.A.; Hkiri, K.; Safdar, A.; Azizi, S. Green synthesis of magnesium oxide nanoparticles using Hyphaene thebaica extract and their photocatalytic activities. Sci. Rep. 2024, 14, 20135. [Google Scholar] [CrossRef] [PubMed]
  86. Hema, M. Synthesis of hierarchical structured MgO by sol-gel method. Nano Bull. 2013, 2, 130106. [Google Scholar]
  87. Rezaei, M.; Khajenoori, M.; Nematollahi, B. Synthesis of high surface area nanocrystalline MgO by pluronic P123 triblock copolymer surfactant. Powder Technol. 2011, 205, 112–116. [Google Scholar] [CrossRef]
  88. Geler-Kremer, J.; Posadas, A.B.; Demkov, A.A. Preparation of clean MgO surface by oxygen plasma: Comparison with standard substrate cleaning procedures. J. Vac. Sci. Technol. B 2020, 38, 062201. [Google Scholar] [CrossRef]
  89. Fonoll-Rubio, R.; Placidi, M.; Hoelscher, T.; Thomere, A.; Li-Kao, Z.J.; Guc, M.; Izquierdo-Roca, V.; Scheer, R.; Pérez-Rodríguez, A. Characterization of the Stability of Indium Tin Oxide and Functional Layers for Semitransparent Back-Contact Applications on Cu(in,Ga)Se2 Solar Cells. Sol. RRL 2022, 6, 2101071. [Google Scholar] [CrossRef]
  90. Atta, N.F.; Ahmed, R.A.; Amin, H.M.A.; Galal, A. Monodispersed Gold Nanoparticles Decorated Carbon Nanotubes as an Enhanced Sensing Platform for Nanomolar Detection of Tramadol. Electroanalysis 2012, 24, 2135–2146. [Google Scholar] [CrossRef]
  91. Jaballah, M.B.; Messaoud, N.B.; Dridi, C. Development of cost-effective and sustainable sensing nanoplatform based on green AgNPs for the determination of BPA in water. J. Mater. Sci. 2022, 33, 6981–6998. [Google Scholar] [CrossRef]
  92. He, L.; Yang, Y.; Kim, J.; Yao, L.; Dong, X.; Li, T.; Piao, Y. Multi-layered enzyme coating on highly conductive magnetic biochar nanoparticles for bisphenol A sensing in water. Chem. Eng. J. 2020, 384, 123276. [Google Scholar] [CrossRef]
  93. Maximiano, L.V.; Correa, L.B.; Gomes-da-Silva, N.C.; da Costa, L.S.; Da Silva, M.G.P.; Chaves, A.V.; Franco, M.L.; Fechine, P.B.A.; de Menezes, A.S.; Santos-Oliveira, R.; et al. Magnesium whitlockite nanoparticles: Hydrothermal synthesis, anti-inflammatory and anti-cancer potential. Colloids Surf. B Biointerfaces 2024, 239, 113931. [Google Scholar] [CrossRef]
  94. Semerjian, L.; Alawadhi, N.; Nazer, K. Detection of bisphenol A in thermal paper receipts and assessment of human exposure: A case study from Sharjah, United Arab Emirates. PLoS ONE 2023, 18, e0283675. [Google Scholar] [CrossRef]
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Figure 1. (a) SEM of MgO NPs-modified ITO electrode, (b) FTIR of MgO NPs, (c) XRD of MgO NPs, and (d) Raman spectroscopy of MgO NPs-modified ITO electrode.
Figure 1. (a) SEM of MgO NPs-modified ITO electrode, (b) FTIR of MgO NPs, (c) XRD of MgO NPs, and (d) Raman spectroscopy of MgO NPs-modified ITO electrode.
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Figure 2. (a) Cyclic voltammograms of 5 mmol L−1 [Fe(CN)6]3−/4− at (black curve) ITO electrode (black curve) and MgO/ITO (blue curve), (b) cyclic voltammograms of BPA at ITO electrode (black curve) and MgO/ITO in PBS (red curve), and (c) cyclic voltammogram of BPA at MgO/ITO electrode.
Figure 2. (a) Cyclic voltammograms of 5 mmol L−1 [Fe(CN)6]3−/4− at (black curve) ITO electrode (black curve) and MgO/ITO (blue curve), (b) cyclic voltammograms of BPA at ITO electrode (black curve) and MgO/ITO in PBS (red curve), and (c) cyclic voltammogram of BPA at MgO/ITO electrode.
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Scheme 1. (a) Electrochemical oxidation of BPA, and (b) hydrothermal growth of MgO NPs over ITO electrodes.
Scheme 1. (a) Electrochemical oxidation of BPA, and (b) hydrothermal growth of MgO NPs over ITO electrodes.
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Figure 3. (a) Cyclic voltammograms of 2 μmol L−1 in different pH (4–10), (b) The peak current versus pH, and (c) Interference study of BPA (10 μmol L−1) concentration with some interferents.
Figure 3. (a) Cyclic voltammograms of 2 μmol L−1 in different pH (4–10), (b) The peak current versus pH, and (c) Interference study of BPA (10 μmol L−1) concentration with some interferents.
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Figure 4. (a) LSV voltammograms of different concentrations BPA (0.1–15 μmol L−1), (b) relationship between the BPA concentrations and the corresponding current, (c) DPV voltammograms of different concentrations of BPA (1.13 nmol L−1–10 μmol L−1), and (d) relationship between the BPA concentrations and the corresponding current.
Figure 4. (a) LSV voltammograms of different concentrations BPA (0.1–15 μmol L−1), (b) relationship between the BPA concentrations and the corresponding current, (c) DPV voltammograms of different concentrations of BPA (1.13 nmol L−1–10 μmol L−1), and (d) relationship between the BPA concentrations and the corresponding current.
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Figure 5. (a–o) DPV voltammograms of the extractions from the 15 collected thermal paper samples.
Figure 5. (a–o) DPV voltammograms of the extractions from the 15 collected thermal paper samples.
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Table 1. Comparison of the performance of our proposed BPA sensor with previously reported sensors.
Table 1. Comparison of the performance of our proposed BPA sensor with previously reported sensors.
SensorLinear Range (μmol L−1)LOD (nmol L−1)Reference
Ag@Fe3O4-rGO/GCE 0.1–1022[52]
Tyr@Cu–TCPP/GCE 0.0035–18.9 1.2[53]
rGO/MoO3NPs/ITO 0.82–760.12[54]
AgNPs/f-MWCNT/GCE0.3–0.8220[91]
ML-TYR/Mag-BCNPs-COOH/MGCE 0.01–1.012.8[92]
MgO NPs/ITO0.05–101.13This work
Table 2. BPA concentration calculated in different thermal paper samples based on DPV measurements.
Table 2. BPA concentration calculated in different thermal paper samples based on DPV measurements.
Sample NumberBPA Concentration (μmol L−1)
10.047
20
30.019
40.04
50.0148
61.33
70.0139
80.0229
90.141
100.0189
110
120.68
130.835
140
150
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Akhdhar, A.; El-Said, W.A. In Situ Growth of Magnesium Oxide Nanoparticles on ITO Electrodes as Electrocatalysts for Detecting Bisphenol A in Thermal Paper. Catalysts 2025, 15, 901. https://doi.org/10.3390/catal15090901

AMA Style

Akhdhar A, El-Said WA. In Situ Growth of Magnesium Oxide Nanoparticles on ITO Electrodes as Electrocatalysts for Detecting Bisphenol A in Thermal Paper. Catalysts. 2025; 15(9):901. https://doi.org/10.3390/catal15090901

Chicago/Turabian Style

Akhdhar, Abdullah, and Waleed A. El-Said. 2025. "In Situ Growth of Magnesium Oxide Nanoparticles on ITO Electrodes as Electrocatalysts for Detecting Bisphenol A in Thermal Paper" Catalysts 15, no. 9: 901. https://doi.org/10.3390/catal15090901

APA Style

Akhdhar, A., & El-Said, W. A. (2025). In Situ Growth of Magnesium Oxide Nanoparticles on ITO Electrodes as Electrocatalysts for Detecting Bisphenol A in Thermal Paper. Catalysts, 15(9), 901. https://doi.org/10.3390/catal15090901

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