sensors-logo

Journal Browser

Journal Browser

Special Issue "Colorimetric and Fluorescent Sensors 2018"

A special issue of Sensors (ISSN 1424-8220). This special issue belongs to the section "Chemical Sensors".

Deadline for manuscript submissions: closed (31 October 2018).

Special Issue Editors

Prof. Dr. Jong Seung Kim
grade E-Mail Website
Guest Editor
Department of Chemistry, Korea University, Seoul 02841, Korea
Interests: supramolecular chemistry; drug delivery system; fluorescent probes; fluorescent imaging; therapeutics
Special Issues and Collections in MDPI journals
Prof. Min Hee Lee
E-Mail Website
Guest Editor
Department of Chemistry, Sookmyung Women's University, Cheongpa-dong 2-ga, Seoul, 140-742, Korea
Interests: host–guest chemistry; chemosensors; chemodosimeters; drug delivery system; theranostics; anion and cation sensing
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue, titled “Colorimetric and Fluorescent Sensors 2018”, in Sensors, an interdisciplinary journal dedicated to covering research and developments in the field of colorimetric and fluorescent sensors and actuators. The scope of the special issue encompasses, but is not restricted to, the following areas: Colorimetric and fluorescent sensing principles and mechanisms, biosensors, analytical chemistry, and biomedical applications .

Prof. Jong Seung Kim
Prof. Min Hee Lee
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sensors is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • colorimetry
  • fluorescence
  • sensors
  • biomaterials
  • host-guest chemistry

Published Papers (16 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
Hand-held Colorimetry Sensor Platform for Determining Salivary α-Amylase Activity and Its Applications for Stress Assessment
Sensors 2019, 19(7), 1571; https://doi.org/10.3390/s19071571 - 01 Apr 2019
Cited by 4 | Viewed by 1538
Abstract
This study develops a hand-held stress assessment meter with a chemically colorimetric strip for determining salivary α-amylase activity, using a 3,5 dinitrosalicylic acid (DNS) assay to quantify the reducing sugar released from soluble starch via α-amylase hydrolysis. The colorimetric reaction is produced by [...] Read more.
This study develops a hand-held stress assessment meter with a chemically colorimetric strip for determining salivary α-amylase activity, using a 3,5 dinitrosalicylic acid (DNS) assay to quantify the reducing sugar released from soluble starch via α-amylase hydrolysis. The colorimetric reaction is produced by heating the strip with a mini polyester heater plate at boiling temperature to form a brick red colored product, which measured at 525 nm wavelength. This investigation describes in detail the design, construction, and performance evaluation of a hand-held α-amylase activity colorimeter with a light emitted diode (LED) and photo-detector with built-in filters. The dimensions and mass of the proposed prototype are only 120 × 60 × 60 mm3 and 200 g, respectively. This prototype has an excellent correlation coefficient (>0.995), comparable with a commercial ultraviolet–visible spectroscope, and has a measurable α-amylase activity range of 0.1–1.0 U mL−1. The hand-held device can measure the salivary α-amylase activity with only 5 μL of saliva within 12 min of testing. This sensor platform effectively demonstrates that the level of salivary α-amylase activity increases more significantly than serum cortisol, the other physiological stressor biomarker, under physiologically stressful exercise conditions. Thus, this work demonstrates that the hand-held α-amylase activity meter is an easy to use and cost-effective stress assessment tool for psychoneuroendocrinology research. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Graphical abstract

Article
A Sensitive Near-Infrared Fluorescent Probe for Detecting Heavy Metal Ag+ in Water Samples
Sensors 2019, 19(2), 247; https://doi.org/10.3390/s19020247 - 10 Jan 2019
Cited by 11 | Viewed by 1694
Abstract
Silver is a common catalyst in industrial production, and the frequent use of Ag+ can cause water pollution. Thus, the detection of Ag+ in the environment is necessary to determine the level of pollution from silver. In this work, we designed [...] Read more.
Silver is a common catalyst in industrial production, and the frequent use of Ag+ can cause water pollution. Thus, the detection of Ag+ in the environment is necessary to determine the level of pollution from silver. In this work, we designed a new, highly selective near-infrared (NIR) fluorescent probe QCy to detect Ag+. The probe exhibits “turn-off” fluorescence quenching responses at 760 nm towards Ag+ over other relevant cations, with outstanding sensitivity and a low detection limit (0.03 µM), which is considerably lower than the standard of the World Health Organization (WHO) for drinking water (0.9 µM). Meanwhile, QCy showed a very good linearity at a low concentration of Ag+ with a ‘naked eye’ visible color change of solution from blue to red. The probe has been applied successfully for the detection of Ag+ in real water samples. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Hg2+-Promoted Spirolactam Hydrolysis Reaction: A Design Strategy for the Highly Selective Sensing of Hg2+ over other Metal Ions in Aqueous Media
Sensors 2019, 19(1), 128; https://doi.org/10.3390/s19010128 - 02 Jan 2019
Cited by 3 | Viewed by 2036
Abstract
A mercury sensor (N-(rhodamine-6G)lactam-ethylenediamine-4-dimethylamino-cinnamaldehyde—RLED) based on the Hg2+-promoted hydrolysis reaction has been designed and developed with a combination of theoretical calculations and experimental investigations. The interaction between RLED and Hg2+ goes through a fast-initial stage with formation of [...] Read more.
A mercury sensor (N-(rhodamine-6G)lactam-ethylenediamine-4-dimethylamino-cinnamaldehyde—RLED) based on the Hg2+-promoted hydrolysis reaction has been designed and developed with a combination of theoretical calculations and experimental investigations. The interaction between RLED and Hg2+ goes through a fast-initial stage with formation of a 1:1 complex, followed by a slow hydrolysis process. The formation of durable intermediate complexes is due to quite a long hydrolysis reaction time. As a result, RLED can selectively detect Hg2+ in the presence of other metal ions, with a detection limit of 0.08 μM for the colorimetric method, and of 0.008 μM with the fluorescent method. In addition, the RLED sensor can work in a solution with a small amount of organic solvent, with a wide pH range from 5 to 10. The time-dependent density functional theory has been used for investigations of the excitation and de-excitation processes in RLED, intermediate complexes, and reaction products, thereby clarifying the changes in the fluorescence intensity before and after the RLED interacts with Hg2+ ions. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Graphical abstract

Article
A Fluorescence Sensing Determination of 2,4,6-Trinitrophenol Based on Cationic Water-Soluble Pillar[6]arene Graphene Nanocomposite
Sensors 2019, 19(1), 91; https://doi.org/10.3390/s19010091 - 28 Dec 2018
Cited by 9 | Viewed by 1560
Abstract
We describe a selective and sensitive fluorescence platform for the detection of trinitrophenol (TNP) based on competitive host–guest recognition between pyridine-functionalized pillar[6]arene (PCP6) and a probe (acridine orange, AO) that used PCP6-functionalized reduced graphene (PCP6-rGO) as the receptor. TNP is an electron-deficient and [...] Read more.
We describe a selective and sensitive fluorescence platform for the detection of trinitrophenol (TNP) based on competitive host–guest recognition between pyridine-functionalized pillar[6]arene (PCP6) and a probe (acridine orange, AO) that used PCP6-functionalized reduced graphene (PCP6-rGO) as the receptor. TNP is an electron-deficient and negative molecule, which is captured by PCP6 via electrostatic interactions and π–π interactions. Therefore, a selective and sensitive fluorescence probe for TNP detection is developed. It has a low detection limit of 0.0035 μM (S/N = 3) and a wider linear response of 0.01–5.0 and 5.0–125.0 for TNP. The sensing platform is also used to test TNP in two water and soil samples with satisfying results. This suggests that this approach has potential applications for the determination of TNP. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Determination of Trace Amounts of Hydrofluoric Acid in Non-Aqueous Solutions by the Coulometric Titration Method
Sensors 2018, 18(12), 4439; https://doi.org/10.3390/s18124439 - 15 Dec 2018
Cited by 1 | Viewed by 2284
Abstract
For monitoring of trace amounts of hydrofluoric acid in the organic fluorine chemical industry, a facile method for determination of the hydrofluoric acid in an ethanol solution of lithium chloride, by coulometric titration, was proposed. Relying on homemade acid–base coulometric autotitrator, the electrolyte [...] Read more.
For monitoring of trace amounts of hydrofluoric acid in the organic fluorine chemical industry, a facile method for determination of the hydrofluoric acid in an ethanol solution of lithium chloride, by coulometric titration, was proposed. Relying on homemade acid–base coulometric autotitrator, the electrolyte was 0.50 mol·L−1 LiCl ethanol solution and the constant current intensity was 0.2–2 mA. As for the working electrode pair, a platinum plate was used as a working electrode, and a platinum wire was used as an auxiliary electrode. The indicating electrode was the pH composite glass electrode and the titration endpoint was pH 5.50. The results showed that the relative standard deviation was below 2.0%, as the content of the hydrofluoric acid was between 2 μg to 100 μg. The recovery rate was 99.0–102.0%. This proposed route has the advantages of simplicity, convenience, quickness, accuracy, and automation, which can be applied to the accurate determination of trace amounts of hydrofluoric acid, in non-aqueous solutions. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Evaluation of the Characteristics and Coating Film Structure of Polymer/Ceramic Pressure-Sensitive Paint
Sensors 2018, 18(11), 4041; https://doi.org/10.3390/s18114041 - 20 Nov 2018
Cited by 9 | Viewed by 1623
Abstract
Polymer/ceramic pressure-sensitive paint (PC-PSP), which incorporates a high percentage of particles in the binder layer, is proposed in order to improve the characteristics of PSP. The procedure for embedding particles into the binder layer was modified. In the conventional procedure, dye is adsorbed [...] Read more.
Polymer/ceramic pressure-sensitive paint (PC-PSP), which incorporates a high percentage of particles in the binder layer, is proposed in order to improve the characteristics of PSP. The procedure for embedding particles into the binder layer was modified. In the conventional procedure, dye is adsorbed onto a polymer/ceramic coating film (denoted herein as a dye-adsorbed (D-adsorbed) PSP). In the new procedure, the mixture of a dye and particles is adsorbed onto a polymer coating film (denoted herein as the particle/dye-adsorbed (PD-adsorbed) PSP). The effect of particle mass content on PSP characteristics was investigated. In addition, the effect of solvent on PSP characteristics and film structure were evaluated for the PD-adsorbed PSP. As a result, the difference in the PSP characteristics between the two types of PSP was clarified. Although surface roughness and time response increase with increased mass content of particles for both D- and PD-adsorbed PSPs, the critical pigment volume concentration (CPVC) for the PD-adsorbed PSP is smaller than that of the D-adsorbed PSP (88 wt% and 93 wt%, respectively). The PD-adsorbed PSP has a higher frequency response comparing with the D-adsorbed PSP while maintaining the same surface roughness. Observation by scanning electron microscope showed that the CPVC of the PC-PSP is governed primarily by surface structure. The coating film structure can be roughly classified into two states depending on the particle mass content. One is a state in which the coating film consisted of two layers: a lower particle-rich layer and an upper polymer-rich layer. This type of structure was observed in the PD-adsorbed PSP as well as in the D-adsorbed PSP. In the other state, polymer and particles are homogeneously distributed in the film, and pores are formed. This difference in the coating structure results in a change in the time response. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
A Fluorescence Sensor Capable of Real-Time Herbicide Effect Monitoring in Greenhouses and the Field
Sensors 2018, 18(11), 3771; https://doi.org/10.3390/s18113771 - 05 Nov 2018
Cited by 7 | Viewed by 1394
Abstract
Herbicide resistant weeds need to be identified early so that yield loss can be avoided by applying proper field management strategies. A novel chlorophyll-fluorescence-imaging sensor has been developed to conduct real-time herbicide effect evaluation. In this research, greenhouse and field experiments were conducted [...] Read more.
Herbicide resistant weeds need to be identified early so that yield loss can be avoided by applying proper field management strategies. A novel chlorophyll-fluorescence-imaging sensor has been developed to conduct real-time herbicide effect evaluation. In this research, greenhouse and field experiments were conducted to calibrate the capability of the sensor in monitoring herbicide effects on different biotypes of two grass weeds (Alopecurus myosuroides, Apera spica-venti) in southwestern Germany. Herbicides with different modes of action were applied for the effect monitoring. Chlorophyll fluorescence yield of the plants was measured 3–15 days after treatment (DAT) using the new fluorescence sensor. Visual assessment of the weeds was carried out on 21 DAT. The results showed that the maximal PS II quantum yield (Fv/Fm) of herbicide sensitive weeds was significantly lower than the values of resistant populations in 5 DAT. The new technology was capable of quickly identifying the herbicide’s effect on plants. It can be used to optimize management strategies to control herbicide resistant weeds. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Ultrafast and Energy-saving Synthesis of Nitrogen and Chlorine Co-doped Carbon Nanodots via Neutralization Heat for Selective Detection of Cr(VI) in Aqueous Phase
Sensors 2018, 18(10), 3416; https://doi.org/10.3390/s18103416 - 11 Oct 2018
Cited by 9 | Viewed by 1265
Abstract
In this work, it is presented for the first time that nitrogen and chlorine co-doped carbon nanodots (N,Cl-CDs) were synthesized by simply mixing glucose, concentrated hydrochloric acid (HCl), and 1,2-ethylenediamine (EDA). No external heat was employed; the neutralization reaction [...] Read more.
In this work, it is presented for the first time that nitrogen and chlorine co-doped carbon nanodots (N,Cl-CDs) were synthesized by simply mixing glucose, concentrated hydrochloric acid (HCl), and 1,2-ethylenediamine (EDA). No external heat was employed; the neutralization reaction served as the heat source. The glucose served as the carbon source while EDA and HCl were the N and Cl dopants, respectively. The fluorescence of N,Cl-CDs was adequately quenched by hexavalent chromium Cr(VI) based on a combination of dynamic quenching and inner filter effect (IFE). Accordingly, an efficient N,Cl-CDs-based fluorescence probe was established for sensitive and selective detection of Cr(VI). The proposed fluorescence sensor provides a linear recognition range for Cr(VI) determination from 3 to 40 µM with a limit of detection (LOD) of 0.28 µM (14.6 µg/L). The proposed fluorescence method was successfully utilized to detect Cr(VI) in different water samples with satisfactory results. The spike recoveries vary from 97.01% to 103.89% with relative standard deviations (RSDs) of less than 0.82%. This work highlights the development of a simple, ultrafast, and energy-saving one-step synthetic route to fabricate N,Cl-CDs for highly selective and sensitive detection of Cr(VI) in real water samples. It is anticipated that the proposed fluorescence method could be further explored and widely used for Cr(VI) detection in the environmental industry. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Graphical abstract

Article
A Fluorescent Cy7-Mercaptopyridine for the Selective Detection of Glutathione over Homocysteine and Cysteine
Sensors 2018, 18(9), 2897; https://doi.org/10.3390/s18092897 - 01 Sep 2018
Cited by 6 | Viewed by 2008
Abstract
We describe a near-infrared (NIR) fluorescent probe 1 for the selective detection of GSH over Hcy and Cys under physiological conditions. Probe 1 was composed of Cy7 as a NIR dye and 2-mercaptopyridine as a GSH-reactive site and fluorescence quencher. In the presence [...] Read more.
We describe a near-infrared (NIR) fluorescent probe 1 for the selective detection of GSH over Hcy and Cys under physiological conditions. Probe 1 was composed of Cy7 as a NIR dye and 2-mercaptopyridine as a GSH-reactive site and fluorescence quencher. In the presence of GSH, the 2-mercaptopyridine functionality of probe 1 was replaced by the thiolate group of GSH through a nucleophilic substitution reaction with a fluorescence increase at 818 nm. The probe was found to be highly selective for GSH over Hcy, Cys, and other tested potential interferants, including ROS and metal ions. In addition, probe 1 successfully displayed fluorescence changes in response to changing the GSH concentrations in MDA-MB-231 cells in the presence of external agents i.e., N-acetyl-l-cysteine (NAC; as GSH inducer) or buthionine sulfoximine (BSO; as GSH inhibitor). We envision that probe 1 will serve as a promising sensing tool for monitoring the changes of the GSH level and the understanding of the roles of GSH under physiological and pathological conditions. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Graphical abstract

Article
Development of Colorimetric and Ratiometric Fluorescence Membranes for Detection of Nitrate in the Presence of Aluminum-Containing Compounds
Sensors 2018, 18(9), 2883; https://doi.org/10.3390/s18092883 - 31 Aug 2018
Cited by 3 | Viewed by 1519
Abstract
In this study, a quantitative analysis of nitrate in aqueous solution was performed through the combination of an oxazine170 perchlorate–ethyl cellulose (O17-EC) membrane with aluminum-containing compounds. Aluminum of Devarda’s alloy (DA) or a clay hydrotalcite (HT) was employed for the reduction of nitrate [...] Read more.
In this study, a quantitative analysis of nitrate in aqueous solution was performed through the combination of an oxazine170 perchlorate–ethyl cellulose (O17-EC) membrane with aluminum-containing compounds. Aluminum of Devarda’s alloy (DA) or a clay hydrotalcite (HT) was employed for the reduction of nitrate to produce ammonia, and the produced ammonia was detected by the O17-EC membrane. The method of combining the O17-EC membrane with aluminum compounds has showed a broad detection range of nitrate. That is, the DA was combined with the O17-EC membrane and showed the linear nitrate detection ranges of 1–10 mM and 10–100 mM, while the O17-EC membrane immobilized with the clay HT showed a linear detection range of 0.1–1 mM nitrate. The visual color transition of the nitrate-sensing membranes at different nitrate concentrations was clearly observed under sunlight or irradiation of a light-emitting diode (LED) at an excitation wavelength of 470 nm (LED470). Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Highly Sensitive and Selective Colorimetric Detection of Methylmercury Based on DNA Functionalized Gold Nanoparticles
Sensors 2018, 18(8), 2679; https://doi.org/10.3390/s18082679 - 15 Aug 2018
Cited by 8 | Viewed by 1641
Abstract
A new colorimetric detection of methylmercury (CH3Hg+) was developed, which was based on the surface deposition of Hg enhancing the catalytic activity of gold nanoparticles (AuNPs). The AuNPs were functionalized with a specific DNA strand (HT7) recognizing [...] Read more.
A new colorimetric detection of methylmercury (CH3Hg+) was developed, which was based on the surface deposition of Hg enhancing the catalytic activity of gold nanoparticles (AuNPs). The AuNPs were functionalized with a specific DNA strand (HT7) recognizing CH3Hg+, which was used to capture and separate CH3Hg+ by centrifugation. It was found that the CH3Hg+ reduction resulted in the deposition of Hg onto the surface of AuNPs. As a result, the catalytic activity of the AuNPs toward the chromogenic reaction of 3,3,5,5-tetramethylbenzidine (TMB)-H2O2 was remarkably enhanced. Under optimal conditions, a limit of detection of 5.0 nM was obtained for CH3Hg+ with a linear range of 10–200 nM. We demonstrated that the colorimetric method was fairly simple with a low cost and can be conveniently applied to CH3Hg+ detection in environmental samples. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
A Simple and Effective Colorimetric Assay for Glucose Based on MnO2 Nanosheets
Sensors 2018, 18(8), 2525; https://doi.org/10.3390/s18082525 - 02 Aug 2018
Cited by 8 | Viewed by 1757
Abstract
Simple and effective methods for the detection of the level of blood glucose are closely linked to the monitoring of people’s health. In the study, MnO2 nanosheets with absorption range of 300 nm~500 nm and obvious yellow color were easily prepared and [...] Read more.
Simple and effective methods for the detection of the level of blood glucose are closely linked to the monitoring of people’s health. In the study, MnO2 nanosheets with absorption range of 300 nm~500 nm and obvious yellow color were easily prepared and applied to detect glucose through their absorbance and color. The proposed method is based on the fact that a specific concentration of glucose can be quantitatively transformed into hydrogen peroxide (H2O2) under the catalytic effect of glucose oxidase. Based on the redox reaction of MnO2 with H2O2, yellow MnO2 can be converted into colorless Mn2+ to monitor the concentration of glucose. Under optimal conditions, a simple and effective visual assay for the sensitive and reliable detection of glucose was developed. The linear range was estimated to the range from 0 μM to 100 μM, with a detection limit of 12.8 μM. Furthermore, the proposed colorimetric assay based on MnO2 nanosheets can effectively detect blood glucose of clinical serum samples with accuracy and convenience. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Simultaneous Detection of Adenosine Triphosphate and Glucose Based on the Cu-Fenton Reaction
Sensors 2018, 18(7), 2151; https://doi.org/10.3390/s18072151 - 04 Jul 2018
Cited by 4 | Viewed by 1689
Abstract
Both adenosine triphosphate (ATP) and glucose are important to human health, and their abnormal levels are closely related to angiocardiopathy and hypoglycaemia. Therefore, the simultaneous determination of ATP and glucose with a single test mode is highly desirable for disease diagnostics and early [...] Read more.
Both adenosine triphosphate (ATP) and glucose are important to human health, and their abnormal levels are closely related to angiocardiopathy and hypoglycaemia. Therefore, the simultaneous determination of ATP and glucose with a single test mode is highly desirable for disease diagnostics and early recognition. Herein, a new fluorescence on/off switch sensing platform is developed by carbon nanodots (CNDs) to detect ATP and glucose simultaneously. The fluorescence of CNDs can be quenched by Cu2+ and hydrogen peroxide (H2O2), due to the formation of hydroxyl radicals (·OH) produced in the Cu-Fenton reaction. Based on the high affinity of Cu2+ with ATP, the fluorescence of CNDs will recover effectively after adding ATP. Additionally, glucose can be efficiently catalyzed by glucose oxidase (GOx) to generate H2O2, so the platform can also be utilized to analyze glucose. Under optimum conditions, this sensing platform displays excellent sensitivity and the linear ranges are from 0.1 to 7 μM for ATP with a limit of detection (LOD) of 30.2 nM, and from 0.1 to 7 mM for glucose with a LOD 39.8 μM, respectively. Benefiting from the high sensitivity and selectivity, this sensing platform is successfully applied for simultaneous detection of ATP and glucose in human serum samples with satisfactory recoveries. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Article
Coumarin Probe for Selective Detection of Fluoride Ions in Aqueous Solution and Its Bioimaging in Live Cells
Sensors 2018, 18(7), 2042; https://doi.org/10.3390/s18072042 - 26 Jun 2018
Cited by 12 | Viewed by 2286
Abstract
We have synthesized novel coumarin-based fluorescent chemosensors for detection of fluoride ions in aqueous solution. The detection mechanism relied on a fluoride-mediated desilylation triggering fluorogenic reaction and a strong interaction between fluoride and the silicon center. In this work, the hydroxyl-decorated coumarins containing [...] Read more.
We have synthesized novel coumarin-based fluorescent chemosensors for detection of fluoride ions in aqueous solution. The detection mechanism relied on a fluoride-mediated desilylation triggering fluorogenic reaction and a strong interaction between fluoride and the silicon center. In this work, the hydroxyl-decorated coumarins containing oxysilyl moiety have been synthesized through the aldehyde-functionalized coumarins. The optical responses toward fluoride, as well as aqueous stability studies of both aldehyde and hydroxyl functionalized coumarins, have been investigated. Due to the highest fluorescence enhancement upon the addition of fluoride and good stability in aqueous solution, the hydroxyl-decorated coumarin connected with the bulky tert-butyldiphenyloxysilyl group (-OSitBuPh2) has been selected for further investigation of its potential as a fluoride sensor. This hydroxyl-decorated coumarin can selectively sense fluoride ions in aqueous media (contain 0.8% MeCN) with desirable response times (40 min). The limit of detection of this compound was determined as 0.043 ppm, satisfying the standard fluoride level (0.7 ppm) in drinking water recommended by U.S. Department of Health and Human Services. The application of this silyl-capped coumarin derivative for fluoride analysis in collected water samples displayed satisfactory analytical accuracy (<5% error). Finally, this compound was successfully employed in fluorescence bioimaging of fluoride ions in human liver cancer cells, indicating its excellent cell permeability, ability to retain inside the living cells, and good stability under physiological conditions. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Review

Jump to: Research

Review
Cholinesterases and Engineered Mutants for the Detection of Organophosphorus Pesticide Residues
Sensors 2018, 18(12), 4281; https://doi.org/10.3390/s18124281 - 05 Dec 2018
Cited by 10 | Viewed by 1643
Abstract
Nowadays, pesticide residues constitute an increasing public health concern. Cholinesterases, acetylcholinesterase, and butyrylcholinesterase, are reported to be involved in detoxification processes owing to their capability of scavenging organophosphates and carbamates. Thus, these enzymes are targeted for the discovery of sensors aiming at detecting [...] Read more.
Nowadays, pesticide residues constitute an increasing public health concern. Cholinesterases, acetylcholinesterase, and butyrylcholinesterase, are reported to be involved in detoxification processes owing to their capability of scavenging organophosphates and carbamates. Thus, these enzymes are targeted for the discovery of sensors aiming at detecting pesticide residues. In recent years, cholinesterase-based biosensors have attracted more and more attention in the detection of pesticides. Herein, this review describes the recent progress on the engineering of cholinesterases and the development of the corresponding sensors that could be used for the detection of organophosphorus pesticide residues. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Review
Application of Gold-Nanoparticle Colorimetric Sensing to Rapid Food Safety Screening
Sensors 2018, 18(12), 4166; https://doi.org/10.3390/s18124166 - 27 Nov 2018
Cited by 35 | Viewed by 2906
Abstract
Due to their unique optical properties, narrow size distributions, and good biological affinity, gold nanoparticles have been widely applied in sensing analysis, catalytic, environmental monitoring, and disease therapy. The color of a gold nanoparticle solution and its maximum characteristic absorption wavelength will change [...] Read more.
Due to their unique optical properties, narrow size distributions, and good biological affinity, gold nanoparticles have been widely applied in sensing analysis, catalytic, environmental monitoring, and disease therapy. The color of a gold nanoparticle solution and its maximum characteristic absorption wavelength will change with the particle size and inter-particle spacing. These properties are often used in the detection of hazardous chemicals, such as pesticide residues, heavy metals, banned additives, and biotoxins, in food. Because the gold nanoparticles-colorimetric sensing strategy is simple, quick, and sensitive, this method has extensive applications in real-time on-site monitoring and rapid testing of food quality and safety. Herein, we review the preparation methods, functional modification, photochemical properties, and applications of gold nanoparticle sensors in rapid testing. In addition, we elaborate on the colorimetric sensing mechanisms. Finally, we discuss the advantages and disadvantages of colorimetric sensors based on gold nanoparticles, and directions for future development. Full article
(This article belongs to the Special Issue Colorimetric and Fluorescent Sensors 2018)
Show Figures

Figure 1

Back to TopTop