Search Results (151)

Non-enzymatic glucose sensing has attracted considerable interest as a promising alternative to enzyme-based sensors, addressing limitations such as poor stability and high cost. To overcome the challenges of expensive noble metals and the inherent issues of pure copper oxide (CuO), including low conductivity and aggregation tendency, this study developed a composite sensing material based on two-dimensional CuO nanosheets decorated with gold nanoparticles (Au NPs). A series of Au/CuO nanocomposites with varying Au loadings were synthesized through a combined hydrothermal and in situ reduction approach. Systematic electrochemical characterization revealed that the composite with 7.41 wt% Au loading exhibited optimal sensing performance, achieving sensitivities of 394.29 and 257.14 μA·mM⁻¹·cm⁻² across dual linear ranges of 5–3550 μM and 4550–11,550 μM, respectively, with a detection limit of 10 μM and a rapid response time of 3 s. The sensor also demonstrated selectivity against common interferents as well as long-term stability. This work highlights the importance of precise noble metal loading control in optimizing sensor performance and offers a feasible material design strategy for developing high-performance non-enzymatic glucose sensors. Full article

The global rise in diabetes has intensified the demand for advanced glucose monitoring technologies that provide continuous, accurate, and real-time detection. Traditional sensing approaches often face challenges related to sensitivity, long-term stability, and suitability for wearable or implantable systems. In this context, titanium dioxide (TiO₂) nanotube arrays (NTAs) have emerged as a versatile platform owing to their well-defined nanostructure, tunable surface properties, and semiconductor nature, which collectively enable enhanced performance across different sensing modes. These include enzymatic systems, non-enzymatic configurations, and photoelectrochemical (PEC) sensors. While each sensing strategy offers considerable potential, certain inherent limitations continue to be explored. Ongoing research is gradually uncovering various pathways to enhance performance and reliability through the introduction of novel materials and system designs. Looking forward, the broader integration of TiO₂-based sensing platforms with evolving technological frameworks may contribute to the advancement of more adaptive and user-friendly glucose monitoring solutions. Full article

The rapid development of nanotechnology has significantly transformed the design and performance of glucose biosensors, leading to enhanced sensitivity, selectivity, and real-time monitoring capabilities. This review highlights recent advances in glucose-sensing platforms facilitated by nanomaterials, including metal and metal oxide nanoparticles, carbon-based nanostructures, two-dimensional materials, and metal–organic frameworks (MOFs). The integration of these nanoscale materials into electrochemical, optical, and wearable biosensors has addressed longstanding challenges associated with enzyme stability, detection limits, and invasiveness. Special emphasis is placed on non-enzymatic glucose sensors, flexible and wearable devices, and hybrid nanocomposite systems. The multifunctional properties of nanomaterials, such as large surface area, excellent conductivity, and biocompatibility, have enabled the development of next-generation sensors for clinical, point-of-care, and personal healthcare applications. The review also discusses emerging trends such as biodegradable nanosensors, AI-integrated platforms, and smart textiles, which are poised to drive the future of glucose monitoring toward more sustainable and personalized healthcare solutions. Full article

The development of multifunctional nanostructured catalysts with high electrochemical activity and stability is crucial for sustainable technologies. Herein, we report the synthesis of CTAB-capped NiCo₂O₄ (CNC) spinel nanostructures via a facile co-precipitation method, engineered to enhance surface activity and charge transport. The optical and structural properties of the nanocomposite were confirmed by UV-Vis and TEM analysis, and the functional group present in the composite was confirmed by FT-IR study. The cubic spinel phase of the CNC was confirmed by XRD analysis. The band gap value was determined to be 2.15 eV, which confirmed the semiconductor nature of the nanocomposite. The photocatalytic degradation efficiency was achieved up to approximately 97% against malachite green. Additionally, CNC demonstrated excellent electrocatalytic performance in non-enzymatic glucose detection, exhibiting high sensitivity and reproducibility across a broad concentration range. Hence, the CNC acted as a potent oxidant for photoelectrochemical reactions. Full article

Three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates have demonstrated remarkable abilities of ultrasensitive and reproducible molecular detection. The combination of both electromagnetic and chemical enhancement processes, light trapping, and multiple scattering effects of 3D structures are what enhance their performance. The principles of underlying enhancements are summarized systematically, and the main types of 3D substrates—vertically aligned nanowires, dendritic and fractal nanostructures, porous frameworks and aerogels, core–shell and hollow nanospheres, and hierarchical hybrid structures—are categorized in this review. Advances in fabrication techniques, such as template-assisted growth, electrochemical and galvanic deposition, dealloying and freeze-drying, self-assembly, and hybrid integration, are critically evaluated in terms of structural tunability and scalability. Novel developments in the field of biosensing are also highlighted, including non-enzymatic glucose sensing, tumor biomarker sensing, and drug delivery. The remaining limitations, such as low reproducibility, mechanical stability, and substrate standardization, are also noted, and future directions, such as stimuli-responsive designs, multifunctional hybrid platforms, and data-driven optimization strategies of SERS technologies, are also included. Full article

This work describes a non-enzymatic electrochemical glucose biosensor combining for the first time molecularly imprinted polymers (MIPs) for glucose concentration and gold nanoparticles (AuNPs) on screen-printed carbon electrodes (SPEs), where both MIPs and AuNPs were assembled in situ. Electrochemical impedance spectroscopy (EIS) was used to evaluate the analytical performance of the sensor, which has a linear range between 1.0 µM and 1.0 mM when standard solutions are prepared in buffer. Direct measurement of glucose was performed by chronoamperometry, measuring the oxidation current generated during direct glucose oxidation. The selectivity was tested against ascorbic acid and the results confirmed a selective discrimination of the electrode for glucose. Overall, the work presented here represents a promising tool for tracking glucose levels in serum. The use of glucose MIP on the electrode surface allows the concentration of glucose, resulting in lower detection limits, and the use of AuNPs reduces the potential required for the oxidation of glucose, which increases selectivity. In addition, this possible combination of two analytical measurements following different theoretical concepts can contribute to the accuracy of the analytical measurements. This combination can also be extended to other biomolecules that can be electrochemically oxidised at lower potentials. Full article

The detection of glucose concentration has a wide range of applications and plays a significant role in the fields of the food industry, medical health, and illness diagnostics. The utilization of sensor technology for glucose concentration detection is an effective approach. Glucose sensors utilizing nanomaterials, with high sensitivity, strong resistance to interference, and compact size, exhibit tremendous potential in glucose concentration detection. Traditional enzyme-based sensors exhibit superior selectivity and high sensitivity; however, they are deficient in terms of interference resistance capabilities. With the development of nanotechnology, the performance of glucose sensors has been significantly improved. This review discusses the research progress in non-enzymatic electrochemical glucose nanosensors, including noble metal-based glucose sensors and non-noble transition metal compound-based glucose sensors, as well as the applications of multimetallic materials in nanosensors. Additionally, the application of nanosensors based on fluorescence and colorimetric principles in the detection of glucose concentration is introduced in this review. Finally, a perspective on the challenges and prospects of nanosensors in the field of glucose detection is presented. Full article

Films of a Ni/Al-layered double hydroxide intercalated with reduced graphene oxide were deposited, by means of a simple and rapid electrochemical synthesis, on Pt electrodes previously submitted to a special cleaning procedure. The aim of the research was to determine whether the better electrocatalytic properties of the Ni(III)/Ni(II) couple, due to the presence of the carbon nanomaterial, as compared to the Ni/Al-LDH alone, could allow glucose detection at physiological pHs, as normally LDHs work as redox mediators in basic solutions. Chronoamperometric experiments were carried out by applying a potential of 1.0 V vs. SCE to the electrode soaked in solutions buffered at pHs from 5.0 to 9.0 to which glucose was continuously added. The steady-state currents increased as the pH solution increased, but at pH = 7.0 the modified electrode exhibited a fast and rather sensitive response, which was linear up to 10.0 mM glucose, with a sensitivity of 0.56 A M⁻¹ cm⁻² and a limit of detection of 0.05 mM. Our results suggest the potential application of Ni/Al-LDH(ERGO) composite for the non-enzymatic detection of glucose or other oxidizable analytes under biological conditions. Full article

The increasing prevalence of diabetes mellitus necessitates the development of advanced glucose-monitoring systems that are non-invasive, reliable, and capable of real-time analysis. Wearable electrochemical biosensors have emerged as promising tools for continuous glucose monitoring (CGM), particularly through sweat-based platforms. This review highlights recent advancements in enzymatic and non-enzymatic wearable biosensors, with a specific focus on the pivotal role of nanomaterials in enhancing sensor performance. In enzymatic sensors, nanomaterials serve as high-surface-area supports for glucose oxidase (GOx) immobilization and facilitate direct electron transfer (DET), thereby improving sensitivity, selectivity, and miniaturization. Meanwhile, non-enzymatic sensors leverage metal and metal oxide nanostructures as catalytic sites to mimic enzymatic activity, offering improved stability and durability. Both categories benefit from the integration of carbon-based materials, metal nanoparticles, conductive polymers, and hybrid composites, enabling the development of flexible, skin-compatible biosensing systems with wireless communication capabilities. The review critically evaluates sensor performance parameters, including sensitivity, limit of detection, and linear range. Finally, current limitations and future perspectives are discussed. These include the development of multifunctional sensors, closed-loop therapeutic systems, and strategies for enhancing the stability and cost-efficiency of biosensors for broader clinical adoption. Full article

Background: N^ε-(carboxymethyl)-lysine (CML) is formed in the human body by non-enzymatically driven reactions including glycation, oxidation, and lipoxidation. CML is a ubiquitous product of normal physiology, but its levels are increased under disease conditions like chronic kidney disease (CKD) and diabetes mellitus (DM). Free CML is eliminated from the human body mainly through kidney excretion, and its accumulation in the kidney tissue is linked to CKD pathogenesis. Aim: The main goal of this study was to evaluate the relative contribution of CKD and Type 2 DM (T2DM) to the accumulation of CML in patients’ sera. Methods: The study included 22 patients with CKD without DM, 55 with CKD and comorbid T2DM, and 21 with T2DM without CKD. Serum CML levels were measured by ELISA. The Kruskal-Wallis test was used to detect differences among groups. Spearman correlation analysis was performed, and the one-tailed Dunn test was considered to indicate statistical significance at p < 0.05. Results: The median serum CML levels (CKD, 658.4 ± 434.3 ng/mL; CKD + T2DM, 431.3 ± 327.9 ng/mL; T2DM, 273.9 ± 134.2 ng/mL) differed significantly (p < 0.05) among the three patient groups. A positive correlation was observed between serum CML and microalbuminuria (p = 0.004; r = 0.58), proteinuria (p = 0.002; r = 0.6), and age (p = 0.007; r = 0.52) only in the CKD patients. In all T2DM patients, independent of CKD status, serum CML correlated negatively (p < 0.05) with postprandial glucose and duration of diabetes, while its correlation with fasting glucose and HbA1c was negative only in the T2DM cohort without CKD. Conclusions: In patients with CKD, higher levels of CML were observed compared to those with T2DM. Serum CML correlated positively with proteinuria, albuminuria, and patient age in non-diabetic CKD patients, and negatively with blood glucose, HbA1c, and DM duration of T2DM in patients without CKD. Full article

In this study, a simple, mild, and eco-friendly cold plasma-solution interaction method is employed to rapidly prepare gold colloids. Through modification with multi-walled carbon nanotubes (MWCNTs), a non-enzymatic glucose-sensing electrode material is successfully fabricated. The prepared electrode material is characterized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results show that compared with the chemically reduced AuNPs-C-MWCNTs, the plasma-prepared AuNPs-P-MWCNTs exhibits enhanced glucose catalytic performance with a higher sensitivity of 73 μA·mM⁻¹·cm⁻² (approximately 3.2 times that of AuNPs-C-MWCNTs), lower response time of 2.1 s, and ultra-low detection limit of 0.21 μM. It also demonstrates excellent selectivity, reproducibility (RSD = 4.37%), repeatability (RSD = 3.67%), and operational stability (RSD = 4.51%). This improvement can be attributed to the smaller particle size and better dispersion of plasma-derived AuNPs on the surface of MWCNTs. Furthermore, the AuNPs-P-MWCNTs surface is enriched with oxygen-containing functional groups, which is conducive to the enhancement of the hydrophilicity of the electrode surface. These synergistic effects facilitate the AuNPs-catalyzed glucose oxidation reaction, ultimately leading to superior glucose catalytic performance. Full article

Bioactive compounds have shown significant potential in the management of obesity and metabolic syndrome (MetS). This study investigates the effects of antioxidant lipids (ALω-3), synthetized through enzymatic acidolysis using non-specific lipase B from Candida antarctica under supercritical CO₂ conditions. These lipids were derived from a concentrate of rainbow trout (Oncorhynchus mykiss) belly oil, rich in long-chain polyunsaturated omega-3 fatty acids (LCPUFAn-3), and cold-pressed maqui seed oil (MO, Aristotelia chilensis (Mol.) Stuntz). Their effects were then evaluated in a murine high-fat diet (HFD) model. The fatty acid profile, tocopherol and tocotrienol content, and thin-layer chromatography of ALω-3 were analyzed. After 8 weeks on an HFD, male C57BL/6 mice were divided into four groups and switched to a control diet (CD) with the following supplements for 3 weeks: Glycerol (G), commercial marine Omega-3 (CMω-3), a mixture of LCPUFAn-3 concentrate + MO (Mω-3), or ALω-3. The total body and organ weights, serum markers, and liver and visceral fat pro-inflammatory marker expression levels were assessed. ALω-3 contained 13.4% oleic, 33.9% linoleic, 6.3% α-linolenic, 10.7% eicosapentaenoic, and 16.2% docosahexaenoic fatty acids. The β, γ, δ-tocopherol, and β, γ-tocotrienol values were 22.9 ± 1.4, 24.9 ± 0.2, 6.8 ± 0.7, 22.9 ± 1.7, and 22.4 ± 4.7 mg·kg⁻¹, respectively, with α-tocopherol detected in traces. ALω-3 supplementation increased serum Trolox equivalent capacity, significantly reduced serum GPT levels (p < 0.01), and enhanced postprandial glucose tolerance (p < 0.001), although it did not alter insulin resistance (HOMA-IR). These findings indicate ALω-3′s potential for mitigating the glucose intolerance, liver damage, and oxidative stress associated with obesity and MetS, highlighting the need for additional research to explore its potential health benefits. Full article

Single-phase ternary Mn-Cu-Al alloy ribbons were fabricated by melt-spinning a Mn₄₈Cu₂₈Al₂₄ ingot on a rotating copper roller. They were used as dealloying precursor for forming the nanoporous structure in HCl solution. The basic dealloying behavior was examined by controlling the dealloying time from 5 min to 180 min at 50 °C. Due to the active chemical property, Mn and Al elements are easily etched in acid solutions. Meanwhile, Cu elements retained and rearranged. A three-dimensional bicontinous nanoporous structure was fabricated, with a ligament size of 55 nm~100 nm and pore size of 35 nm~85 nm. The porosity evolution of dealloyed MnCuAl alloy was divided into three stages. First, the dissolution of Mn and Al is so significant that formation of pores is dominant. Stage two, the rapid growth of both ligament size and pore size. The ligament/pore ratio is nearly unchanged. The last stage is ligament coarsening. Moreover, the electrocatalytic activity for glucose oxidation of dealloyed samples is examined. The 40 min dealloyed MnCuAl ribbon exhibited the highest sensitivity and relatively maximum current density. Full article

We are reporting the development of a high-performance, non-enzymatic electrochemical biosensor for selective lactate detection, integrating laser-induced graphene (LIG), gold nanoparticles (AuNPs), and a molecularly imprinted polymer (MIP) synthesized from poly(3,4-ethylenedioxythiophene) (PEDOT). The LIG electrode offers a highly porous, conductive scaffold, while electrodeposited AuNPs enhance catalytic activity and signal amplification. The PEDOT-based MIP layer, electropolymerized via cyclic voltammetry, imparts molecular specificity by creating lactate-specific binding sites. Cyclic voltammetry confirmed successful molecular imprinting and enhanced interfacial electron transfer. The resulting LIG/AuNPs/MIP biosensor demonstrated a wide linear detection range from 0.1 µM to 2500 µM, with a sensitivity of 22.42 µA/log(µM) and a low limit of detection (0.035 µM). The sensor showed excellent selectivity against common electroactive interferents such as glucose and uric acid, long-term stability, and accurate recovery in artificial saliva (>95.7%), indicating strong potential for practical application. This enzyme-free platform offers a robust and scalable strategy for continuous lactate monitoring, particularly suited for wearable devices in sports performance monitoring and critical care diagnostics. Full article

The demand for sustainable, low-cost bioprocesses has encouraged the development of alternative enzyme production strategies. This study investigated the purification and characterization of a crude enzymatic extract (CEE) rich in α-amylase from Coprinus comatus, using wheat milling by-products as substrate. The CEE was obtained by submerged culture, followed by biomass removal, centrifugation, and ultrafiltration to yield a partially purified enzyme (PE). CEE and PE were evaluated for chemical composition, antioxidant and antibacterial activity, toxicity (Artemia salina assay), and enzymatic performance. Toxicity assays confirmed that CEE was non-toxic. Antioxidant activity reached 213.34 µmol TE·gDE⁻¹ (DPPH assay), with a total phenolic content of 8.01 mg GAE·gDE⁻¹. No antibacterial activity was detected. CEE hydrolyzed 96.31% of starch in 180 min, releasing 10.85 g·L⁻¹ glucose, while PE achieved 98% hydrolysis and released 14.5 g·L⁻¹. Optimal α-amylase activity occurred at 50 °C and pH 5.5 (CEE) or 5.0 (PE). Calcium ions improved the enzymatic activity and thermal stability. CEE retained over 60% activity after 721 days under refrigeration (4 °C) or freezing (0 °C). Although lyophilization enhanced enzyme concentration, it increased production costs. SDS-PAGE revealed bands of ~67 kDa (α-amylase) and ~35 kDa (glucoamylase). These findings support the use of CEE as a sustainable, low-cost biocatalyst for industrial use. Full article