Recent progress of personal glucose meters integrated methods in food safety hazards detection

An electrochemical aptasensor for zearalenone detection based on the Co3O4/MoS2/Au nanocomposites and hybrid chain reaction

An electrochemical aptasensor was used for the fast and sensitive detection of zearalenone (ZEN) based on the combination of Co3O4/MoS2/Au nanocomposites and the hybrid chain reaction (HCR). The glassy carbon electrode was coated with Co3O4/MoS2/Au nanomaterials to immobilize the ZEN-cDNA that had been bound with ZEN-Apt by the principle of base complementary pairing. In the absence of ZEN, the HCR could not be triggered because the ZEN-cDNA could not be exposed. After ZEN was added to the surface of the electrode, a complex structure was produced on the modified electrode by the combination of ZEN and ZEN-Apt. Therefore, the ZEN-cDNA can raise the HCR to produce the long-strand dsDNA structure. Due to the formation of dsDNA, the methylene blue (MB) could be inserted into the superstructure of branched DNA and the peak currents of the MB redox signal dramatically increased. So the concentration of ZEN could be detected by the change of signal intensity. Under optimized conditions, the developed electrochemical biosensing strategy showed an outstanding linear detection range of 1.0×10-10 mol/L to 1.0×10-6 mol/L, a low detection limit (LOD) of 8.5×10-11 mol/L with desirable selectivity and stability. Therefore, the fabricated platform possessed a great application potential in fields of food safety, medical detection, and drug analysis.

Recent Advances in Personal Glucose Meter-Based Biosensors for Food Safety Hazard Detection

Food safety has emerged as a significant concern for global public health and sustainable development. The development of analytical tools capable of rapidly, conveniently, and sensitively detecting food safety hazards is imperative. Over the past few decades, personal glucose meters (PGMs), characterized by their rapid response, low cost, and high degree of commercialization, have served as portable signal output devices extensively utilized in the construction of biosensors. This paper provides a comprehensive overview of the mechanism underlying the construction of PGM-based biosensors, which consists of three fundamental components: recognition, signal transduction, and signal output. It also detailedly enumerates available recognition and signal transduction elements, and their modes of integration. Then, a multitude of instances is examined to present the latest advancements in the application of PGMs in food safety detection, including targets such as pathogenic bacteria, mycotoxins, agricultural and veterinary drug residues, heavy metal ions, and illegal additives. Finally, the challenges and prospects of PGM-based biosensors are highlighted, aiming to offer valuable references for the iterative refinement of detection techniques and provide a comprehensive framework and inspiration for further investigations.

Recent Progress in Screening of Mycotoxins in Foods and Other Commodities Using MXenes-Based Nanomaterials

Mycotoxin pollution in agricultural food products endangers animal and human health during the supply chains, therefore the development of accurate and rapid techniques for the determination of mycotoxins is of great importance for food safety guarantee. MXenes-based nanoprobes have attracted enormous attention as a complementary analysis and promising alternative strategies to conventional diagnostic methods, because of their fascinating features, like high electrical conductivity, various surface functional groups, high surface area, superb thermal resistance, good hydrophilicity, and environmentally-friendlier characteristics. In this study, we outline the state-of-the-art research on MXenes-based probes in detecting various mycotoxins like aflatoxin, ochratoxin, deoxynivalenol, zearalenone, and other toxins as a most commonly founded mycotoxin in the agri-food supply chain. First, we present the diverse synthesis approaches and exceptional characteristics of MXenes. Afterward, based on the detecting mechanism, we divide the biosensing utilizations of MXenes into two subcategories: electrochemical, and optical biosensors. Then their performance in effective sensing of mycotoxins is comprehensively deliberated. Finally, present challenges and prospective opportunities for MXenes are debated.

Advanced biosensors for mycotoxin detection incorporating miniaturized meters

Advanced biosensors, considered as emerging technologies, are capable of accurate, quantitative and real-time analysis for point-of-care testing (POCT) applications. Moreover, the integrating of miniaturized meters into these advanced biosensors makes them ideally appropriate for portable, sensitive and selective detection of biomolecules. Miniaturized meters including PGMs (personal glucose meters), thermometer, pressuremeter, pH meter, etc. are the most accurate devices and wide availability in the market, exhibiting a promising potential towards detection of small molecule mycotoxins. In this article, we introduce and analyze the recent advancements for sensing of mycotoxins measured by handheld meters since the first report in 2012. Furthermore, limitations and challenges for versatile meters application against mycotoxins in food matrix are highlighted. By overcoming the bottleneck problems, we believe the miniaturized meters-based biosensor platform will provide great possibilities for mycotoxins analysis and launch them to the market.

Carbon Nanotube-Based Biosensors Using Fusion Technologies with Biologicals & Chemicals for Food Assessment

High-sensitivity sensors applied in various diagnostic systems are considered to be a promising technology in the era of the fourth industrial revolution. Biosensors that can quickly detect the presence and concentration of specific biomaterials are receiving research attention owing to the breakthroughs in detection technology. In particular, the latest technologies involving the miniaturization of biosensors using nanomaterials, such as nanowires, carbon nanotubes, and nanometals, have been widely studied. Nano-sized biosensors applied in food assessment and in in vivo measurements have the advantages of rapid diagnosis, high sensitivity and selectivity. Nanomaterial-based biosensors are inexpensive and can be applied to various fields. In the present society, where people are paying attention to health and wellness, high-technology food assessment is becoming essential as the consumer demand for healthy food increases. Thus, biosensor technology is required in the food and medical fields. Carbon nanotubes (CNTs) are widely studied for use in electrochemical biosensors. The sensitive electrical characteristics of CNTs allow them to act as electron transfer mediators in electrochemical biosensors. CNT-based biosensors require novel technologies for immobilizing CNTs on electrodes, such as silicon wafers, to use as biosensor templates. CNT-based electrochemical biosensors that serve as field-effect transistors (FET) increase sensitivity. In this review, we critically discuss the recent advances in CNT-based electrochemical biosensors applied with various receptors (antibodies, DNA fragments, and other nanomaterials) for food evaluation, including pathogens, food allergens, and other food-based substances.

A Catechol-Meter Based on Conventional Personal Glucose Meter for Portable Detection of Tyrosinase and Sodium Benzoate

In this study, the personal glucose meter (PGM) was first used as a fast and user-friendly meter for analyzing catechol (CA) based on the reduction of the mediator K₃[Fe(CN)₆] to K₄[Fe(CN)₆] in the glucose test strip. Then, an easy, low-cost, and convenient PGM-based method for detecting tyrosinase (TYR) activity and sodium benzoate (SBA) was developed on the basis of the TYR-catalyzed reaction. In this method, CA is oxidized to form o-benzoquinone by TYR, thereby reducing the residual amount of CA and the PGM readout. On the other hand, SBA can inhibit the oxidation of CA catalyzed by TYR and increase the residual amount of CA after the enzymatic reaction. Therefore, the activity of TYR is proportional to the difference in the PGM readout of CA, and the concentration of SBA is positively correlated with the residual amount of CA. After the relevant experimental conditions were systematically optimized, the proposed PGM-based method for the detection of TYR and SBA was successfully validated. The liner ranges are 1.0-103.3 U/mL and 6.25-1000 ppm, and the quantification limits are 1.0 U/mL and 6.25 ppm for TYR and SBA, respectively. Moreover, the spiked recovery tests in normal human serum and carbonate beverages (i.e., Cola, Sprite, and Fanta) were performed, and the recoveries (91.6-106.8%) further confirm the applicability of the PGM-based method in real sample analysis.

Nanochannel Array on Electrochemically Polarized Screen Printed Carbon Electrode for Rapid and Sensitive Electrochemical Determination of Clozapine in Human Whole Blood

Rapid and highly sensitive determination of clozapine (CLZ), a psychotropic drug for the treatment of refractory schizophrenia, in patients is of great significance to reduce the risk of disease recurrence. However, direct electroanalysis of CLZ in human whole blood remains a great challenge owing to the remarkable fouling that occurs in a complex matrix. In this work, a miniaturized, integrated, disposable electrochemical sensing platform based on the integration of nanochannel arrays on the surface of screen-printed carbon electrodes (SPCE) is demonstrated. The device achieves high determination sensitivity while also offering the electrode anti-fouling and anti-interference capabilities. To enhance the electrochemical performance of SPCE, simple electrochemical polarization including anodic oxidation and cathodic reduction is applied to pretreat SPCE. The electrochemically polarized SPCE (p-SPCE) exhibits an enhanced electrochemical peak signal toward CLZ compared with bare SPCE. An electrochemically assisted self-assembly method (EASA) is utilized to conveniently electrodeposit a vertically ordered mesoporous silica nanomembrane film (VMSF) on the p-SPCE, which could further enrich CLZ through electrostatic interactions. Owing to the dual signal amplification based on the p-SPCE and VMSF nanochannels, the developed VMSF/SPCE sensor enables determination of CLZ in the range from 50 nM to 20 μM with a low limit of detection (LOD) of 28 nM (S/N = 3). Combined with the excellent anti-fouling and anti-interference abilities of VMSF, direct and sensitive determination of CLZ in human blood is also achieved.

Portable quantification of silver ion by using personal glucose meter (PGM) and magnetite cross-linked invertase aggregates (MCLIA)

Heavy metal detection is critical due to its harmful effects on human health and the ecosystem. Enzyme-based platforms attract attention for heavy metal detection such as silver, a toxic metal, due to being small, portable, and requiring only essential equipment compared with the basic analytical methods. In this study, magnetic cross-linked invertase aggregates (MCLIA) were developed for the first time as an enzyme-based signaling platform to detect Ag⁺ using a personal glucose meter (PGM). EDX, FTIR, and VSM results depicted that MCLIA was successfully developed and exhibits super-paramagnetism. In addition, MCLIA selectively detected the Ag⁺ at a sensitivity of 1.2 inhibition rate/μM in a linear range from 5 to 70 μM with a detection limit of 4.6 μM and IC₅₀ value of 42.3 μM. These findings strongly indicate that MCLIA is applicable as a signal platform for portable quantification of other analytes that inhibits the invertase enzyme.