Recent advances in nanomaterial‐assisted electrochemical sensors for food safety analysis

Development of an electrochemical sensor utilizing MWCNs-poly(2-aminothiophenol) @AgNPs nanocomposite for the simultaneous determination of Pb2+ and Cd2+ in food samples

This study focuses on the synthesis and characterization of the Multiwall Carbon Nanotubes-Poly(2-aminothiophenol) @silver nanoparticles nanocomposite (MWCNTs-PATP@AgNPs) using different analytical methods. The synthesized MWCNTs-PATP@AgNPs served as an electrocatalytic modifier, enabling the highly selective and sensitive detection of Pb2+ and Cd2+ ions at nanomolar levels using square wave anodic stripping voltammetry. The concentration of MWCNTs- PATP @AgNPs, the type and concentration of the electrolyte, the solution's pH, and the preconcentration conditions, were systematically optimized. A linear response was observed for Pb2+ and Cd2+ within the ranges of 0.5-60.0 nmolL-1 and 8.0-50.0 nmol L-1, respectively, with detection limits of 0.125 nmol L-1 for Pb2+ and 1.47 nmol L-1 for Cd2+. Furthermore, the MWCNTs-PATP@AgNPs sensor demonstrated the capability to selectively detect these target metals in the presence of various common interfering species. The sensor was effectively utilized for the detection of Pb2+ and Cd2+ ions across various real samples.

A Cost-Effective and Rapid Manufacturing Approach for Electrochemical Transducers with Magnetic Beads for Biosensing

Biosensors as advanced analytical tools have found various applications in food safety, healthcare, and environmental monitoring in rapid and specific detection of target analytes in small liquid samples. Up to now, planar electrochemical electrodes have shown the highest potential for biosensor applications due to their simple and compact construction and cost-effectiveness. Although a number of commercially available electrodes, manufactured from various materials on different substrates, can be found on the market, their high costs for single use and low reproducibility persist as major drawbacks. In this study, we present an innovative, cost-effective approach for the rapid fabrication of electrodes that combines lamination of 24-karat gold leaves with low-cost polyvinyl chloride adhesive sheets followed by laser ablation. Laser ablation enables the creation of electrodes with customizable geometries and patterns with microlevel resolutions. The developed electrodes are characterized by cyclic voltammetry and electrochemical impedance spectroscopy, scanning electronic microscopy, and 3D profiling. To demonstrate the manufacturing and biosensing potential, different geometries and shapes of electrodes were realized as the electrochemical transducing platform and applied for the realization of magnetic bead (MB)-labeled biosensors for quantitative detection of food-borne pathogens of Salmonella typhimurium (S. typhimurium) and Listeria monocytogenes (L. monocytogenes).

Nanobody-Based Immunoassays for the Detection of Food Hazards-A Review

Food safety remains a significant global challenge that affects human health. Various hazards, including microbiological and chemical threats, can compromise food safety throughout the supply chain. To address food safety issues and ensure public health, it is necessary to adopt rapid, accurate, and highly specific detection methods. Immunoassays are considered to be an effective method for the detection of highly sensitive biochemical indicators and provide an efficient platform for the identification of food hazards. In immunoassays, antibodies function as the primary recognition elements. Nanobodies have significant potential as valuable biomolecules in diagnostic applications. Their distinctive physicochemical and structural characteristics make them excellent candidates for the development of reliable diagnostic assays, and as promising alternatives to monoclonal and polyclonal antibodies. Herein, we summarize a comprehensive overview of the status and prospects of nanobody-based immunoassays in ensuring food safety. First, we begin with a historical perspective on the development of nanobodies and their unique characteristics. Subsequently, we explore the definitions and boundaries of immunoassays and immunosensors, before discussing the potential applications of nanobody-based immunoassays in food safety testing that have emerged over the past five years, and follow the different immunoassays, highlighting their advantages over traditional detection methods. Finally, the directions and challenges of nanobody-based immunoassays in food safety are discussed. Due to their remarkable sensitivity, specificity and versatility, nanobody-based immunoassays hold great promise in revolutionizing food safety testing and ensuring public health and well-being.

A HOF-101@AgNPs-based dual-signal mode aptasensor for electrochemiluminescence and fluorescence detection of E. coli O157:H7

Escherichia coli O157:H7 (E. coli O157:H7) emerges as a foodborne pathogen, emphasizing the imperative for creating precise detection tools. An ultrasensitive electrochemiluminescence/fluorescence (ECL/FL) dual-signal mode aptasensor was constructed for the detection of E. coli O157:H7. Ultrafine silver nanoparticles were loaded on the surface of hydrogen-bonded organic skeleton materials by in-situ photoreduction method, and then combined with aptamers that can identify specific targets to prepare HOF-101@AgNPs@Apt, greatly simplifying the ECL/FL dual-signal mode probe fabrication process and improving sensing reliability. HOF-101@AgNPs@Apt had both strong ECL luminescence and fluorescence, resulting in a high detection sensitivity. The low limit of detection (LOD) for ECL and FL were 0.48 CFU mL-1 and 2.39 CFU mL-1, respectively. Moreover, the proposed dual-signal mode aptasensor has been successfully applied to determine E. coli O157:H7 levels in tap water and milk with superior accuracy and high antiinterference capability, providing a promising method for food safety monitoring.

PULSE: A Fast Portable Unit for Lab-on-Site Electrochemistry

This study aims to develop and validate a novel fast-detection electrochemical sensing platform to enhance portable electrochemical sensor solutions. The research focuses on optimising analogue front-end circuits, developing data analysis algorithms, and validating the device through experiments to enhance measurement accuracy and detection speed, enabling on-site measurements across diverse applications. This work successfully designed a Portable Unit for Lab-on-Site Electrochemistry (PULSE) system with dimensions of (78×100×2) mm3. The device's implementation was complemented by robust firmware that performed desired electrochemical measurements, including open circuit potentiometry (OCP), chronoamperometry (CA), and cyclic voltammetry (CV). To assess its reliability, the PULSE was benchmarked against a well-established benchtop potentiostat. The results obtained highlight the system's rapid sensing capabilities, achieving pH detection in 2 s and performing CA in 20 s. The pH calibration curve exhibited Nernstian behaviour with an accuracy of 97.58%. A correlation analysis comparing the calibration curve datasets across all electrochemical techniques from both systems revealed high correlation coefficients (>0.99), confirming the strong agreement between the two systems.

An antifouling electrochemical sensor based on a U-shaped four-in-one peptide and poly(3,4-ethylenedioxythiophene) for vancomycin detection in fresh goat milk

Nonspecific adsorption of biomolecules (notably, proteins) and bacteria from unsterilized food may occur on sensor surfaces, which is still a challenge for food safety sensing. To achieve sensitive detection of unsterilized raw-food materials, in this study, a U-shaped four-in-one peptide with the sequence Ac-FLKLLKKLL-DOPA3-PPPPEEKDQDKEKaa that exhibited anchoring, antifouling, antibacterial, and recognition properties was designed. The peptide-modified sensor surface effectively prevented bacterial adhesion and proliferation while resisting biomolecule adsorption (signal inhibition rate as low as 0.51 % in single-protein solutions). A highly conductive polymer layer of poly(3,4-ethylenedioxythiophene) was introduced to improve the electrochemical performance before U-shaped four-in-one peptide anchoring. The proposed sensor could accurately detect vancomycin, with a wide linear range and limit of detection of 0.05-10 μg mL-1 and 2.06 ng mL-1 (S/N = 3), respectively. Satisfactory recovery rates (101.3-105.3 %) were achieved using diluted fresh goat milk.

Liquid-Solid Triboelectric Nanogenerator-Based DNA Barcode Detection Biosensor for Species Identification

DNA barcode detection method is widely applied for species identification, which is imperative to evaluate the effect of human economic activities on the biodiversity of ecosystem. However, the wide utilization of existing detection biosensors is limited by bulky and expensive instruments, such as Raman spectroscopy and electrochemical station. Herein, a liquid-solid triboelectric nanogenerator (TENG)-based DNA barcode detection biosensor is proposed, which consists of water flow, fluid channel, and PDMS film attached by specifically designed capture probe. Through sequentially combining capture probe, targeted DNA barcode, and signal probe with Au nanoparticles (NPs), the surface charge density of friction layer of TENG decreases under the effect of AuNPs, verified by the density functional theory (DFT) method. Consequently, the peak value of output current spike signal for targeted DNA is smaller than that for other DNA, which is the working mechanism of the present TENG-based biosensor. Such biosensor successfully recognizes Alvinocaris muricola among different types of Alvinocarididae shrimps, and its low limit detection can reach 1×10-12 m. The present work provides a paradigm-shift way to develop an inexpensive and accurate technique to detect DNA barcode for species identification, and paves a novel way for the application of liquid-solid TENG.

Advancements in electrochemical sensingTechnology for Heavy Metal Ions Detection

Most heavy metal ions are carcinogenic and non-biodegradable, posing threats to ecological balance and human health in trace amount. Therefore, there is a pressing demand for rapid and dependable detection technologies. Electrochemical sensing technology distinguishes itself with its ease of use and swiftness, rendering it perfect for the expeditious detection of heavy metal elements. This review examines various electrochemical detection techniques for on-site real-time monitoring of heavy metal ions. Advanced methods using innovative electrochemical sensor technologies are explored, highlighting the importance of sensing strategies for the quick and easy monitoring of metal levels in different environments. Additionally, the role of nanotechnology and electrochemical techniques in enhancing the sensitivity and selectivity of sensors for better detection of heavy metals is discussed. Finally, the future direction of sensor development is addressed, focusing on integrating new materials and technologies to improve the performance of sensor in environmental monitoring, food safety and public health.

Electrochemical study of an enhanced platform by electrochemical synthesis of three-dimensional polyaniline nanofibers/reduced graphene oxide thin films for diverse applications

This work reports the electrochemical fabrication of thin films comprising polyaniline nanofibers (PANI) in conjunction with graphene oxide (GO) and reduced graphene oxide (rGO) on ITO substrate, along with examining the electrochemical properties, with a focus on the influence of the substrate and electrolyte in the electrodeposition methods. The study explores the electrochemical characteristics of these thin films and establishes a flexible framework for their application in diverse sectors such as sensors, supercapacitors, and electronic devices. It analyzes the impact of the substrate and electrolyte in electrodeposition techniques. The effects were studied using techniques such as cyclic voltammetry and chronoamperometry. The fabrication process of PANI/GO and PANI/rGO thin films involved the integration of rGO within PANI via electropolymerization, conducted under sulfuric acid. GO was synthesized by modifying the well-known Hummers' method and characterized by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SEM showed the diameters of the formed PANI were between 40 and 150 nm, which helped to intertwine the rGO nanosheets with PANI nanofibers to form thin films. The electrochemical behavior of the PANI/rGO thin films was examined using cyclic voltammetry (CV) and chronoamperometry in different electrolytes, including sulfuric acid (H₂SO₄) and potassium nitrate (KNO₃). The CV profiles exhibited distinct oxidation and reduction peaks, with variations in the voltammogram morphology attributed to the nature of the electrolyte and the substrate employed during the electrodeposition process. These results highlight the critical role of both the substrate and electrolyte in governing the electrochemical performance of PANI/rGO thin films. The findings from this study demonstrate a versatile approach for the fabrication of PANI/graphene-based thin films with tunable electrochemical properties, and such a strategy has great application to fabricating other thin film composites for supercapacitors or other control source frameworks requiring enhanced charge storage and electrochemical responsiveness.

Recent advances in ratiometric electrochemical sensors for food analysis

Ratiometric electrochemical sensors are renowned for their dual-signal processing capabilities, enabling automatic correction of background noise and interferences through built-in calibration, thus providing more accurate and reproducible measurements. This characteristic makes them highly promising for food analysis. This review comprehensively summarizes and discusses the latest advancements in ratiometric electrochemical sensors and their applications in food analysis, emphasizing their design strategies, detection capabilities, and practical uses. Initially, we explore the construction and design strategies of these sensors. We then review the detection of various food-related analytes, including nutrients, additives, metal ions, pharmaceutical and pesticide residues, biotoxins, and pathogens. The review also briefly explores the challenges faced by ratiometric electrochemical sensors in food testing and potential future directions for development. It aims to provide researchers with a clear introduction and serve as a reference for the design and application of new, efficient ratiometric electrochemical sensors in food analysis.

Flower-Shaped PCR Scaffold-Based Lateral Flow Bioassay for Bacillus cereus Endospores Detection

Bacillus cereus, a foodborne pathogen, produces resilient endospores that are challenging to detect with conventional methods. This study presents a novel Flower-Shaped PCR Scaffold-based Lateral Flow Biosensor (FSPCRS-LFB), which employs an aptamer-integrated PCR scaffold as capture probes, replacing the traditional streptavidin-biotin (SA-Bio) approach. The FSPCRS-LFB demonstrates high sensitivity and cost-efficiency in detecting B. cereus endospores, with a limit of detection (LOD) of 4.57 endospores/mL a visual LOD of 102 endospores/mL, and a LOD of 6.78 CFU/mL for endospore-cell mixtures. In chicken and tea samples, the platform achieved LODs of 74.5 and 52.8 endospores/mL, respectively, with recovery rates of 82.19% to 97.88%. Compared to existing methods, the FSPCRS-LFB offers a 3.7-fold increase in sensitivity while reducing costs by 26% over the SA-Bio strategy and 87.5% over rolling circle amplification (RCA). This biosensor provides a rapid, sensitive and cost-effective solution for point-of-care testing (POCT) of B. cereus endospores, expanding detection capabilities and offering novel approaches for pathogen detection.

Preparation of amphiphilic polyquaternium nanofiber films with antibacterial activity via environmentally friendly microfluidic-blow-spinning for green food packaging applications

Green food packaging plays an important role in environmental protection and sustainable development. Therefore, it is advisable to employ low-energy consumption manufacturing techniques, select environmentally friendly materials, and focus on cost-effectiveness with high production yields during the production process. In this study, an amphiphilic polyquaternium called PBzCl was proposed and synthesized by free radical polymerization of cost-efficient quaternary ammonium salts and methacrylate monomers. Then, biodegradable PCL and PVP were used to rapidly prepare the PBzCl@PCL/PVP nanofiber films via environmentally friendly microfluidic-blow-spinning (MBS). The best antibacterial effect was observed at a PBzCl loading concentration of 13.5%, and the PBzCl@PCL/PVP nanofiber films had 91% and 100% antibacterial rates against Escherichia coli and Staphylococcus aureus, respectively. Besides, the loading of PBzCl improved the water stability of the PCL/PVP nanofiber films, and the films also showed excellent biocompatibility. Overall, PBzCl@PCL/PVP nanofibre films have promising food packaging potential.

Self-powered molecularly imprinted photoelectrochemical sensor based on Ppy/QD/HOF heterojunction for the detection of bisphenol A

As an emerging porous material, hydrogen-bonded organic framework materials (HOFs) still pose application challenges. In this work, the designed type "I + II" heterojunction extracted hot electrons from HOFs using quantum dots (QDs) and polypyrrole (Ppy), improving the stability and photoelectrochemical performance of materials. In addition to serving as a potential well, electropolymerized Ppy was used as a recognition element for bisphenol A (BPA), and a novel self-powered molecularly imprinted photoelectrochemical (MIP-PEC) sensor was designed. The sensing platform showed a linear relationship from 1 × 10-10 to 1 × 10-7 mol∙L-1 and from 1 × 10-7 to 1 mol∙L-1 with an acceptable detection limit of 4.2 × 10-11 mol∙L-1. This is the first application of HOFs in constructing MIP-PEC sensors and a new attempt to improve the stability of HOFs for the application of porous crystal materials in the sensing field.

Structure of plasmonic multi spectral Apta sensor and analyzing of bulk and surface sensitivity

In this work, a multispectral aptasensor structure, including a sub-layer and two side walls, was presented. The cells are positioned at the down and top of the structure, with the down cells oriented perpendicular to the walls and the top cells aligned parallel to the walls. The validity of the findings was verified by the utilization of a numerical simulation technique known as 3D Finite Difference Time Domain (FDTD). The biosensor under consideration exhibits sensitivities of 1093.7 nm/RIU, 754 nm/RIU, and 707.43 nm/RIU in mode III, mode II, and mode I, respectively. In the majority of instances, the quantity of analyte available is insufficient to coat the surface of the sensor thoroughly. Consequently, in this study, the evaluation of surface sensitivity was undertaken alongside bulk sensitivity. The surface sensitivity of the suggested structure for mode II in the sensor layer, with thicknesses of 10, 20, 30, and 70 nm, is measured to be 25, 78, 344, and 717.636 nm/RIU, respectively. Our design incorporates a unique arrangement of sub-layer and side walls, with cells positioned to maximize interaction with the target analyte. This innovative configuration, combined with Ag for its superior plasmonic properties, enables the detection of E. coli O157 with remarkable sensitivity.

Deep eutectic solvent-assisted synthesis of La-Ce hybrid nanorods for the colorimetric determination of tetracycline in foods

Tetracycline (TC) as a broad-spectrum antibiotic, is widely used in the prevention and treatment of various bacterial diseases. However, its abuse in the livestock industry may lead to interference in human microecology, thereby causing various side effects. In this study, deep eutectic solvents (DESs) were synthesized using L-(-)-threonine (L-(-)-Thr) and cerium nitrate hexahydrate (Ce(NO3)3·6H2O), and later lanthanum nitrate hexahydrate (La(NO3)3·6H2O) was doped to synthesize La-Ce hybrid nanorods. These nanorods can be used for the determination of TC with high sensitivity and selectivity by the colorimetric method. This approach has a linear response to TC between 0.05 μM and 10 μM, with a detection limit of 0.016 μM. In this system, good dispersion provides the substance with a distinct peroxidase activity, which is used to create a colorimetric sensor for detecting TC. Mechanism studies show that the superoxide radical generated by the La-Ce nanomembrane plays a key role in peroxidase catalysis. Finally, the practicality of the method was verified by the determination of TC in food products (milk, pork and honey), which demonstrated that a good recovery rate can be obtained (91.4-102%).

Detection of luteolin in food using a novel electrochemical sensor based on cobalt-doped microporous/mesoporous carbon encapsulated peanut-like FeOx composite

Luteolin (Lu) is a dietary flavonoid that has attracted much attention due to its multiple health benefis effects. Herein, an ultrasensitive electrochemical sensor for Lu was constracted based on cobalt-doped microporous/mesoporous carbon (MMC) encapsulated peanut-like Fe2O3 composite. The FeOx-Co-MMC composite was obtained by pyrolyzing a precursor named Fe2O3-Co-microporous/mesoporous dopamine (Fe2O3-Co-MMPDA) which was synthesized by a soft template method. Under optimized conditions, the sensor exhibited good detection of Lu with a low limit of detection (LOD) of 0.031 nM and a wide linear range from 0.05 to 1000 nM in detecting Lu. It also demonstrated good reproducibility (RSD = 3.16%), stability (RSD = 2.34%), and anti-interference properties. The sensor successfully detected Lu in real food samples such as honeysuckle with recoveries ranging from 96.1% to 104.8% (RSD <3%, n = 3). The present study provides an alternative method for Lu detection in food.

Two birds with one stone: A universal design and application of signal-on labeled fluorescent/electrochemical dual-signal mode biosensor for the detection of tetracycline residues in tap water, milk and chicken

An ingenious and universal design of fluorescent/electrochemical dual-signal mode sensing platform was constructed for the sensitive, selective and accurate detection of tetracycline (TET). Apt-functionalized nano-magnetic beads (Fe3O4-Apt) as capture probe, Apt-complementary short-chain functionalized fluorescent MOF loaded with methylene blue (MB) (cDNA-MOF-MB) as dual-signal tag were prepared. The sensing platform (Fe3O4-Apt/cDNA-MOF-MB) was formed based on the base complementary pairing of Apt and cDNA. With the help of Apt for target recognition, together with magnetic separation technology, a dual-signal mode biosensor was constructed. The dual-signal mode biosensor exhibited a wide linear concentration range from 1.00 × 10-9 g/mL to 1.00 × 10-4 g/mL with a low limit of detection (LOD) of 1.69 × 10-10 g/mL (fluorescence mode assay) and 1.15 × 10-10 g/mL (electrochemical mode assay). The proposed biosensor had been successfully applied to the determination of TET content in real samples with satisfactory recoveries (94.99-101.30%).

Engineering an Antifouling Electrochemical Sensing Platform Based on an All-in-One Peptide and a Hierarchical β-Bi2O3-Au Microsphere for Vancomycin Detection in Food

Challenges associated with interference aroused by nonspecific attachment of foulants in the food matrix steered the development of sensor surfaces capable of antifouling capacity. In this study, an antifouling electrochemical sensing platform based on an all-in-one peptide (DOPA3-PPPPEKDQDKKaa) with anchoring, antifouling, and recognition functions and a hierarchical β-Bi2O3-Au microsphere was proposed for vancomycin (Van) detection in food. The β-Bi2O3-Au with excellent conductivity was synthesized and introduced as an electrode modifier to accelerate electron transfer on the sensor surface, enhancing sensing response. Mussel organism-inspired oligo DOPA, that is, oligo 3,4-dihydroxyphenylalanine, was employed as the anchoring segment of the all-in-one peptide, which is versatile for surfaces with different materials. PPPPEKDQDK and Kaa as antifouling and recognition segments confer abilities to resist nonspecific adsorption of foulants and specifically bind Van on the sensor surface, respectively. Notably, the excellent antifouling performance of the proposed sensor has been verified in protein solutions, carbohydrate solutions, and even in diluted milk and honey. Molecular dynamics simulation was carried out to explain the antifouling mechanism of the all-in-one peptide. The proposed sensor can detect Van sensitively and selectively with a relatively wide linear range (0.1-100 ng mL-1) and a limit of detection (LOD) as low as 0.038 ng mL-1 and support the quantification of Van in milk, milk powder, and honey samples with satisfactory recoveries within 105.3-110.8%. This antifouling electrochemical sensing platform offers a feasible strategy to reduce matrix interference, which guarantees the accurate detection of Van in food samples.

Environmental endocrine disruptors and pregnane X receptor action: A review

The pregnane X receptor (PXR) is a kind of orphan nuclear receptor activated by a series of ligands. Environmental endocrine disruptors (EEDs) are a wide class of molecules present in the environment that are suspected to have adverse effects on the endocrine system by interfering with the synthesis, transport, degradation, or action of endogenous hormones. Since EEDs may modulate human/rodent PXR, this review aims to summarize EEDs as PXR modulators, including agonists and antagonists. The modular structure of PXR is also described, interestingly, the pharmacology of PXR have been confirmed to vary among different species. Furthermore, PXR play a key role in the regulation of endocrine function. Endocrine disruption of EEDs via PXR and its related pathways are systematically summarized. In brief, this review may provide a way to understand the roles of EEDs in interaction with the nuclear receptors (such as PXR) and the related pathways.

Chemical antifouling strategies in sensors for food analysis: A review

Surface biofouling induced by the undesired nonspecific adsorption of foulants (e.g., coexisting proteins and cells) in food matrices is a major issue of sensors for food analysis, hindering their reliability and accuracy of sensing. This issue can be addressed by developing antifouling strategies to prevent or alleviate nonspecific binding. Chemical antifouling strategies involve the use of chemical modifiers (i.e., antifouling materials) to strongly hydrate the surface and reduce surface biofouling. Through appropriate immobilization approaches, antifouling materials can be tethered onto sensors to form antifouling surfaces with well-ordered structures, balanced surface charges, and appropriate surface density and thickness. A rational antifouling surface can reduce the matrix effect, simplify sample pretreatment, and improve analytical performance. This review summarizes recent developments in chemical antifouling strategies in sensing. Surface antifouling mechanisms and common antifouling materials are described, and factors that may influence the antifouling effects of antifouling surfaces and approaches incorporating antifouling materials onto sensing surfaces are highlighted. Moreover, the specific applications of antifouling sensors in food analysis are introduced. Finally, we provide an outlook on future developments in antifouling sensors for food analysis.

An ultrasensitive dietary caffeic acid electrochemical sensor based on Pd-Ru bimetal catalyst doped nano sponge-like carbon

Caffeic acid (CA) is widely present in the human daily diet, and a reliable CA detection method is beneficial to food safety. Herein, we constructed a CA electrochemical sensor employing a glassy carbon electrode (GCE) which was modified by the bimetallic Pd-Ru nanoparticles decorated N-doped spongy porous carbon obtained by pyrolysis of the energetic metal-organic framework (MET). The high-energy bond N-NN in MET explodes to form N-doped sponge-like carbon materials (N-SCs) with porous structures, boosting the adsorptive capacity for CA. The addition of Pd-Ru bimetal improves the electrochemical sensitivity. The linear range of the PdRu/N-SCs/GCE sensor is 1 nM-100 nM and 100 nM-15 μM, with a low detection limit (LOD) of 0.19 nM. It has a high sensitivity (55 μA/μM) and repeatability. The PdRu/N-SCs/GCE sensor has been used to detect CA in actual samples of red wine, strawberries, and blueberries, providing a novel approach for CA detection in food analysis.

Cu2+ assisted carnation-like fluorescent metal-organic framework for triple-mode detection of glyphosate in food samples

Herein, by employing a novel synthesized ligand H₂L, a flower-like luminescent metal-organic framework IRMOF-3-L was constructed for developing a triple-mode sensor for glyphosate (Glyp) detection. The ligand H₂L was designed to contain three functional parts, which endowed the resulted IRMOF-3-L with peroxidase-like activity and unique fluorescence property, as well as specific combining capacity for Cu²⁺ to quench its fluorescence. The quenched fluorescence of IRMOF-3-L/Cu²⁺ could be recovered by Glyp to realize fluorescence detection of Glyp. Besides, the peroxidase activity of IRMOF-3-L/Cu²⁺ could also be inhibited by Glyp, and result in the decrease of catalysate oxTMB, concurrently reducing the changes of colorimetric and SERS signal. Therefore, the fluorescent/colorimetric/SERS triple-mode based detection of Glyp was favorably realized, and the detection limits were calculated as low as 0.738, 2.26 and 0.186 nM, respectively. Furthermore, a portable test strips-smartphone sensing platform was constructed for point of care testing of Glyp in food samples.

Novel Sensitive Electrochemical Immunosensor Development for the Selective Detection of HopQ H. pylori Bacteria Biomarker

Helicobacter pylori (H. pylori) is a highly contagious pathogenic bacterium that can cause gastrointestinal ulcers and may gradually lead to gastric cancer. H. pylori expresses the outer membrane HopQ protein at the earliest stages of infection. Therefore, HopQ is a highly reliable candidate as a biomarker for H. pylori detection in saliva samples. In this work, an H. pylori immunosensor is based on detecting HopQ as an H. pylori biomarker in saliva. The immunosensor was developed by surface modification of screen-printed carbon electrodes (SPCE) with MWCNT-COOH decorated with gold nanoparticles (AuNP) followed by HopQ capture antibody grafting on SPCE/MWCNT/AuNP surface using EDC/S-NHS chemistry. The sensor performance was investigated utilizing various methods, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). H. pylori detection performance in spiked saliva samples was evaluated by square wave voltammetry (SWV). The sensor is suitable for HopQ detection with excellent sensitivity and linearity in the 10 pg/mL-100 ng/mL range, with a 2.0 pg/mL limit of detection (LOD) and an 8.6 pg/mL limit of quantification (LOQ). The sensor was tested in saliva at 10 ng/mL, and recovery of 107.6% was obtained by SWV. From Hill's model, the dissociation constant Kd for HopQ/HopQ antibody interaction is estimated to be 4.60 × 10^-10 mg/mL. The fabricated platform shows high selectivity, good stability, reproducibility, and cost-effectiveness for H. pylori early detection due to the proper choice of biomarker, the nanocomposite material utilization to boost the SPCE electrical performance, and the intrinsic selectivity of the antibody-antigen approach. Additionally, we provide insight into possible future aspects that researchers are recommended to focus on.

Review on Sensor Array-Based Analytical Technologies for Quality Control of Food and Beverages

Food quality control is an important area to address, as it directly impacts the health of the whole population. To evaluate the food authenticity and quality, the organoleptic feature of the food aroma is very important, such that the composition of volatile organic compounds (VOC) is unique in each aroma, providing a basis to predict the food quality. Different types of analytical approaches have been used to assess the VOC biomarkers and other parameters in the food. The conventional approaches are based on targeted analyses using chromatography and spectroscopies coupled with chemometrics, which are highly sensitive, selective, and accurate to predict food authenticity, ageing, and geographical origin. However, these methods require passive sampling, are expensive, time-consuming, and lack real-time measurements. Alternately, gas sensor-based devices, such as the electronic nose (e-nose), bring a potential solution for the existing limitations of conventional methods, offering a real-time and cheaper point-of-care analysis of food quality assessment. Currently, research advancement in this field involves mainly metal oxide semiconductor-based chemiresistive gas sensors, which are highly sensitive, partially selective, have a short response time, and utilize diverse pattern recognition methods for the classification and identification of biomarkers. Further research interests are emerging in the use of organic nanomaterials in e-noses, which are cheaper and operable at room temperature.

Advances in microbial analysis: based on volatile organic compounds of microorganisms in food

In recent years, microbial volatile organic compounds (mVOCs) produced by microbial metabolism have attracted more and more attention because they can be used to detect food early contamination and flaws. So far, many analytical methods have been reported for the determination of mVOCs in food, but few integrated review articles discussing these methods are published. Consequently, mVOCs as indicators of food microbiological contamination and their generation mechanism including carbohydrate, amino acid, and fatty acid metabolism are introduced. Meanwhile, a detailed summary of the mVOCs sampling methods such as headspace, purge trap, solid phase microextraction, and needle trap is presented, and a systematic and critical review of the analytical methods (ion mobility spectrometry, electronic nose, biosensor, and so on) of mVOCs and their application in the detection of food microbial contamination is highlighted. Finally, the future concepts that can help improve the detection of food mVOCs are prospected.

Recent advances in the biosynthesis, bioavailability, toxicology, pharmacology, and controlled release of citrus neohesperidin

Neohesperidin (hesperetin 7-O-neohesperidoside), a well-known flavanone glycoside widely found in citrus fruits, exhibits a variety of biological activities, with potential applications ranging from food ingredients to therapeutics. The purpose of this manuscript is to provide a comprehensive overview of the chemical, biosynthesis, and pharmacokinetics profiles of neohesperidin, as well as the therapeutic effects and mechanisms of neohesperidin against potential diseases. This literature review covers a wide range of pharmacological responses elicited by Neohesperidin, including neuroprotective, anti-inflammatory, antidiabetic, antimicrobial, and anticancer activities, with a focus on the mechanisms of those pharmacological responses. Additionally, the mechanistic pathways underlying the compound's osteoporosis, antiulcer, cardioprotective, and hepatoprotective effects have been outlined. This review includes detailed illustrations of the biosynthesis, biopharmacokinetics, toxicology, and controlled release of neohesperidine. Neohesperidin demonstrated a broad range of therapeutic and biological activities in the treatment of a variety of complex disorders, including neurodegenerative, hepato-cardiac, cancer, diabetes, obesity, infectious, allergic, and inflammatory diseases. Neohesperidin is a promising therapeutic candidate for the management of various etiologically complex diseases. However, further in vivo and in vitro studies on mechanistic potential are required before clinical trials to confirm the safety, bioavailability, and toxicity profiles of neohesperidin.

Recent Progress in Nanotechnology-Based Approaches for Food Monitoring

Throughout the food supply chain, including production, storage, and distribution, food can be contaminated by harmful chemicals and microorganisms, resulting in a severe threat to human health. In recent years, the rapid advancement and development of nanotechnology proposed revolutionary solutions to solve several problems in scientific and industrial areas, including food monitoring. Nanotechnology can be incorporated into chemical and biological sensors to improve analytical performance, such as response time, sensitivity, selectivity, reliability, and accuracy. Based on the characteristics of the contaminants and the detection methods, nanotechnology can be applied in different ways in order to improve conventional techniques. Nanomaterials such as nanoparticles, nanorods, nanosheets, nanocomposites, nanotubes, and nanowires provide various functions for the immobilization and labeling of contaminants in electrochemical and optical detection. This review summarizes the recent advances in nanotechnology for detecting chemical and biological contaminations in the food supply chain.

Point-of-care CRISPR/Cas biosensing technology: A promising tool for preventing the possible COVID-19 resurgence caused by contaminated cold-chain food and packaging

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused great public health concern and has been a global threat due to its high transmissibility and morbidity. Although the SARS-CoV-2 transmission mainly relies on the person-to-person route through the respiratory droplets, the possible transmission through the contaminated cold-chain food and packaging to humans has raised widespread concerns. This review discussed the possibility of SARS-CoV-2 transmission via the contaminated cold-chain food and packaging by tracing the occurrence, the survival of SARS-CoV-2 in the contaminated cold-chain food and packaging, as well as the transmission and outbreaks related to the contaminated cold-chain food and packaging. Rapid, accurate, and reliable diagnostics of SARS-CoV-2 is of great importance for preventing and controlling the COVID-19 resurgence. Therefore, we summarized the recent advances on the emerging clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system-based biosensing technology that is promising and powerful for preventing the possible COVID-19 resurgence caused by the contaminated cold-chain food and packaging during the COVID-19 pandemic, including CRISPR/Cas system-based biosensors and their integration with portable devices (e.g., smartphone, lateral flow assays, microfluidic chips, and nanopores). Impressively, this review not only provided an insight on the possibility of SARS-CoV-2 transmission through the food supply chain, but also proposed the future opportunities and challenges on the development of CRISPR/Cas system-based detection methods for the diagnosis of SARS-CoV-2.

Determination of luteolin in Chrysanthemum tea with a ultra-sensitive electrochemical sensor based on MoO3/poly(3,4-ethylene dioxythiophene)/gama-cyclodextrin metal-organic framework composites

Chrysanthemum tea is a tranditional Chinese health drink, which contains luteolin, a flavonoid with vesatile health benefit activities. Herein, A sensitive electrochemical sensor based on composite materials consisting of MoO₃ nanorods, poly (3, 4-ethylene dioxyethiophene)(PEDOT), and γ-cyclodextrin metal-organic framework(CD-MOF) was prepared.The materials were characterized and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). Due to the synergisticeffects of the materials, the sensor showed a wide linear range of 0.4 nM -1800 nM and a low detection limit (LOD) of 0.1 nM (S/N = 3) for luteolin under optimized conditions. Besides, the influences of some coexistent phenolic compounds and common metal ions on luteolin detection were evaluated and no significant interference was observed. Finally, the sensor was successfully applied to the detection of luteolin in real Chrysanthemum tea samples.

A strategy for reducing acrylamide content in wheat bread by combining acidification rate and prerequisite substance content of Lactobacillus and Saccharomyces cerevisiae

This study mainly focused on a strategy for reducing acrylamide(AM) content in wheat breads by combining Lactobacilli and Saccharomyces cerevisiae in sourdough, in comparison with natural fermentation. The results showed that acrylamide levels in breads using sourdough were much lower (102.02-129.37 μg/kg) than control group (204.79 μg/kg). The pH value of sourdough directly influenced the formation of acrylamide in breads (P < 0.01). Furthermore, significant (P < 0.05) correlations were also found between protein and acrylamide contents. There no significant correlations were observed between acrylamide and reducing sugar contents. According to the different effects of strains, it could be concluded that the acrylamide reducing potential of strains was strain-specific, with Pediococcus pentosaceus being the most effective. This suggests that sourdough fermentation with appropriate strains can be used as an advantageous technology to reduce the acrylamide content of wheat breads.