Food Safety Monitoring Research Articles

A practical fluorometric and colorimetric dual-mode sensing platform based on two-dimensional porous organic nanosheets for rapid determination of trifluralin.

Trifluralin, a widely used dinitroaniline herbicide, poses significant toxic risks, necessitating the development of rapid detection methods for food safety. In this study, we prepared ultrathin two-dimensional triphenylamine porous organic nanosheets (TPA-PONs) through a facile liquid-phase exfoliation process. The TPA-PONs, characterized by their exceptional fluorescence properties and nanoscale thickness (1.65 ± 0.3 nm), demonstrated a remarkable fluorescence quenching response upon exposure to trifluralin. Spectroscopic analysis combined with DFT calculations revealed that the quenching mechanism is driven by electron and energy transfer. TPA-PONs-based fluorescence sensor exhibited a linear response to trifluralin concentrations ranging from 0.01 to 10.0 μmol L-1 with a limit of detection as low as 3.50 nmol L-1. Additionally, the sensor was applied to detect trifluralin residues in vegetables, achieving recoveries of 89.08-102.84%. To facilitate on-site detection, a novel TPA-PONs-based colorimetric film sensor has been developed, enabling visual analysis of trifluralin using a smartphone. This dual-mode sensing platform holds significant potential for enhancing food safety monitoring.

Optimization of the Extraction Protocol for Pacific Ciguatoxins from Marine Products Prior to Analysis Using the Neuroblastoma Cell-Based Assay

Ciguatera poisoning (CP) is caused by the consumption of marine products contaminated with ciguatoxins (CTXs) produced by dinoflagellates of the genus Gambierdiscus. Analytical methods for CTXs, involving the extraction/purification of trace quantities of CTXs from complex matrices, are numerous in the literature. However, little information on their effectiveness for nonpolar CTXs is available, yet these congeners, contributing to the risk of CP, are required for the establishment of effective food safety monitoring programs. An evaluation of six extraction/purification protocols, performed with CTX3C spiked on fish flesh and a neuroblastoma cell-based assay (CBA-N2a), revealed recoveries from 6 to 45%. This led to the development of an optimized 3-day protocol designed for a large number of samples, with CTX1B and CTX3C eluting in a single fraction and showing recoveries of 73% and 70%, respectively. In addition, a reduction in adverse matrix effects in the CBA-N2a analyses was demonstrated with naturally contaminated specimens, increasing the sensitivity of the method, which now meets the very low guidance level recommended by international agencies. However, efforts are still required to reduce the signal suppression observed in LC-MS/MS analysis. This optimized protocol contributes to the technological advancement of detection methods, promoting food safety and improving CP risk assessment in marine products.

Integration of DNA-Decorated Hapten in Emergency Immunoassays for Antibody and Small-Molecule Detection: A Review.

DNA-decorated hapten (DDH)-based immunoassays have emerged, demonstrating supreme advantages in sensing applications because of their excellent sensitivity, specificity, and reliability. DDH combines both a recognition element (hapten) and a signal transduction element (DNA portion) with its highly programmable DNA structure enabling the trigger of signal transduction following a recognition event, thereby introducing a novel signal transduction mechanism to immunoassays. In this review, we provide a critical overview of recent research in the DDH-based immunoassays, which are designed to detect specific small molecules and antibodies. On the basis of the following events after binding of antibodies to DDH, the reported studies involved with DDH-based immunoassays can be categorized into three groups: (i) DDH-based immunoassay based on DNA conformational switches induced by antibody binding, (ii) DDH-based immunoassay based on co-localization of nucleic acids induced by antibody binding, and (iii) DDH-based immunoassay based on antibody steric hindrance. We also focus on several fundamental elements of DDH-based immunoassays, including the designed DNA structure, principles of signal transformation, and platform of DDH-based immunoassays. Then, the representative applications of DDH-based immunoassays in areas such as food safety, medical diagnostics, and environmental monitoring as well as the challenges and perspectives of DDH-based immunoassays are also explored.

Ultra-sensitive, on-site pesticide detection for environmental and food safety monitoring using flexible cellulose nano fiber/Au nanorod@Ag SERS sensor.

This paper introduces a highly absorbent and sensitive cellulose nanofiber (CNF)/gold nanorod (GNR)@Ag surface-enhanced Raman scattering (SERS) sensor, fabricated using the vacuum filtration method. By optimizing the Ag thickness in the GNR@Ag core-shell structures and integrating them with CNFs, optimal SERS hotspots were identified using the Raman probe molecule 4-aminothiophenol (4-ATP). To concentrate pesticides extracted from fruit and vegetable surfaces, we utilized the evaporation enrichment effect using hydrophilic CNF and hole-punched hydrophobic polydimethylsiloxane (PDMS). This design leverages the hydrophilic substrate and localized evaporation to create a microfluidic flow that concentrates analytes within a small hole area, enhancing SERS sensitivity by up to 465 %. The sensor achieved on-site detection limits for Thiram as low as 10-11 M on fruit surfaces, specifically apples and chili peppers. This approach underscores how localized molecule enrichment can substantially improve field-based pesticide analysis. the sensor's response to interfering substances (e.g., glucose and citric acid) and other harmful molecules (e.g., carbendazim and nitrofurazone was also evaluated, demonstrating high sensitivity and accuracy). The PDMS-assisted CNF/GNR@Ag SERS sensor exhibits flexibility, ease of fabrication, and excellent sensitivity and selectivity, showing significant potential for applications in food safety, agriculture, and environmental monitoring. These advancements are anticipated to promote the practical adoption of SERS-based sensor technology across diverse fields, suggesting broad future utility.

Portable foodborne pathogen detection via ratiometric fluorescence nanoprobe for adenosine triphosphate quantification based on DNA-functionalized metal-organic framework.

The increasing incidence of foodborne illnesses highlights the need for rapid, sensitive, and portable methods to detect pathogenic bacteria in food. In this work, we develop a portable method that utilizes a ratiometric fluorescence nanoprobe for adenosine triphosphate (ATP) quantification. The nanoprobe is constructed by encapsulating Ru(bpy)32+ within a zirconium-based metal-organic framework, followed by functionalization of double-stranded DNA (dsDNA). This design permits SYBR Green I (SGI) to intercalate into dsDNA, conferring the nanoprobe with dual-emission property. The presence of ATP disrupts dsDNA structure, quenching SGI fluorescence while maintaining Ru(bpy)32+ fluorescence, providing a stable reference signal. This differential response enables the nanoprobe to achieve ratiometric ATP detection with high precision and sensitivity, with a detection limit of 0.63μM. Since ATP is a reliable biomarker for viable bacterial cells, a portable hydrogel kit was further developed by integrating the ratiometric fluorescence nanoprobe into an agarose hydrogel matrix. The validation of the kit was conducted using a smartphone application for color recognition, enabling the rapid and on-site detection of pathogens in milk samples. The kit exhibits exceptional sensitivity with a detection limit of 10CFU/mL, making it a promising tool for real-time bacteria detection in food safety monitoring.

Patterns of belatacept use and risk of post-transplant lymphoproliferative disorder in US kidney transplant recipients: An analysis of the Organ Procurement and Transplantation Network database.

Belatacept is approved for the prophylaxis of organ rejection in Epstein-Barr virus (EBV)-seropositive kidney transplant recipients and is associated with a risk of post-transplant lymphoproliferative disorder (PTLD). Data from the Organ Procurement and Transplantation Network were used to examine patterns of belatacept use, describe patient characteristics, and estimate risk of PTLD in EBV-seropositive, kidney-only transplant recipients receiving belatacept- or calcineurin inhibitor (CNI)-based immunosuppression as part of US Food and Drug Administration-mandated safety monitoring. During the study period (June 15, 2011-June 14, 2016), 94.9% (1631/1719) of belatacept-treated and 89.7% (59,992/66,905) of CNI-treated patients with known EBV serostatus were EBV seropositive. Among EBV-seropositive patients, 50.2% (belatacept) and 56.8% (CNI) received a standard criteria donor kidney, 59.5% and 18.7% received basiliximab induction, and 22.9% and 50.8% received antithymocyte globulin induction. PTLD developed in nine belatacept-treated patients (two with central nervous system [CNS] involvement) and 225 CNI-treated patients (nine with CNS involvement). Four and 81 patients, respectively, died due to PTLD. Kaplan-Meier analysis did not show a significant between-group difference in PTLD estimated incidence rates within 5 years (0.70% versus 0.48%, respectively; p = 0.18). Additionally, estimated PTLD incidence was not significantly different between treatment groups in a propensity score matched cohort. The majority of adult kidney-only transplant recipients treated with belatacept in routine clinical practice are EBV seropositive. In this study, the risk of PTLD in these patients, while higher than for CNI-based immunosuppression, remained low after adjusting for differences in patient characteristics. These studies are registered at ClinicalTrials.gov: NCT01670058 and NCT01656343.

Species-specific mercury speciation in billfishes and its implications for food safety monitoring and dietary advice.

Humans are exposed to toxic methylmercury mainly by consuming marine fish, in particular top predator species like billfishes or tunas. In seafood risk assessments, mercury is assumed to be mostly present as organic methylmercury in predatory fishes; yet high percentages of inorganic mercury were recently reported in marlins, suggesting markedly different methylmercury metabolism across species. We quantified total mercury and methylmercury concentrations in muscle of four billfish species from the Indian and the Pacific oceans to address this knowledge gap. We found low percentages of methylmercury in blue and black marlins (15±7%) compared to swordfish and striped marlin (89±13%), with no significant differences among ocean regions. This illustrates that billfishes exhibit species-specific methylmercury bioaccumulation patterns, likely related to unique selenium-dependent in vivo methylmercury demethylation capacities in muscle. Blue and black marlins therefore appeared generally safer for human consumption than swordfish and striped marlin regarding MeHg toxicological effects. Yet, no matter the species, the frequency of recommended weekly billfish meals decreased with increasing fish size, given that mercury naturally accumulates over time. When assessing potential risks of billfish consumption, we therefore recommend measuring methylmercury, rather than total mercury, and relying on a large number of samples to cover a broad range of fish sizes. This study calls for additional characterization of mercury speciation and bioavailability in billfishes to better understand the mechanisms driving species-specific differences of methylmercury detoxification, and to refine dietary advices associated to marine top predators consumption.

Pressure Sensor Array Based on Four DNA-Nanoenzymes with Catalase-like Activity for Portable Multiple Detection of Foodborne Pathogens.

This study has developed a pressure sensor array based on four functionalized DNA-nanoenzymes with catalase-like activity for multiple detections of foodborne pathogens through a portable pressure manometer. Benefiting from functionalization of 4-mercaptophenylboronic acid and β-mercaptoethylamine, the diversity of nonspecific interactions between four DNA-nanoenzymes and each of the nine bacteria leads to differences in pressure response patterns by catalyzing H2O2 to generate exclusive "fingerprints". As effective statistical tools for processing multivariate data, principal component analysis and hierarchical clustering analysis are employed to identify nine foodborne pathogens by analyzing pressure response patterns. Furthermore, the as-prepared sensor array can discriminate different mixtures of bacteria and achieve quantitative detection, with an average detection limit of 102 and 104 CFU mL-1 for Gram-positive and Gram-negative bacteria, respectively, demonstrating its desirable practicality and satisfactory accuracy for real sample detection. This study expands insights into multiple analyses of foodborne pathogens for food safety monitoring.

Development of Sensitive R6G/AuNCs Ratiometric Fluorescent Probes for the Detection of Biogenic Amines in Fish Products.

Biogenic amines (BAs), produced in fish and seafood due to microbial contamination, pose significant health risks. This study introduces a novel ratiometric fluorescent probe, synthesized by integrating rhodamine 6G(R6G) and gold nanoparticles (AuNCs), for the sensitive and specific detection of BAs. The probe operates on the principle of BAs hydrolysis, catalyzed by diamine oxidase, to produce hydrogen peroxide (H2O2), which selectively quenches the fluorescence of AuNCs at 620 nm, while the fluorescence of R6Gat 533 nm remains unaffected. The ratio of I620/I553 demonstrated excellent linearity with a wide dynamic range (1-1000 μM) and a low detection limit of 0.1 μM. Validation using grass carp samples showed high recovery rates (97.57% to 104.29%), confirming the probe's efficacy and potential for practical application in food safety monitoring.

Enhanced Detection of Viable Escherichia coli O157:H7 in Romaine Lettuce Wash Water Using On-Filter Propidium Monoazide-Quantitative PCR

Accurate detection of viable Escherichia coli O157:H7 in fresh produce wash water is critical for ensuring food safety and mitigating foodborne illnesses. This study evaluated an optimized on-filter propidium monoazide (PMA)-quantitative PCR (qPCR) method for detecting viable E. coli O157:H7 in romaine lettuce wash water, involving PMA pretreatment on a filter to block DNA amplification from dead cells. The method consistently detected viable cells across chemical oxygen demand (COD) levels of 1000 and 200 mg O2/L, with no significant differences (p > 0.05), indicating its tolerance to organic matter interference. Optimization experiments identified 10 µM PMA with a 10 min exposure time as the most effective pretreatment, achieving efficient inhibition of DNA from dead cells while preserving viable cell integrity. The limit of detection (LOD) was 1.3 CFU/mL, confirming its suitability for detecting low bacterial loads. Performance evaluations revealed that PMA-qPCR was accurate at viable-to-dead cell ratios of 1:10 or higher but became less reliable when dead cells outnumbered viable cells by a factor of 10 or more. The study demonstrates the potential of on-filter PMA-qPCR for routine food safety monitoring protocols in the fresh produce industry, while highlighting the critical role of viable-to-dead cell ratios in ensuring accurate detection, particularly in challenging samples with high dead cell loads.

A Review of Nanotechnology Applications in Food Processing, Packaging, and Preservation

Nanotechnology has certainly become a phenomenon that is of great significance in many regions such as the pharmaceutical, cosmetic and in particular the food sector, over the years. This is because nanotechnology overlaps with pharmaceutical sciences which involve the structural modification of materials to the nano level, increasing the dissolution rate, stability, and functionality of a variety of food safety and quality applications. The novel food supply frameworks enable firms within the food sector to emerge sustainability focused innovations, which tackle safety and nutrition deficiencies within the food industry. Narrowing down on the supply chain, this review seeks to highlight nanotechnology applications across food supply chains, stressing the importance of advancements in bioavailability, nutrition, and safety. In aid of nutrient delivery, overcoming shelf life and packaging issues – development in nanoencapsulation technology and new packaging materials have enhanced mechanical properties, antibacterial properties. Moreover, nanodevice-based smart packaging is considered as valuable tools for real-time monitoring of food safety and quality. Despite these benefits, degenerative concerns about nanoparticles health risks underscore the importance of sound regulatory approaches. While nanotechnology shows considerable potential for enhancing food sustainability and quality, the study ultimately finds that comprehensive regulation and increased public awareness of potential risks are necessary first steps. Continued research and global collaboration may be vital to really unlock the potential of nanotechnology in food systems while safeguarding public health.

Triboelectric Nanogenerator Based on CPDs-WO3/MXene Bilayer Film for Triethylamine Sensing and Fish Meat Spoilage Detection.

With the increasing demand for food safety monitoring, the development of efficient, convenient, and green gas sensors has become a current research hotspot. Triboelectric nanogenerator (TENG) as a triethylamine sensor is a cutting-edge strategy for detection without the need for an additional power source. In this study, synthesized WO3/MXene materials were prepared and bilayer thin films of carbon quantum dots (CPDs)-WO3/MXene TENG. WO3 provides more active sites for improved material charge transfer efficiency. TENG achieved a maximum open-circuit voltage (Voc) of 30 V. The CPDs-WO3/MXene-3 TENG can also be used as a self-powered gas sensor (SPGS). As a charge-trapping layer, CPDs exhibit excellent charge trapping. The SPGS has a 53% response to 200 ppm TEA, and low detection at ppb level (139 ppb). The presence of WO3 improves the gas-sensing performance. Additionally, CPDs possess excellent conductivity and moisture resistance. Finally, it was studied to see how it reacts to TEA in fish meat under different conditions of spoilage. It provides approach to solving the transportation and preservation problems of fish meat.

Development and Application of a Multiplex Reverse Transcription–Droplet Digital PCR Assay for Simultaneous Detection of Hepatitis A Virus and Hepatitis E Virus in Bivalve Shellfish

Foodborne viruses are significant contributors to global food safety incidents, posing a serious burden on human health and food safety. In this study, a multiplex reverse transcription–droplet digital PCR (RT-ddPCR) assay based on the MS2 phage as a process control virus (PCV) was developed to achieve the simultaneous detection of hepatitis A virus (HAV) and hepatitis E virus (HEV) in bivalve shellfish. By optimizing the reaction system and procedures, the best reaction conditions were selected, and the specificity, sensitivity, and reproducibility of the method were assessed. Additionally, the MS2 phage’s recovery rate was utilized as an indicator to evaluate the optimal sample nucleic acid enrichment method. The results indicated that the RT-ddPCR assay exhibited optimal amplification efficiency with primer concentrations of 900 nmol/L, probe concentrations of 350 nmol/L for HAV and HEV, and 500 nmol/L for MS2, an annealing temperature of 53.1 °C, an extension time of 90 s, and 45 cycles. Additionally, the developed multiplex RT-ddPCR assay demonstrated high specificity, with quantitation limits of 12.6, 8.9, and 7.8 copies/reaction being observed for HAV, HEV, and the MS2 phage, respectively. A total of 240 bivalve samples were analyzed, of which 4 were positive for HAV and 12 for HEV. The viral loads for HAV ranged from 3048 to 6528 copies/2 g, while those for HEV ranged from 3312 to 20,350 copies/2 g. This assay provides a vital tool for enhancing food safety monitoring.

Origami-Inspired Biosensors: Exploring Diverse Applications and Techniques for Shape-Changing Sensor Platforms

Biosensors are widely used across industries such as healthcare, food safety, and environmental monitoring, offering high stability and sensitivity compared to conventional methods. Recently, origami—the art of folding 2D structures into 3D forms—has emerged as a valuable approach in biosensor development, enabling the creation of shape-changing devices. These origami-based biosensors are particularly useful in precision medicine, rapid diagnostics, and resource-limited settings, offering affordable, highly precise, and portable solutions with diverse applications. Paper and biological substrates like DNA have been integrated with origami techniques to develop biosensors with enhanced functionality. The incorporation of aptamer origami into both paper and DNA biosensors further increases sensitivity and specificity for target detection. The concept of paper-based origami biosensors originated from using paper as a platform for biological assays, leading to significant advancements in design and functionality. These devices employ folding techniques to create channels and wells for manipulating samples and detecting target molecules through reactions with specific reagents. Similarly, DNA origami, introduced in 2006, has revolutionized biosensors by enabling the creation of precise molecular systems with tunable properties. Paper-based and DNA origami biosensors have immense potential to transform biosensing technologies in healthcare, food safety, and environmental monitoring. This review explores diverse origami-based biosensor techniques and their applications, including the role of aptamer origami in paper and DNA biosensors.

Chromogenic Photonic Crystal Detectors for Monitoring Small Molecule Diffusion at Solid-Solid Interfaces Using Stimuli-Responsive Shape Memory Polymers.

In situ monitoring of small molecule diffusion at solid-solid interfaces is challenging, even with sophisticated equipment. Here, novel chromogenic photonic crystal detectors enabled by integrating bioinspired structural color with stimuli-responsive shape memory polymer (SMP) for detecting trace amounts of small molecule interfacial diffusion are reported. Colorless macroporous SMP membranes with deformed macropores can recover back to the "memorized" photonic crystal microstructures and the corresponding iridescent structural colors when triggered by diffused small molecules. Systematic experimental and theoretical investigations using various microscopes, optical spectroscopy and modeling, spatio-resolved energy-dispersive X-ray spectroscopy, and theoretical diffusion calculations confirm the diffusion-induced shape memory and chromogenic mechanisms. Importantly, proof-of-concept sensing of temporospatial-resolved diffusion of bioactive ingredients used in drug delivery, including anti-inflammatory methyl salicylate in pain relieving patches and vitamin E barriers loaded in contact lens, and phthalates plasticizers in commercial PVC products has been demonstrated. These innovative detectors are inexpensive, reusable, and easy to operate and deploy for both qualitative and quantitative analyses, promising for opening new avenues in biomedical research, threat detection, and monitoring of plastics, food, and environmental safety. Moreover, reconfigurable photonic crystals with micrometer-scale resolution, which are of great importance in tunable and integrated nanooptics, can be fabricated by diffusion-enabled microcontact printing.

Bacterial Communities and Their Role in Bacterial Infections.

Since infections associated with microbial communities threaten human health, research is increasingly focusing on the development of biofilms and strategies to combat them. Bacterial communities may include bacteria of one or several species. Therefore, examining all the microbes and identifying individual community bacteria responsible for the infectious process is important. Rapid and accurate detection of bacterial pathogens is paramount in healthcare, food safety, and environmental monitoring. Here, we analyze biofilm composition and describe the main groups of pathogens whose presence in a microbial community leads to infection (Staphylococcus aureus, Enterococcus spp., Cutibacterium spp., bacteria of the HACEK, etc.). Particular attention is paid to bacterial communities that can lead to the development of device-associated infections, damage, and disruption of the normal functioning of medical devices, such as cardiovascular implants, biliary stents, neurological, orthopedic, urological and penile implants, etc. Special consideration is given to tissue-located bacterial biofilms in the oral cavity, lungs and lower respiratory tract, upper respiratory tract, middle ear, cardiovascular system, skeletal system, wound surface, and urogenital system. We also describe methods used to analyze the bacterial composition in biofilms, such as microbiologically testing, staining, microcolony formation, cellular and extracellular biofilm components, and other methods. Finally, we present ways to reduce the incidence of biofilm-caused infections.

A Listeria monocytogenes aptasensor on laser inscribed graphene for food safety monitoring in hydroponic water

AbstractConsumption of fresh produce, such as leafy greens, is often encouraged as part of a healthy diet. Hence, indoor facilities for hydroponic production of leafy greens are increasingly being established. However, fresh produce entails a higher risk of microbial foodborne illnesses than processed foods. Listeria monocytogenes is a major source of fresh produce contamination and is among the leading causes of severe foodborne illnesses in the United States, with a 16% mortality rate. Tools for rapid monitoring are needed for pathogens such as L. monocytogenes to prevent outbreaks. In this manuscript, we have demonstrated the feasibility of a multi-aptamer approach for development of label-free aptasensors targeting L. monocytogenes in irrigation water for lettuce hydroponic production. We use screening studies with surface plasmon resonance to rationally develop mixtures of relevant aptamers for targeting L. monocytogenes. Based on this screening, multiple aptamers targeting extracellular structures on intact L. monocytogenes were tethered to platinum-modified laser inscribed graphene electrodes. This is the first report of a L. monocytogenes biosensor based on laser inscribed graphene. We show that mixing multiple aptamers with varying affinity improves the diagnostic performance over one aptamer alone in complex sample matrices (lettuce hydroponic water). Multi-aptamer biosensors showed high accuracy for L. monocytogenes and were at least three times more selective than Escherichia coli (Crooks, K12, O157:H7) with an accuracy of 85%. The limit of detection (10 CFU/10 mL) is based on data which were significantly different after calibration toward L. monocytogenes or E. coli (Crooks) and validated against gold standard molecular analysis (polymerase chain reaction). Rapid screening of pathogens is a global need to meet food safety and water quality regulations. This study shows the importance of sensors targeting more than one bacterial surface structure in complex samples relevant to the food-water nexus.

NANOTECHNOLOGY-ENABLED FOOD SAFETY: INNOVATIVE SOLUTIONS FOR AGRICULTURAL DEVELOPMENT, SMART PACKAGING, DELIVERY SYSTEMS, AND FOOD SECURITY

Nanotechnology is playing an important role to develop modern solutions in food safety and agriculture that make it highly efficient as well as safe. This paper is aimed at dissecting how nanotechnology can be used in smart packaging, delivery systems and food security in agriculture. Smart packaging instills such features like increased shelf life, food safety, and real-time monitoring of food quality when nanomaterials are incorporated into the packaging system. Hi-tech delivery systems made possible through nanotechnology improve the effectiveness of agrochemicals, minimize the adverse effects on the environment, and reclaim the principles of sustainable farming. In addition, nanotechnology helps to protect food from spoilage as well as enhance crop quality, yield, and pest resistance, and upgrade the nutritional value of foods. Combining the results of the current state of nanotechnology development and its future prospects, this paper recognizes nanotechnology as a powerful tool for the agricultural industry and a secure food supply chain.

Filter-assisted sample preparation for on-site detection using a bi-functional linker-based biosensor demonstrated with Escherichia coli O157:H7.

This study presents an advanced food detection platform that integrates filter-assisted sample preparation (FASP) with a bifunctional linker-based biosensor for on-site detection of Escherichia coli O157:H7 as a model case. FASP isolates bacteria from food samples through multi-filter preprocessing, significantly enhancing the specificity, sensitivity, and reproducibility of the subsequent biosensor analysis. This platform can detect E. coli O157:H7 at concentrations as low as 102CFU per 25g of tomato with a total processing time of 2.5h from sampling to testing using an on or off detection method. FASP supports large food processing volumes up to 250mL, maximizing bacterial capture and minimizing microbial loss during pre-treatment. This integrated approach significantly improves the speed, accuracy, and practicality of pathogen detection, offering a robust solution for onsite microbial detection and enhancing food safety monitoring in the food industry.

Quantitative fluorescent detection of tetracycline in animal-derived foods using quantum dots

Tetracycline (Tc) antibiotics, a class of synthetically produced broad-spectrum antimicrobial drugs, have been widely used in animal husbandry, leading to their widespread presence in animal-derived foods. However, misuse, overuse, and non-compliance with withdrawal periods in animal farming have resulted in excessive Tc residues in these foods, which can cause various adverse reactions in humans, induce bacterial resistance, and pose a significant threat to public health. Consequently, the detection of Tc antibiotic residues in animal-derived food has become a critical issue. This study aims to establish a novel method for quantifying Tc residues in animal-derived food using quantum dots (QDs) fluorescence immunoassay (FLISA). The developed method was optimized to achieve a detection limit of 0.69 ng/mL and a quantitative detection range of 1.30 ~ 59.22 ng/mL. The applicability of the method was demonstrated by successfully determining Tc residues in pork, chicken, fish, milk, eggs, and honey samples spiked with Tc standard solutions, yielding recoveries ranging from 94.01% to 110.19% and relative standard deviations between 1.10% and 11.39%. The significance of this study lies in its potential to provide a rapid and reliable approach for monitoring Tc residues in animal-derived food products, thereby contributing to the enhancement of food safety monitoring practices.Key points• Screen out tetracycline-specific blocking monoclonal antibodies• The quantitative detection has high specificity and sensitivity• This method can be a useful tool for laboratories or testing facilities