Sensitive, selective screening for allergenic ingredients with internal control is crucial to identify food adulteration and remove allergens from the food chain. Here, loop-mediated isothermal amplification combined with a lateral flow device (LAMP-LFD) was developed for the fast and easy detection of soy DNA. The integrated quality controls included a regular control line to ensure proper implementation (extraction and amplification control) and a second LAMP-LFD assay for the cytochrome oxidase gene, which is a housekeeping gene in plants. The developed LAMP assay showed a limit of detection of only 5 pg DNA input per reaction, for both pure soy and spiked food samples. The test was subsequently implemented for the examination of 32 real food products with different compositions and declared soy contents, and benchmarked against qPCR. Then, this system was combined with a digital cube reader, allowing direct interpretation of the test results, facilitating the point-of-need applicability.

Aflatoxins are highly carcinogenic and mutagenic. Among them, aflatoxin M1 (AFM1) is a hydroxylated metabolite that seriously poses threats to human health and safety, so there is a need to construct an efficient and sensitive detection system for AFM1. In this study, an analytical method was established for ultra-sensitive determination of AFM1 in food based on dendritic hybridization chain reaction (HCR) dual-amplification. The prepared carboxylated silica was modified with AFM1 antibody, dendritic (S) chain and initiator (H0) chain as fluorescent probes, the whole AFM1 antigen was coated on the microplate, and the antibody on the fluorescent probes competed with the AFM1 standard for binding to the whole antigen. Then the fluorescence response value of the supernatant was measured, which displayed a good linear relationship with the standard concentration. The detection range was 10 pg/mL to 10 mu g/mL, and the limit of detection was 5.41 fg/mL, which was in line with the limit value of China's national standard. In addition, the spiked recovery rate was between 84.77 % and 115.70 %. The method developed in this study displays an increase of three orders of magnitude in comparison with indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), in the detection of AFM1, showing ultra-high sensitivity, which satisfies the needs of AFM1 analysis and detection in food. This biosensing method also has reference value for the detection of other toxins in food.

Biodegradable active packaging materials have received extensive attention around the world due to food safety issues and environmental pollution caused by plastic packaging materials. In this study, we present a humidityresponsive multifunctional composite film self-assembled from carboxymethyl cellulose, zein, and cyclodextrin inclusion complexes (PTE@(3-CD ICs). The results show that the addition of PTE@(3-CD ICs can effectively improve the ultraviolet light barrier, elongation at break, surface hydrophobicity, and thermal stability of the films. Adding 10 wt% PTE@(3-CD ICs reduces the water vapor and oxygen transmission rates of the composite films by 22 % and 91 %, respectively. In addition, it confers excellent antimicrobial ability to the films, with the inhibition rate for E. coli and S. aureus being greater than 80 %. The release of pterostilbene from the composite films results in humidity-responsive properties. Fruit preservation experiments further demonstrate that the composite film can delay the transpiration of blueberries and grapes, inhibit microorganism growth, and extend the shelf life of fruits by 50 %-80 %. Moreover, the film completely degrades within 13 days when buried in soil. Such a biodegradable, humidity-responsive, and multifunctional material has broad application prospects in food packaging, and provides a reference for the development of other stimuli-responsive packaging materials.

Given the growing alarms about food safety hazards and the pollution caused by plastic packaging, biodegradable active packaging materials have garnered considerable attention in research circles. In this study, polysaccharide-based metal-organic frameworks were used to produce a composite packaging film as a nonpolluting, biodegradable, and active food packaging material with sustained antimicrobial activity. More specifically, chitosan-proanthocyanidin (CS-PA) affixes were prepared by appending proanthocyanidins onto chitosan via free-radical grafting. ZIF-8 nanoparticles loaded with thymol (denoted as Thy@ZIF-8) were then incorporated into the network architecture of the CS-PA matrix. By utilizing intermolecular hydrogen bonds and Zn2+ ligand interactions, a novel active packaging film was designed. The CS-PA/Thy@ZIF-8 composite film exhibited good microstructural and physicochemical properties. Significantly, the integration of Thy@ZIF-8 within the CS-PA matrix remarkably enhanced the UV-blocking capacity of the composite film and increased its elongation at break. Furthermore, it augmented the water resistance attributes of the film, decreased its water vapor transmission rate, and increased its thermal stability. The slow release of Thy endowed the CS-PA/ Thy@ZIF-8 composite film with an excellent antioxidant activity, along with long-lasting antimicrobial performances against Escherichia coli and Staphylococcus aureus. Moreover, preservation tests showed that the CS-PA/ Thy@ZIF-8 film slowed the spoilage of strawberries by inhibiting bacterial growth, extending the shelf life by 50% at 25 degrees C. A comparable freshness preservation effect was also observed in cherry tomatoes. These results demonstrate that the CS-PA/Thy@ZIF-8 film exhibits good application prospects as a novel biodegradable active packaging material for food preservation.

The ultrasensitive sensor with three optical response mechanisms was proposed for the determination of trace amounts of norovirus using a 3-in-1 GCSNAs (a gap-containing spherical nucleic acid nanoparticles) probe. A simple and highly sensitive three-mode biosensor with Raman, colorimetric, and fluorescence functions was proposed and implemented using the GCSNAs probe and a DNA hydrogel for norovirus detection. When the virus exists, the trans-cleavage activity of CRISPR-Cas12a was activated by double-stranded dsDNA (dsDNA) generated by reverse transcription and recombinase polymerase isothermal amplification (RT-RPA) to degrade the DNA hydrogel/GCSNA composition and release the three-in-one (3-in-1) probe-GCSNA, realising the triple ultrasensitive detection of norovirus. The colorimetric sensing mode allows for semi-quantitative on-site detection, which is visible to the naked eye and the quantitative detection can be achieved by conducting grayscale analysis using the "Colour Grab" function of a smartphone. This new triple sensor achieved the successful quantification of norovirus at concentrations as low as the femtomolar scale with an excellent selectivity and accuracy. Considering the colorimetric properties of rolling circle amplification (RCA)-based DNA hydrogels and GCSNAs, the proposed method has a broad application prospect in virus on-site detection in food. It should be applicable for virus detection in a wide range of fields such, as environmental analysis, medical diagnosis, and food safety. It is anticipated that this mechanism will open new avenues for the development of multimodal analyses and multifunctional sensing platforms for various applications. We anticipate that this sensing mechanism will open up a new way for the development of food safety detection.

Early diagnosis of norovirus (NV) is critical for effective prevention and control of outbreaks. Clustered regularly interspaced short palindromic repeats (CRISPR)-coupled isothermal amplification has been widely employed for the highly sensitive and specific detection of nucleic acids; however, optimizing the compatibility among multi-enzyme reaction systems remains a challenge. In this study, a compartmentalized, self-driven, 3D-printed microfluidic sensor device was developed for cascade isothermal amplification and CRISPR-mediated multistep reactions. This chip integrated the sample pretreatment process with glucose biosensing technology. By leveraging the digital quantification capability of a personal glucose meter (PGM) as an endpoint readout, the system detected NV nucleic acids with high sensitivity and specificity. A series of target RNA concentrations (0.1-10,000 fM) were quantified using the reverse transcription-recombinase polymerase amplification (RT-RPA)-CRISPR sensing method developed in this study. The relationship was linear between the logarithm of the NV target RNA concentration (log C) and the corresponding fluorescence intensity. The RT-RPA-CRISPR assay was further engineered into a microfluidic chip-based point-of-care testing (POCT) system, and the limit of detection of NV was about 60 copies. This integrated approach facilitates field-deployable diagnostics of viral and bacterial pathogens.

Surface-enhanced Raman spectroscopy (SERS) has great potential for the analysis of molecules adsorbed on metals with rough surfaces or substrates with micro-/nanostructures. Plasmonic coupling between metal nanoparticles and the morphology of the rough metal surface can produce "hot spots" that enhance Raman scattering by adsorbed molecules, typically at micro- to nanomolar concentrations, although high enhancement factors can also facilitate single-molecule detection. This phenomenon is widely applicable for chemical analysis and sensing in various fields. In this review, the latest research progress on SERS micro-/nanosensors is evaluated, and the sensors are classified according to their individual functions. Furthermore, the design principles and working mechanisms of reported SERS-active micro-/nanostructured substrates are analyzed, and the design features adopted to overcome the difficulties associated with precision detection are explored. Finally, challenges and directions for future development in this field are discussed. This review serves as a design guide for novel SERS-active substrates.

Two-dimensional transition metal carbides (MXenes) have attracted considerable attention owing to their unique structures and high dielectric losses. To improve the electron transfer ability of electrodes with poor conductivity, highly conductive materials have been incorporated into the surfaces of electrodes modified with metal-organic frameworks (MOFs). Compared to pure metals, MXenes and MOFs exhibit similarly high conductivities while offering enhanced dispersion in multipolar solvents and broader tunability. Titanium carbide (Ti3C2Tx) is a representative MXene with numerous exposed functional groups on its surface, including hydroxyl, O, and fluorine groups. These functional groups attach to semiconductor materials via electrostatic interactions or H bonds, endowing the supramolecular assembly of MOFs and Ti3C2Tx with high conductivity at the macro level. The resistance variations in MOF/Ti3C2Tx are reflected in the formation of Schottky junctions, which provide a host platform for MOFs. This review provides an evaluation of the latest research frontiers in the MOF/MXene direction by categorizing the sensors based on their target detection. Moreover, the design principles and working mechanisms of previously reported MOF/MXene detection sensors are summarized and the design features adopted to address the difficulties in synthesis are described. Finally, the challenges and future development prospects in this field are discussed.

Ochratoxin A (OTA) is a potent carcinogen, and is among the most dangerous mycotoxins in agricultural products. In this study, an ultrasensitive dual-mode immunosensor was developed for naked-eye and fluorescence detection of OTA based on Ag-doped core-shell nanohybrids (Ag@CSNH). Complete antigen-labeled Ag@CSNH (CA-Ag@CSNH) were used as a competitive bind and dual-mode probe. The diffused doping structure of CA-Ag@CSNH provided improved stability, color and fluorescence quencher performance. Antibodies modified magnetic beads were used as a capture probe. The competitive binding between OTA and CAAg@CSNH produced both color change and fluorescence quenching. Ultraviolet and fluorescence intensitie correlated linearly with OTA concentration ranges of 0.03-3 ng/mL and 10-10000 pg/mL, and limits of detection of 0.0235 ng/mL and 0.9921 pg/mL, respectively. The practical applicability of proposed strategy was demonstrated by analysis of OTA in spiked corn, soybean and flour samples. This study offers a new insight on multi-mode platforms for various applications.

Wearable electronic devices find increasing applications in mobile medical sensing and monitoring, human–computer interaction, and portable energy collection and storage, owing to their flexibility and stretchability. In recent years, transition metal nitrides and carbides, known as MXenes, have become cornerstones for the preparation of novel flexible electronic devices because of their excellent electrical conductivities, abundant surface functional groups, and large specific surface areas. This review presents the latest developments in MXene-based wearable electronic products, including hydrogels, paper, composite materials, and self-powered devices. These products can be integrated with artificial intelligence to show unique applications in healthcare, inspection, and control of human-like machines. The application prospects of MXenes in the new generation of wearable electronic devices are forecast, the challenges and difficulties in designing MXene-based wearable electronic devices are discussed, and corresponding solutions are suggested. This review also provides future research directions for the development of MXenes for pliable and wearable applications.

Mycotoxins are secondary products produced primarily by fungi and are pathogens of animals and cereals, not only affecting agriculture and the food industry but also causing great economic losses. The development of rapid and sensitive methods for the detection of mycotoxins in food is of great significance for livelihood issues. This study employed an amino-functionalized zirconium luminescent metal–organic framework (LOF) (i.e., UiO-66-NH2). Click chemistry was utilized to assemble UiO-66-NH2 in a controlled manner, generating LOF assemblies to serve as probes for fluorescence-linked immunoassays. The proposed fluoroimmunoassay method for Zearalenone (ZEN) and Fumonisin B1 (FB1) detection based on the UiO-66-NH2 assembled probe (CLICK-FLISA) afforded a linear response range of 1–20 μmol/L for ZEN, 20 μmol/L for FB1, and a very low detection limit (0.048–0.065 μmol/L for ZEN; 0.048–0.065 μmol/L for FB1). These satisfying results demonstrate promising applications for on-site quick testing in practical sample analysis. Moreover, the amino functionalization may also serve as a modification strategy to design luminescent sensors for other food contaminants.

As global environmental pollution increases, climate change worsens, and population growth continues, the challenges of securing a safe, nutritious, and sustainable food supply have become enormous. This has led to new requirements for future food supply methods and functions. The use of synthetic biology technology to create cell factories suitable for food industry production and renewable raw material conversion into: important food components, functional food additives, and nutritional chemicals, represents an important method of solving the problems faced by the food industry. Here, we review the recent progress and applications of synthetic biology in the food industry, including alternatives to: traditional (artificial pigments, meat, starch, and milk), functional (sweeteners, sugar substitutes, nutrients, flavoring agents), and green (green fiber, degradable packing materials, green packaging materials and food traceability) foods. Furthermore, we discuss the future prospects of synthetic biology-based applications in the food industry. Thus, this review may serve as a reference for research on synthetic biology in the: food safety, food nutrition, public health, and health-related fields. [GRAPHICS]

By inhibiting acetylcholinesterase (AChE) activity, organophosphate compounds (OPs) can quickly cause severe injury to the nervous system and death, making it extremely difficult to rescue victims after OP exposure. However, it is quite challenging to construct scavengers that neutralize and eliminate these harmful chemical agents promptly in the blood circulation system. Herein, we report an enzyme-armed biomimetic nanoparticle that enables a ‘targeted binding and catalytic degradation’ action mechanism designed for highly efficient in vivo detoxification (denoted as ‘Nanocleaner’). Specifically, the resulting Nanocleaner is fabricated with polymeric cores camouflaged with a modified red blood cell membrane (RBC membrane) that is inserted with the organophosphorus hydrolase (OPH) enzyme. In such a subtle construct, Nanocleaner inherits abundant acetylcholinesterase (AChE) on the surface of the RBC membrane, which can specifically lure and neutralize OPs through biological binding. The OPH enzyme on the membrane surface breaks down toxicants catalytically. The in vitro protective effects of Nanocleaner against methyl paraoxon (MPO)-induced inhibition of AChE activity were validated using both preincubation and competitive regimens. Furthermore, we selected the PC12 neuroendocrine cell line as an experimental model and confirmed the cytoprotective effects of Nanocleaner against MPO. In mice challenged with a lethal dose of MPO, Nanocleaner significantly reduces clinical signs of intoxication, rescues AChE activity and promotes the survival rate of mice challenged with lethal MPO. Overall, these results suggest considerable promise of enzyme-armed Nanocleaner for the highly efficient removal of OPs for clinical treatment.

Two-dimensional transition metal carbides (MXenes) have attracted considerable attention owing to their unique structures and high dielectric losses. To improve the electron transfer ability of electrodes with poor conductivity, highly conductive materials have been incorporated into the surfaces of electrodes modified with metal–organic frameworks (MOFs). Compared to pure metals, MXenes and MOFs exhibit similarly high conductivities while offering enhanced dispersion in multipolar solvents and broader tunability. Titanium carbide (Ti3C2Tx) is a representative MXene with numerous exposed functional groups on its surface, including hydroxyl, O, and fluorine groups. These functional groups attach to semiconductor materials via electrostatic interactions or H bonds, endowing the supramolecular assembly of MOFs and Ti3C2Tx with high conductivity at the macro level. The resistance variations in MOF/Ti3C2Tx are reflected in the formation of Schottky junctions, which provide a host platform for MOFs. This review provides an evaluation of the latest research frontiers in the MOF/MXene direction by categorizing the sensors based on their target detection. Moreover, the design principles and working mechanisms of previously reported MOF/MXene detection sensors are summarized and the design features adopted to address the difficulties in synthesis are described. Finally, the challenges and future development prospects in this field are discussed.

To reduce the crop losses associated with biotic and abiotic stresses, novel sensor technologies that can monitor plant health and predict and track plant diseases in real time are required. Plant sensors based on wearable technologies are placed directly on the plant leaf or stem. The health status of the plant is reflected by various biomarkers and microenvironmental parameters, which are converted into electric readouts by the sensors for convenient analysis. Herein, the latest research progress in the field of wearable plant sensors is evaluated, and the sensors are classified according to their individual functions. Moreover, the design principles and working mechanisms of previously reported wearable sensors are analyzed, and the design features adopted to overcome the difficulties associated with precision agriculture are explored. Finally, the challenges and future development prospects in this field are outlined. This review contributes to the growing body of literature on wearable plant sensors, underscoring their critical role in mitigating crop losses through real-time plant health monitoring and disease prediction. Advancements in wearable plant sensors could ultimately revolutionize crop production and sustainability by enabling more precise, efficient, and proactive farming practices.

Bacteria-infected skin wounds caused by external injuries remain a serious challenge to the whole society. Wound healing dressings, with excellent antibacterial activities and potent regeneration capability, are increasingly needed clinically. Here, we reported a novel functional microneedle (MN) array comprising methacrylated hyaluronic acid (MeHA) embedded with pH-responsive functionalized zeolitic imidazolate framework-8 (ZIF-8) nanoparticles to treat bacteria-infected cutaneous wounds. Antibacterial activity was introduced into Zn-ZIF-8 to achieve sterilization through releasing Zn ions, as well as increased angiogenesis by dimethyloxalylglycine (DMOG) molecules that were distributed within its framework. Furthermore, biodegradable MeHA was chosen as a substrate material carrier to fabricate DMOG@ZIF-8 MN arrays. By such design, DMOG@ZIF-8 MN arrays would not only exhibit excellent antibacterial activity against pathogenic bacteria but also enhance angiogenesis within wound bed by upregulating the expression of HIF-1α, leading to a significant therapeutic efficiency on bacteria-infected cutaneous wound healing. Based on these results, we conclude that this new treatment strategy can provide a promising alternative for accelerating infected wound healing via effective antibacterial activity and ameliorative angiogenesis.

Effective and real-time detection of lactate (LA) content in human sweat has attracted considerable attention from researchers. In this work, a novel electrochemical paper-based analysis device (ePAD) was developed for the non-invasive detection of LA in sweat. The electrocatalytic properties of AuNP/Cu-TCPP(Fe) hybrid nanosheets, which were prepared by an optimised synthetic method, were studied by CV and EIS electrochemical methods for the first time and the working electrode can be fabricated using a drip coating method. The lactate sensor was optimised and validated for usability, adoptability and interpretability. To the best of our knowledge, this was the fastest, lowest detection line and widest linear range method reported to date for the detection of lactate. It achieved the detection limit of 0.91 pM and a linear range from 0.013 nM to 100 mM. The dual catalytic effects of the hybrid NSs shortened the detection time by nearly two times and enhanced the sensitivity approximately two times, an accuracy unmatched until now. Furthermore, this sensor was employed for LA analysis and validated by high performance liquid chromatography (HPLC). The ePAD shows superior biocompatibility, accuracy, and high sensitivity and can be easily manufactured. Hence, it is applicable for the long-term monitoring of sweat LA concentrations in point-of-care testing, athletic testing of athletes and military personnel and other subjects in different extreme environments.

Mycotoxin pollutants removal using adsorbents has been studied extensively in recent years, although the development of low-cost, recyclable, and highly efficient adsorbents remains a challenge to date. Covalent Organic Frameworks (COFs) represent a novel kind of porous crystalline material, which have been applied widely. In this work, a flower-like COF fiber membrane (PAN@COF FM) for adsorbing Aflatoxin B1 was fabricated using a simple approach. The COF was grown on the surface of polyacrylonitrile (PAN) skeleton using the in situ growth method. Then, the AFB1 adsorption performance of the prepared membrane and the underlying adsorption mechanism were studied. The results revealed that the activated PAN@COF FM reached adsorption equilibrium within 30 min. The used membranes were regenerated by washing with an alkaline solution and then tested for adsorption efficiency again. The PAN@COF FM could adsorb above 98% Aflatoxin B1 after 10 cycles, indicating its good reusability. The well adsorption performance of the membrane was attributed to the rr-rr stacking, hydrogen bonding, and hydrophobic interactions between PAN@COF FM and Aflatoxin B1. In summary, the as-prepared PAN@COF FM possesses the advantage of high reusability and good adsorption performance, and has the promising application in pollutant removal.

Nucleic acid markers have been widely used in the detection of various virus-related diseases, including hepatitis B virus (HBV), which is spreading worldwide. The trans-activated CRISPR-Cas system has shown excellent sensitivity and specificity in nucleic acid detection. However, nucleic acid testing usually requires amplification of the target nucleic acid for more accurate and specific detection; furthermore, current nucleic acid assays are time-consuming, costly, and are limited by non-specific cross-reactivity. We developed an amplification-free viral DNA biosensor-based diagnostic method that uses a clustered regularly interspaced short palindromic repeats-associated system (CRISPR/Cas)-based approach with surface enhanced Raman spectroscopy. This method can specifically identify the target site by changing the crRNA sequence. In addition, the incubation period and development of the disease can be determined by quantitative detection of viral DNA. This system could achieve rapid and highly sensitive detection of HBV DNA within 50 min and vast detection range from 0.1 pM to 1 nM. Therefore, a combined CRISPR/Cas12a-SERS-based assay would improve the sensitivity of detection in assays using multiple biomarkers. In conclusion, our CRISPR/Cas12a-based biosensor would enable rapid, simple, and sensitive detection of HBV nucleic acids.

In this study, we introduced a Raman detection technique based on a combination of functionalized magnetic beads and surface-enhanced Raman scattering (SERS) tags to develop a rapid and sensitive strategy for the detection of Staphylococcus aureus (S. aureus), a typical foodborne pathogen. Polyethylene glycol (PEG) and bovine serum albumin (BSA) dual-mediated teicoplanin functionalized magnetic beads (TEI-BPBs) were prepared for separation of target bacteria. SERS tags were used to immobilize antibodies on gold surfaces with bifunctional linker proteins to ensure specific recognition of S. aureus. Under optimal conditions, the combination of TEI-BPBs and SERS tags showed reliable performance, exhibiting good capture efficiency even in the presence of 106 CFU mL-1 of non-target bacteria. The SERS tag provided an effective hot spot for subsequent Raman detection, presenting good linearity in the range of 102-107 CFU mL-1. Good performance has also been shown in detecting target bacteria in milk samples, where it has a recovery of 95.5-101.3%. Thus, the highly sensitive Raman detection technique combined with TEI-BPBs capture probes and SERS tags is a promising method for the detection of foodborne pathogens in food or clinical samples.