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AbstractInnovating food additives stands as a cornerstone for the sustainable evolution of future food systems. Peptides derived from food proteins exhibit a rich array of physicochemical and biological attributes crucial for preserving the appearance, flavor, texture, and nutritional integrity of foods. Leveraging these peptides as raw materials holds great promise for the development of novel food additives. While numerous studies underscore the potential of peptides as food additives, existing reviews predominantly focus on their biotic applications, leaving a notable gap in the discourse around their abiotic functionalities, such as their physicochemical properties. Addressing this gap, this review offers a comprehensive survey of peptide-derived food additives in food systems, accentuating the application of peptides’ abiotic properties. It furnishes a thorough exploration of the underlying mechanisms and diverse applications of peptide-derived food additives, while also delineating the challenges encountered and prospects for future applications. This well-time review will set the stage for a deeper understanding of peptide-derived food additives. [ABSTRACT FROM AUTHOR]

Microbiological safety of food is closely related to the activities of foodborne microorganisms, which is among the critical issues in the food industry that require careful screening. A series of analytical techniques have been employed for microbiological food safety detection but renders either analytical defects or practical limitations. With the sensitive and fingerprint sensing ability of surface-enhanced Raman scattering (SERS) technique and the easy operations of magnetic entities (MEs), SERS-based magnetic platforms (MagSERS) emerge as a potent candidate for the analysis of microbiological foodborne hazards. The current review focuses on the fundamentals and recent applications of MagSERS in microbiological safety of food. In this review, the design and fabrication of MagSERS are introduced, which comprises the functionalized MEs plus noble-metal SERS substrates, magnetic nanocomposites plus noble-metal SERS substrates, and magnetic SERS substrates, and the detection principles of MagSERS are illustrated in detail, including the combination of magnetic capture, separation, and enrichment of targets (via recognition elements functionalized MEs) with SERS substrates, as well as the magnetism-mediated hotspot engineering of SERS substrates. In addition, the current advances in MagSERS methods for detecting foodborne bacteria, biological toxins, and viruses are summarized and future perspectives for the food industry are also given. Key findings and conclusions : As demonstrated by the publications in the field, MagSERS that merges magnetic properties and SERS spectra can facilitate the detection of foodborne biohazards for their excellent target separation and enrichment (sampling), simplified assay procedures (assaying), optimized SERS effect and signal or signalling. As such, MagSERS platforms show a promising prospect in the construction of more simple, rapid, and sensitive biosensors for food safety. • Design, fabrication, and principles of diverse types of MagSERS are presented. • Current advances and future trends of MagSERS for food bioanalysis are proposed. • MagSERS is featured with simple sampling, rapid assaying, and sensitive signalling. • MagSERS can be used for assaying foodborne bacteria, biotoxins, and viruses. [ABSTRACT FROM AUTHOR]

Along with the intensification of global food supply, food security has become a fateful barrier throughout the global food trade and delivery. Reliable analytic techniques are in strong need to keep up with the continuous demand for food quality and safety monitoring. In this review, the current strategies for different fluorescence mechanisms of MOF-based sensors for food detection are classified and we highlight the construction strategy of MOFs to obtain high performance and multiple photonic function. In addition, recent applications of LMOFs in food safety analyzing as well as the typical sensing mechanisms are reviewed. Finally, we also outline the challenges in these fields and put forward the prospects for future development of LMOFs in food analysis. Fluorescent MOFs have been utilized as sensors to alleviate the food safety problems. The vast combination possibilities, synergistic effects, as well as controllable and ordered arrangements of multiple fluorescent units have distinguished MOFs from other analysis techniques and enabled them to be a promising platform for food quality and safety control. Reasonable crystal engineering principles offers MOFs with the structure–property correlations and varied fluorometric sensing properties, resulting in a rapidly increasing application in food safety. [Display omitted] • Novel analytic techniques facilitate better food safety control. • Luminescent MOFs have been well developed as sensors. • The flexible design enables MOFs capable of complicated food system. • The fluorescence mechanisms of LMOFs for food detection are classified. • The recent food applications and future trends of LMOFs are summarized. [ABSTRACT FROM AUTHOR]

For survival and quality of life, human society has sought more productive, precise, and sustainable agriculture. Agrochemistry, which solves farming issues in a chemical manner, is the core engine that drives the evolution of modern agriculture. To date, agrochemistry has utilized chemical technologies in the form of pesticides, fertilizers, veterinary drugs and various functional materials to meet fundamental demands from human society, while increasing the socio-ecological consequences due to inefficient use. Thus, more useful, precise, and designable scaffolding materials are required to support sustainable agrochemistry. Reticular chemistry, which weaves molecular units into frameworks, has been applied in many fields based on two cutting-edge porous framework materials, namely metal–organic frameworks (MOFs) and covalent-organic frameworks (COFs). With flexibility in composition, structure, and pore chemistry, MOFs and COFs have shown increasing functionalities associated with agrochemistry in the last decade, potentially introducing reticular chemistry as a highly accessible chemical toolbox into agrochemical technologies. In this critical review, we will demonstrate how reticular chemistry shapes the future of agrochemistry in the fields of farm sensing, agro-ecological preservation and reutilization, agrochemical formulations, smart indoor farming, agrobiotechnology, and beyond. [ABSTRACT FROM AUTHOR]

An isoreticular principle guides the directed evolution of domino reactions in MOF nanozymes against antibacterial resistance. The Ce-UiO-66 nanozymes, with linker-dependency on dual hydrolytic and redox mimicry, couple ATP depletion and ROS generation into a unique biofilm microenvironment-responsive prodrug-mimicking domino reaction, enabling the kinetically favourable Ce-UiO-66-NO 2 to effectively target and inhibit MRSA biofilm at the initial bacterial adhesion stage. [Display omitted] • Isoreticular chemistry accelerates the directed nanozyme discovery of Ce-MOFs. • Linker dependence Ce-UiO-66-X modulates dual apyrase and oxidase biomimicry; • Domino effect of the hydrolytic and redox activities in Ce-UiO-66-X is revealed; • Domino reaction in Ce-UiO-66-X couples ATP hydrolysis and ROS generation; • Ce-UiO-66-X enables microenvironment-responsive disinfection of MRSA biofilm. Nanozyme therapy holds promise for overcoming daunting antimicrobial resistance, but skills to target the microbial microenvironment are lacking. Herein, an isoreticular principle was introduced in nanozyme discovery to directedly evolve a domino biomimetic reaction specific to drug-resistant bacterial biofilm. The isoreticular Ce-UiO-66-X (X = BDC, BDC-CH 3 , BDC-OH, BDC-NH 2 , BDC-NO 2 , ADC, Fum) MOFs exhibited linker-dependent mimicry of hydrolytic apyrase and redox oxidase, and the phosphorous reactants (ATP/ADP/AMP/Pi) produced by the ATP hydrolysis could spontaneously activate redox reaction in Ce-UiO-66-X. Evidenced by the representative Ce-BDC-X (X = –NO 2 , -H, and –NH 2) nanozymes, the unique domino reaction of Ce-UiO-66-X could simultaneously deplete ATP molecules and trigger enhanced generation of superoxide radicals at the specific time window in the initial bacterial adhesion stage of methicillin-resistant Staphylococcus aureus (MRSA) biofilm formation. Due to the synergistic nanocatalytic mechanism, possible nanoscale penetration effect, and good biocompatibility, Ce-UiO-66-NO 2 could effectively target and destroy the metabolic microenvironment of MRSA biofilm in vitro and in vivo, reducing the MRSA biofilm viability to as low as 3.64%. This work demonstrates a new prodrug-like enzymodynamic antibacterial therapeutics based on cooperative multienzyme reactivity. [ABSTRACT FROM AUTHOR]

• Discovery of oxidase-like activity and degradable property of γ-MnOOH nanowires. • Understanding of the degradation-activity correlation of γ-MnOOH nanozymes. • Designing a colorimetric platform for POC detection of OPs and AChE activity. • Low LODs, high selectivity, anti-interfere capacity, and workable in real samples. • This portable detection platform possessing great ecological sustainability. Despite the tremendous achievements of existing sensing techniques, sensitive and portable sensing of organophosphorus pesticides (OPs) in a non-polluting manner remains a challenging issue. This work proposed a facile colorimetric paper sensor using γ-MnOOH nanowires (NWs) as a degradable nanozyme and 3,3′,5,5′-tetramethylbenzidine (TMB) as a chromogenic indicator for rapid and sensitive screening of OPs and acetylcholinesterase (AChE) activity. The sensing mechanism was based on the easy disintegration of the oxidase-like γ-MnOOH NWs into invalid Mn2+ ions by the selective reaction with thiocholine (TCh) produced by AChE and acetylthiocholine iodide (ATCh), triggering a remarkable activity loss of MnOOH nanozymes towards TMB oxidation. The concentration of OPs, as an AChE inhibitor, was measured by the changes in absorbance at 652 nm or blue color of oxTMB products. Such detection platform in solution state achieved relatively low limits of detection (LODs) for AChE activity (0.007 mU mL−1), and for two typical OPs, i.e., omethoate (0.35 ng mL−1) and dichlorvos (0.14 ng mL−1), respectively. Further, the portable assembly of such AChE-nanozyme tandem reaction on test paper performed well, reaching LODs of 0.1 mU mL−1 for AChE, 10 ng mL−1 for omethoate, and 3 ng mL−1 for dichlorvos, respectively. Meanwhile, this sensing system showed great selectivity and anti-interfering capacity in both solution and solid states, and worked well in real serum and vegetable samples. The abovementioned results, along with evidence of its good ecological sustainability, demonstrated the superiority of this well-performing platform for application in the food, environmental, and medical fields. [ABSTRACT FROM AUTHOR]

Nanozyme technique with efficient modulating strategies is a promising tool for biocatalytic and biosensing applications, yet insights into target-responsive controllability of oxidase nanozymes remain largely unknown. In this contribution, we report a state-of-art oxidase-like and ssDNA-tunable nanozyme for biomolecular recognition. In detail, the spinel-type manganese cation substituted cobalt oxide (MnCo 2 O 4 ) submicrospheres can imitate oxidase for efficiently catalytic oxidation of colorimetric substrate, superior to current metal oxide-based oxidase nanozymes. More importantly, the nanozyme activity of spinel MnCo 2 O 4 can be reversibly inhibited by the attachment/detachment of aptamer strands on MnCo 2 O 4 surface via the aptamer-target binding event, enabling a new colorimetric access for detecting biomolecules. Taking highly toxic ochratoxin A (OTA) as model molecule, we can selectively determine OTA in maize samples with a limit of detection (3δ/ S ) of 0.08 ng/mL. The unique nanozyme property of spinel MnCo 2 O 4 , together with the principle of our approach, reveals the potential of ssDNA-tailorable oxidase nanozymes in biocatalytic and biosensing fields. [ABSTRACT FROM AUTHOR]

Nanozymes, as a robust alternative to natural enzyme, usually suffer from unsatisfactory catalytic efficiency and limited modulating flexibility. Herein, we proposed a novel strategy to conquer these disadvantages relying on the facet-selective response of external trigger molecule which boosts the oxidase-like catalysis of nanoceria. Results indicate that the trigger molecule (i.e., sulfate ion) prefers to bind to the rod-like nanoceria (on its unique {1 1 0} facets) rather than nanopolyhedra or nanocubes. Sulfate ion-treated CeO 2 nanorods (SO 4 2− /CeO 2 NRs) became modulatable oxidase mimetics of high efficiency, and the catalytic efficiency ( k cat / K m ) of SO 4 2− /CeO 2 NRs improved by nearly 20-fold (versus that of the naked CeO 2 NRs) for 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation. This modulating strategy, together with the mechanism behind, is finally applied to develop colorimetric biosensors, which paves the way for embedding the system in biological and environmental networks. [ABSTRACT FROM AUTHOR]

The growing concerns about microbial food safety and environmental contamination call for sustainable food active packaging materials and practices with high performance. This contribution proposed a biocatalytic spraying coating for fruit preservation using carboxymethyl cellulose nanofibers grafting enzyme-like metal-organic frameworks (CNF@Ce-MOF) with banana and mango as model fruits. The well-characterized biohybrid nanofibers were verified to simultaneously mimic good oxidase-like and apyrase-like activities, enabling effective enzyme-like sterilization against three typical foodborne pathogens, i.e. Escherichia coli O157: H7, Staphylococcus aureus , and methicillin-resistant Staphylococcus aureus , reaching killing rates as high as 90.46%. The biocidal •O 2 − generation and adenosine triphosphate depletion were the possible mechanisms causing the nonspecific bacteria death. Such antibacterial performance, as well as additional protective properties of CNF@Ce-MOF, facilitated the quality preservation during the 12-day storage of bananas and mangos by spray coating with the biomimetic CNF@Ce-MOF. It is expected that this work walks out the first step of nanozyme toward active packaging engineering for the fields of food, agriculture, and biomedicine. [Display omitted] • Biopolymeric nanozyme was created by biomineralizing in situ MOF on nanocellulose. • Dual enzyme biomimicry by CNF@MOF produced.•O 2 − species and depleted ATP • CNF@MOF possessed bacteriostatic activities, UV resistance and biocompatibility. • Pioneering research was conducted by introducing nanozyme into active packaging. • CNF@MOF coating improved quality and extended shelf life of banana and mango. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lysozyme is immobilized on Ti 3 C 2 T X MXene nanosheets modified with polydopamine. • The light-switchable enzymatic antibacterial platform is constructed. • The antibacterial activity against MRSA improves after NIR light irradiation. Being a unique biocatalyst to hydrolyse structural polysaccharides on the cell wall of bacteria, lysozyme can slow down bacterial resistance caused by antibiotic overdose treatments, however, efficient activation of lysozyme activities under pathogenic microenvironments remains challenging. Herein, a bio-interface engineering strategy was proposed for the remote modulation of thermoresistant lysozyme upon rationally designed photothermal nanoplatforms. For this, Ti 3 C 2 T X MXene nanosheets were functionalized by polydopamine (PDA) surface chemistry to enhance photothermal effects and performance durability, during which lysozyme biomacromolecules were immobilized at such a two-dimensional hybrid interface via intermolecular electrostatic affinity. The integrated nanoplatform (denoted as M@P@Lyso), with an optimal high light-to-heat conversion efficiency of 46.88%, realized not only precision control of local heat but also photo-responsive up-regulation for bio-catalysis of laden lysozyme. As a result, in vitro and in vivo antibacterial experiments revealed that M@P@Lyso could effectively inhibit the proliferation of methicillin-resistant Staphylococcus aureus and accelerated wound disinfection of mice with negligible biological toxicities. The outstanding antibacterial activities of M@P@Lyso were attributed to the photo-enhanced lysozyme activity, assisted by bacterial death caused by the mild local hyperthermia and the physical destruction derived from the M@PDA. This work exemplified a solution to the bacterial resistance threats via stimuli-responsive enzymatic nanoplatforms. [ABSTRACT FROM AUTHOR]

Gold nanorods (GNRs) outstand in photothermal disinfection but are faced with severe surface chemistry and dose relevant biotoxicity. Herein, a naturally green building block, metal-phenolic networks (MPNs), was employed to functionalize GNRs via coordination reaction, yielding a tunable and biocompatible core-shell photothermal nano-bactericide (GNRs@MPNs). The bioactive GNRs@MPNs built with iron and polyphenols (tannic acid, epigallocatechin gallate, and procyanidins) exhibited superior light-to-heat conversion efficiencies with η = 29.29–44.00%, remarkably preceding that of GNRs (η = 12.24%), which could rapidly ablate 99.8% of Escherichia coli O157: H7 and 98.6% of Staphylococcus aureus bacteria in relatively low efficacy doses (10 ppm of Au). Moreover, local heat triggered by GNRs@MPNs accelerated the healing of the cutaneous wound of a mice model infected by methicillin-resistant S. aureus. The facile synthesis, photothermal synergy, polyphenolic bioactivity, and significantly low efficacy dose of GNRs@MPNs empower them satisfactory efficiency and biosafety in the future broad-spectrum photothermal sterilization applications. [ABSTRACT FROM AUTHOR]

Efficient identification of pathogenic bacteria is greatly concerned with microbial food safety and foodborne diseases diagnosis. Surface-enhanced Raman scattering (SERS) tags are among the cutting-edge tools for bioanalysis, but facing troubles in either SERS sensitivity, durability, interfering signals, or universal recognition agents for target bacteria. This work proposed a multivariate scheme enabled by polyphenolic chemistry for the green synthesis, facile stabilization (functionalization), protective encapsulation, and bio-affinitive design of metal-phenolic networks (MPNs)-encapsulated silver SERS nanotags (AgNPs@4-mercaptobenzonitrile@MPNs). With remarkable SERS properties, shelf stability, and bacterial affinity, AgNPs@4-mercaptobenzonitrile@MPNs tags enabled rapid, reproducible, and interference-free SERS detection of two representative foodborne pathogens (i.e., E. coli O157: H7 and S. aureus) in the assistance of an aptamer-labelled magnetic probe, reaching good sensitivity and selectivity. Moreover, this SERS biosensor worked well in real food samples, manifesting the potential of polyphenolic chemistry in the customization of bio-affinitive SERS nanotags for food safety detection. [Display omitted] • Polyphenolic chemistry enabled from-synthesis-to-bioaffinity scheme of SERS tags. • Metal-phenolic networks acted as bioaffinity elements for bacterial recognition. • Polyphenolic SERS tags could be reliable detection probe for bacteria quantitation. • Polyphenolic SERS biosensor could detect foodborne bacteria down to 102 CFU/mL. • The SERS biosensor could work in milk and beef samples. [ABSTRACT FROM AUTHOR]

With the globalization of food supplies and worldwide concerns about foodborne illness, the food industry is confronting unprecedented safety challenges. Dyestuff chemistry, nanotechnology, and immunochromatography assay (ICA) have all been hot topics in recent decades, particularly in the respective professions. Regardless, the respective superiorities and weaknesses are difficult to integrate and overcome, hindering the widespread deployment in the food safety sector. In this review, the historical development and current mechanism design for various analysis patterns of dyestuff chemistry-encode signal tracers-based ICAs (dyestuff-based ICAs) for food safety monitoring are classified. And we highlight the construction strategy of dyestuff-encode signal tracers to obtain simpler steps, enhanced utilization efficiency, and brand-new function. Furthermore, the unique superiority and recent applications of dyestuff-based ICAs for food safety monitoring, as well as future-oriented innovation are reviewed. Finally, the challenges in this field were also spotlighted along with the outlook of profound developments for dyestuff-based ICAs in point-of-care (POC) settings. Dyestuff-based ICAs that combine multiple technologies emerge as POC tools for performing global food safety control owing to the rapidness, user-friendliness, and attraction on future-oriented innovation. Particularly with the maturation of traditional dyeing methods and the commercialization of related dyestuffs, dyestuff-based ICAs possess several merits, including cost-effectiveness, ease-of-labeling, and high performance while significantly shortening the distance from raw materials to ICA-based products. Following the advances in interdisciplinary innovations, dyestuff-based ICAs will undoubtedly reduce (or even eliminate) the inefficient back-and-forth between laboratories and tables, and spark a revolution in this field. Dyestuff chemistry-encoded signal tracers based immunochromatographic assays facilitates the POC deployment for food safety monitoring. [Display omitted] • Novel analytic techniques shortening the distance from raw materials to products. • Dyestuff-based ICAs offers excellent platform for food safety detection. • Simplified steps, enhanced efficiency, and brand-new sandwich pattern are created. • The mechanisms design of dyestuff-based ICAs for food detection are classified. • Strengths, barriers, recent food applications and future trends are summarized. [ABSTRACT FROM AUTHOR]

Controlled release (CR) systems have become a powerful platform for accurate and effective delivery of bioactive compounds (BCs). Metal-organic frameworks (MOFs) are one of the best BCs-loaded carriers for CR systems. In the review, the principles and methods of the design and synthesis of MOFs-CR systems are summarized in detail, the encapsulation of BCs by MOFs and CR mechanisms are explored, and their biological toxicity and biocompatibility are highlighted and applications in the food industry are discussed. In addition, current challenges in this field and possible future development directions are also presented. MOFs have been proven to encapsulate BCs effectively, including gaseous and solid molecules, and control the release of BCs through spontaneous diffusion or stimulus-response. The solubility, stability and biocompatibility of BCs encapsulated by MOFs are greatly improved, which expands their applications in foods. The effective CR of BCs by MOFs-CR systems is beneficial to assist in maintaining or even improving the quality and safety of food, reduce the BCs usage while increasing the bioavailability. Low- or non-biotoxic MOFs, especially bio-MOFs, show greater application prospects in the food industry. [ABSTRACT FROM AUTHOR]

• MoS 2 /g-C 3 N 4 HNs as 2D/2D heterojuncted nanozyme were prepared via a one-pot bottom-up process. • MoS 2 /g-C 3 N 4 HNs show enhanced peroxidse-like activty than the individual compoments. • A sensor for S2− detection based on MoS 2 /g-C 3 N 4 HNs as nanozyme has been constructed. • This S2− sensor exhibits high performance with detection limit as low as 37 nM. The cutting-edge nanozyme-based strategy for rapid detection remains significantly limited by the lack of simple synthetic method with ideal catalytic activity. In this regard, 2D nanozymes has recently emerged as a group of promising nanozymes because of their unique enzyme mimicking properties. Herein, via one-pot bottom-up co-calcination, we report a robust strategy to promote the peroxidase-like activity of 2D nanozyme by rational fabricating a 2D/2D heterojuncted nanozyme: MoS 2 /g-C 3 N 4 heterojuncted nanosheets (MoS 2 /g-C 3 N 4 HNs). With merits of the acceleration of electron transfer and the synergistic effect of MoS 2 and g-C 3 N 4 as well as high affinity to the catalytic substrates, the 2D/2D MoS 2 /g-C 3 N 4 heterojuncted nanozyme shows enhanced peroxidase-like activity over the pure g-C 3 N 4 nanosheets and MoS 2 nanosheets. As a proof-of-concept application, a colorimetric sensor based on this 2D/2D heterojuncted nanozyme was developed to detect sulfide ions (S2−), and the detection limit was found to be as low as 37 nM. Therefore, the current work not only demonstrates a powerful strategy to improve the activity of 2D nanozymes but also establish a facile approach for water-safety monitoring. [ABSTRACT FROM AUTHOR]

Food safety has attracted considerable attention in recent years. As a rapid, fingerprint-type recognition and nondestructive detection technique, surface-enhanced Raman scattering (SERS) has been among the promising techniques to meet the increasing needs for food safety analysis. Currently, emerging flexible SERS substrates as an alternative for colloidal and rigid SERS substrates have received great interest. Flexible SERS substrates possess the advantages of easy sampling by wrapping or swabbing on nonplanar surfaces, which facilitate the detection of contaminants from food surfaces and shed new lights on the nondestructive and sensitive detection of food analytes. In this review, the characteristics of different flexible materials such as cellulose, polymer film, cotton fabric, adhesive tape and bio-materials for constructing flexible SERS substrates are introduced, detection strategies including infiltration scheme, swab-sampling and in-situ detection are discussed, and recent applications of flexible SERS substrates in detecting trace pesticides in fruits and vegetables, chemical residues in animal farming including fungicides and antibiotics, illegal food additives and food-borne pathogens are highlighted. Flexible SERS substrates have been increasingly studied for detecting food contaminants. In preparing SERS substrates, different properties of the materials should be considered. For the detection strategies, compared with conventional infiltration scheme, swab-sampling is unique for flexible substrates and can collect target molecules directly from the surface, while in-situ detection is the most convenient, facile and nondestructive. Encouraging application results available show that flexible SERS substrates possess enormous potentials for food safety analysis and surveillance. • Flexible SERS substrates can provide rapid and nondestructive detection for foods. • Materials for constructing flexible SERS substrates are highlighted. • Different detection strategies using flexible SERS substrates are compared. • Recent applications of flexible SERS substrates in food safety are summarized. • Challenges and development of flexible SERS substrates are discussed. [ABSTRACT FROM AUTHOR]

• SERS-based innovative nanohybrid platforms are promising tools in safety control of food supply chain. • Summarizing the significance of function-oriented design and applications of versatile hybrid SERS substrates in addressing concerns in food supply chain safety and beyond. • Systematic review of nanohybrid SERS platform design, fabrication, properties and functions. • The potential of SERS-based innovative nanohybrid platforms for food supply chain safety and security is discussed. Agri-food safety incidents not only threaten the life and health of consumers but also seriously hinder the development of the food supply chain. It is generally accepted that the development of rapid and reliable detection techniques ensures timely recognition and control of food hazards. Surface-enhanced Raman scattering (SERS) is a fast, sensitive, and fingerprinting vibrational spectroscopy with advantageous potentials for non-destructive and single-molecule detection of agri-food products. The physicochemical properties of SERS substrates determine the sensing performance and reliability of the detection methodology. However, traditional SERS substrates based on mono-noble metals exhibit poor sensing stability and limited specificity, not mentioning their poor availability and low cost-efficiency towards commercial industrialization. These intrinsic drawbacks hamper the use of noble metal SERS substrates for sensitive food detection in complicated scenes. With the emergence of various functional nanomaterials, the development of rationally designed and fabricated nanohybrid SERS platforms represents a promising frontier of SERS technology for highly sensitive, interference-free, multiplexed, and reliable food detection. Standing on the challenges and opportunities of SERS technology in food detection, this timely review firstly discloses the significance of function-oriented design and applications of versatile hybrid SERS substrates for addressing principal concerns in food detection and beyond. Thereafter, the various categories, hybridization strategies, and featured functionalities of the current hybrid SERS substrates have been well summarized in detail. Next, the advances in the application of hybrid SERS platforms for the detection and control of food supply chain safety factors have been fully reviewed and discussed. Finally, this review ended with a comprehensive and in-depth summary of the promising prospects and current challenges of nanohybrid SERS platforms in the agri-food industry. Overall, this contribution has demonstrated that nanohybridization endows SERS technique with desirable versatility beyond exquisite sensing performance, holding great promise for agri-food safety assurance. [ABSTRACT FROM AUTHOR]

Highlights • A facile synthesis of CDs-MoS 2 -Fe 3 O 4 nanohybrids was demonstrated. • CDs and Fe 3 O 4 afford synergetic effects on improving photocatalysis. • The excellent reusability and catalysis were achieved with a few materials (25 μg/ml). Abstract Herein, we demonstrate a facile synthesis of CDs-MoS 2 -Fe 3 O 4 nanohybrid composites as an efficient photocatalyst to enhance the removal of dyes from wastewater. Detailed characterization through SEM, TEM, EDAS, UV-vis, XRD, FT-IR and VSM confirmed the synthesis of thin MoS 2 nanosheets and the formation of the nanohybrid composites. As a result, CDs-MoS 2 -Fe 3 O 4 exhibits excellent reusability through magnetic separation and its degradation rate of methylene blue as high as 96.8% with few additions of materials (25 μg/ml). The ultrahigh photocatalytic performance and chemical stability, accompanied with this facile and simple synthetic process, promising CDs-MoS 2 -Fe 3 O 4 as a low-cost, ultrahigh-performance and robust photocatalyst in practical dyes degradation. [ABSTRACT FROM AUTHOR]

The grave threat posed by food hazards to food security and human health has increased the urgency of rapid and sensitive detection. Enzyme-mimic immune detection, particularly nanozyme-activated food immunosensors (NAFI), shows distinct specificity and catalytic properties, advancing food safety supervision. However, knowledge of the fundamental principles and functionalities of NAFI is still limited. Based on tracking the timeline of the independent evolution and combination of immunosensors and nanozymes, we first provide a systemic view to describe the trends of NAFI. Moreover, the underlying catalytic mechanisms are discussed according to classification in this review, including metal-based, carbon-based, and metal-organic framework-based nanozymes. In particular, significant attention is focused on the fundamental function of nanozyme receptors in food immunosensors, including the connection between nanozymes and bio-affinity ligands (one pot and two steps), signal modulation and amplification, and various signal outputs (typical and novel modes), which are crucial for gaining the best performance and further innovation. Finally, based on representative applications of nanozymes to detect food hazards, the main challenges in the development of NAFI are summarized, and future research directions for this highly prospective frontier are envisioned. • Nanozyme-activated food immunosensors (NAFI) are systematically discussed. • The history, category, and mechanism of NAFI are summarized. • Strategies for balancing nanozyme and antibody activities are summarized. • Both the typical signal mode and innovative signal mode are evaluated. • A perspective on the future trajectory of NAFI is provided. [ABSTRACT FROM AUTHOR]

• UiO-66(NH 2)@Au SERS platform with adsorbability and SERS-activity was synthesized. • New coccine and orange II were measured by SERS platform with satisfactory R2. • LOD was 0.4015 mg/L for new coccine and 0.0546 mg/L for orange II. • New coccine and orange II in food matrices were analyzed with acceptable recovery. Synthetic dyes have been widely applied to food processing, but abuse of colourants in food may pose risks to human health. To analyze new coccine (NC) and orange II (OII) in food, a versatile surface-enhanced Raman scattering (SERS) platform was proposed. A metal-organic framework (MOF, UiO-66(NH 2)) with octahedral crystal structure was synthesized and gold nanoparticles were grown on the MOF surface to fabricate UiO-66(NH 2)@Au versatile SERS platform. The UiO-66(NH 2)@Au displayed much better SERS performance than gold nanoparticles with high R2 of 0.9684 for NC and 0.9912 for OII and low LOD of 0.4015 mg/L for NC and 0.0546 mg/L for OII. The recoveries of NC and OII in Mirinda soft drink and paprika ranged from 82.92 to 109.63%. This study provided a sensitive and rapid method for determination of NC and OII through UiO-66(NH 2)@Au, and the proposed SERS platform revealed great potential for analyzing synthetic colourants in food samples. [ABSTRACT FROM AUTHOR]

As a rapid and facile means for foodborne bacteria detection in situ, lateral flow immunoassay (LFA) still has intrinsic limitations in the construction of the existing sandwich LFA format, e.g. screening difficulties of paired antibodies (Abs), poor stability of Ab probe, etc. Here, combined the strong affinity of antibiotic with the superior specificity of antibody molecules, a novel and robust LFA based on a dual recognition strategy and magnetic separation was designed to achieve specific and sensitive determination of Salmonella enteritidis (S. enteritidis). In this work, ampicillin (Amp), a broad-spectrum antibiotic against bacteria, was employed as an ideal Ab replacer to anchor cells of target bacteria. By coating Amp on magnetite nanoparticles (MNPs), the Amp-MNPs showed remarkable binding, separation and enrichment capacities toward bacteria even under complex sample matrices. To ensure the selectivity of this protocol, anti- S. enteritidis monoclonal antibody was then adopted as the second anchoring agent to form a sandwich complex with Amp-MNPs. Based on these facts, S. enteritidis , as low as 102–103 CFU/mL, could be detected by naked eyes in food samples. Therefore, this creative antibiotic-bacteria-antibody LFA sandwich pattern shows great application potential in the monitoring of food contamination and infectious diseases caused by pathogenic bacteria. Compared to the common paired Abs based sandwich method, the proposed approach was cost-effective, non-labor intensive, stable, sensitive and efficient. Image 1 • A DRS based, non-paired antibody dependent biosensor was constructed to detect S. enteritidis. • Ampicillin was introduced as an ideal Ab replacer to anchor S. enteritidis. • The Amp-MNPs was built as a recognition agent to capture and enrich bacteria. • The DRS-LFA possesses universal properties and can detection of other bacteria. [ABSTRACT FROM AUTHOR]

Highlights • Gram staining and direct immunoassay were first adopted for S. Enteritidis detection. • The marking signal was derived from one-step bacteria staining with crystal violet. • The device exhibited excellent sensitivity, simplicity, selectivity and feasibility. • Results could be clearly distinguished by naked eyes even under a lower analyte level. Abstract Here, a facile, label-free and sensitive lateral flow strip (LFS) biosensor for foodborne pathogens was established relying on the innovative introduction of Gram staining and the direct immunoreaction. Target bacteria can be directly marked with crystal violet (CV) by one-step staining which is superior to traditional signal marking techniques in LFS assay, and the method's selectivity can be guaranteed by high-specificity monoclonal antibody. With Salmonella Enteritidis (S. Enteritidis) as a model target, this protocol can selectively detect 80 CFU mL−1 S. Enteritidis within 11 min in the optimized conditions. Moreover, with Listeria monocytogenes as another model target, the biosensor shows a high universality for detections of both gram-negative and gram-positive bacteria. The unexpected applicability of biological dye tracer in strip biosensor reveals that the biological dye can be a potential tool serving as a universal signal tracer for pathogenic microorganisms in food safety monitoring and early clinical diagnosis. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A chemical-staining (crystal violet) based lateral flow immunoassay (LFIA) is first proposed for small molecule detection. • The developed LFIA significantly simplify the assay behavior and conquer the intrinsic limitations of nanomaterials labels. • The LFIA were successfully applied in several food samples for furazolidone detection. Abstract The nanomaterials based lateral flow immunoassays (LFIAs) have been widely used for on-site detection of small molecules contaminants. Nevertheless, their practical applications are often constrained by the complicated materials synthesis and surface modification process of nanomaterials. Herein, inspired by chemical-staining, a crystal violet (CV) staining based LFIAs was innovatively developed for the first time to analyze small molecules contaminant with significantly simplified behaviour and surpassing repeatability. This nanomaterials-free technique overcomes the intrinsic limitations of nanomaterials, owing to the superior protein dye property of CV. To demonstrate the feasibility of the unique strategy, furazolidone (FZD) was used as a model analyte, results showed detection limits of as low as 7 and 1.53 ng mL−1 by visual observation and quantitative analysis, respectively. Finally, to validate its applicability in actual conditions, the platform is well applied in three kinds of food samples (shrimp, fish and pork). Furthermore, as the detection principle is based on the molecular recognition between antigen and antibody, our method may find general applications by staining other antibodies against other target analytes. [ABSTRACT FROM AUTHOR]

Immunochromatographic assays (ICAs) are most frequently used for on-site rapid screening of clenbuterol. To improve sensitivity, a novel probe with bacteria as signal carriers was developed. Bacteria can load a great deal of gold nanoparticles (AuNPs) on their surface, meaning much fewer antibodies are needed to produce clearly visible results, although low concentrations of antibody could also trigger fierce competition between free analyte and the immobilized antigen. Thus, a limited number of antibodies was key to significantly improved sensitivity. Analytical conditions, including bacterial species, coupling method, and concentration, were optimized. The visual detection limit (VDL) for clenbuterol was 0.1 ng/mL, a 20-fold improvement in sensitivity compared with traditional strips. This work has opened up a new route for signal amplification and improved performance of ICAs. Furthermore, inactivated bacteria could also be environment-friendly and robust signal carriers for other biosensors. [ABSTRACT FROM AUTHOR]

We presented a signal amplified lateral flow assay (LFA) based on magnetite nanoparticles (MNPs) labeled dual-probe and applied it in the high sensitive and rapid on-site detection of furazolidone metabolite of 3-amino-2-oxazolidinone (AOZ). The amplified signal benefited from high affinity between two probes of MNPs labeled murine monoclonal antibody (MNPs-MAb) and goat anti-mouse antibody (MNPs-GAMA) and was achieved by the generation of dual-probe network complex. This developed method could realize high sensitive detection of AOZ with a threshold value of 0.88 ng mL −1 and a detection limit of 0.044 ng mL −1 , the sensitivity was at least 10-fold improved than that of the traditional gold nanoparticle based LFA. This facile developed assay was successfully applied for rapid detection of AOZ in milk samples. The proposed method paves a new way for on-site screening of other hazardous substances in food and can be referred in all lateral flow assays. [ABSTRACT FROM AUTHOR]

Photocatalytic disinfection, which is a readily reliable method in most climates, holds great promise to significantly reduce the microbial contamination in modern industry. Here we report that vanadate quantum dots-interspersed graphitic carbon nitride (vanadate QDs/g-C 3 N 4 ) can achieve efficient inactivation of Salmonella by harvesting a substantial visible light. Detailed characterization through SEM-EDS, TEM, XRD, FT-IR, and XPS confirmed the formation of the composites. Owing to the efficient reactive oxygen species (ROS) production between vanadate QDs and g-C 3 N 4 , the bactericidal efficiency of AgVO 3 QDs/g-C 3 N 4 could reach 96.4% toward Salmonella in a concentration of 0.75 mg/mL after 10 min visible-light illumination. More importantly, scavenger experiments of different reactive species proved that the photoinduced electron generated at the oxidation site of AgVO 3 /g-C 3 N 4 play a major role as oxidative species. Fluorescent-based cell live/dead test and membrane potentials were applied to demonstrate the integrity of cell membranes. Furthermore, the SEM technology, PCR and BCA protein assay were employed to verify the bacterial decomposition as well as leakage of bacterial cell contents toward Salmonella . Sterilization experiments of Staphylococcus aureus revealed that our composites have broad spectrum antimicrobial activity for both Gram-negative and Gram-positive bacteria under visible light. The results showed that the generation of high ROS could attack the bacterial cells membrane, and ultimately disrupt the cell metabolism through bacterial contents, which provided a feasible method for eliminating the microbial contaminated water. [ABSTRACT FROM AUTHOR]

Small molecules are difficult to detect by conventional gold lateral flow assay (GLFA) sensitively because the test system must satisfy the conflict requirements between enough signal intensity and limited antibody (Ab) amount. In this work, a paired labels recognition (PLR)-based biosensor was designed by utilizing the specific binding of Ab and secondary antibody (anti-Ab) to enhance signal intensity and reduce antibody amount applied in small molecule detection. The PLR amplification system is fabricated by self-assembling the common detection probe, Au-labeled Ab (Au-Ab), and the signal booster, Au-labeled anti-Ab (Au-anti-Ab). Benefiting from this, a powerful network structure can be generated to accumulate numerous gold nanoparticles (GNPs) and thus significantly strengthen the signal intensity of detection. Therefore, a lower Ab amount will be applied to offer adequate signal strength, and further, the limit of detection will be obviously downregulated due to the more effective competition reaction. Using furazolidone (FZD) as a model analyte, we achieve a detection limit of as low as 1 ng mL−1, which was at least fivefold improved over that of the traditional GLFA. Furthermore, the practicality of this strategy was certificated in five different food samples.A paired labels recognition (PLR) amplification system is fabricated by self-assembling the common detection probe, Au-labeled Ab (Au-Ab), and the signal booster, Au-labeled anti-Ab (Au-anti-Ab). In this novel strategy, owing to the recognition of both Ab and anti-Ab labeled on gold nanoparticles (GNPs), a powerful network structure can be generated to accumulate numerous GNPs and thus significantly strengthen the signal intensity of detection. [ABSTRACT FROM AUTHOR]

Although the salt-adjusted properties of nanomaterials have been extensively used for colorimetric assays of all kinds of analytes, their applications in the design of fluorescence sensor are very limited. Herein, a novel fluorescence aptasensor was developed for the sensitive determination of Bisphenol S (BPS) by the salt-adjusted fluorescence resonance energy transfer (FRET) between the zero-dimensional emitter (CQDs) and the two-dimensional absorber (MoS 2 nanosheets) and the roles of specific discrimination and protective effect of anti-BPS aptamer to layered MoS 2 . It is shown that layered MoS 2 can serve as a good fluorescent quencher towards carbon dots with decent quenching efficiency. Importantly, the established fluorescent method achieved satisfactory results for the determination of BPS with a good linear correlation from 0.05 μM to 2 μM and a detection limit of 2 nM. It is expected that this method may offer a new direction for the application of the phenomenon of salt-assisted aggregation of nanomaterials in designing high-performance fluorescent biosensors. [ABSTRACT FROM AUTHOR]

In order to resolve the pollution and waste caused by urea-rich wastewater, designing superior and stable earth-abundant catalysts for urea oxidation reaction (UOR) have always been attractive and urgent but still challenging. Herein, we report on a facile surface-engineering strategy of building hierarchical nickel hydroxide nanosheet@nanowire array on Ni foam (Ni(OH) 2 NS@NW/Ni foam) as anode material toward superior urea electrolysis. This Ni(OH) 2 based-catalyst with peculiar nanosheet@nanowire configuration just requires a small potential of 0.34 V ( vs. SCE) to drive 10 mA cm −2 in 1.0 M KOH with 0.33 M urea, which outperforms the one with pure nanosheet array architecture and even the commercial Pt/C catalyst. Further, a two-electrode electrolysis system is built here with the cathode of cobalt phosphide nanowire array on Ni foam (Co 2 P NW/Ni foam) and anode of Ni(OH) 2 NS@NW/Ni foam for overall urea electrolysis, which needs a low voltage of 1.58 V to drive 5 mA cm −2 in 1.0 M KOH with 0.33 M urea. Note that, the current density presented in this work is based on the real surface area of Ni foam but not the geometric area, unless otherwise specified. [ABSTRACT FROM AUTHOR]

A signal amplified lateral flow immunoassay (LFIA) based on gold nanoparticles (GNPs) growth and accumulation for rapid detection of Salmonella Enteritidis ( S. Enteritidis) was developed. The signal was amplified on account of the high catalytic activity of GNPs toward the reaction between HAuCl 4 and NH 2 OH·HCl, which could produce new GNPs on the surface of the initial GNPs. The remarkable enhanced signal at the test and control lines can be clearly distinguished by naked eyes even under a lower analyte level. The lowest visible detection limit of the signal enhanced LFIA for S. Enteritidis was as low as 10 4 CFU/mL with excellent specificity, achieving a 100-fold improvement in sensitivity compared to the traditional GNP-based LFIA. Finally, for applicability demonstration the method was applied to milk for S. Enteritidis analysis. Except for incubation time, the process required only 6 h, which was obvious shorter than that of many reported methods. [ABSTRACT FROM AUTHOR]

• Multifunctional Fe 3 O 4 @Au nanoflowers have been successfully synthesized. • Au-4MBA@Ag nanospheres with stable and strong SERS signal was prepared as SERS tag. • High-performance SERS aptasensor was successfully developed by aptamer recognition. • The ultralow detection limit of AFB1 was estimated to be 0.40 pg·mL−1. Aflatoxin B1 (AFB1) as the most toxic mycotoxin in contaminated food can greatly threaten human health, and sensitive and selective detection of AFB1 is thus highly desired. An ultrasensitive surface-enhanced Raman spectroscopy (SERS) aptasensor was developed for AFB1 detection in peanut oil samples. SH-cDNA modified Fe 3 O 4 @Au nanoflowers acted as capture probes, SH-Apt modified Au@Ag nanospheres and commercial Cy3-Apt were used as reporter probes. Strong SERS signals of reporter probes were produced due to the recognition of AFB1 aptamer and its complementary strand (SH-cDNA). With the preferred binding of AFB1 aptamer to AFB1, reporter probes were released from capture probes, causing a linear decrease in SERS intensity. Therefore an ultralow detection limit of 0.40 pg·mL−1 in a wide linear range of 0.0001–100 ng·mL−1 was obtained and the sensibility of this SERS aptasensor was higher than that of the Cy3-Apt based SERS aptasensor. In addition, an excellent selectivity in interfering toxins and satisfactory recoveries of 96.6–115% in peanut oil samples were obtained, proving this aptasensor is a promising analytical tool in AFB1 detection. [ABSTRACT FROM AUTHOR]

The authors describe a fluorometric method for the quantification of tannic acid (TA). MoO3-x quantum dots (QDs) can selectively capture TA via the formation of an organic molybdate complex. This causes an electron transfer effect and an inner filter effect to result in synergistic quenching of the fluorescence of the QDs. TA can be detected via this effect with a linear response in the of 0.1–10 μM concentration range and a lower detection limit of 30 nM within 1 min. The use of such QDs as a quenchable fluorescent probe warrants good selectivity even in the presence of relatively high concentration of potentially interferents and makes the method suitable for real sample analysis. Graphical abstract Tannic acid can be rapidly and selectively detected in food using a MoO3-x quantum dots based fluorometric assay. [ABSTRACT FROM AUTHOR]