Detection Of Food Contaminants Research Articles

Highly sensitive SERS substrates with multi-hot spots for on-site detection of pesticide residues

Pesticide residues will be a huge threat to food security and ecological environment; therefore, there is an urgent need to achieve rapid and on-site detection of pesticide residues. Herein, a plasmonic substrate with multiple “hot spots” was fabricated by transferring three-dimensional (3D) Au nanoparticles (NPs) onto the polydimethylsiloxane (PDMS) membrane for highly sensitive surface-enhanced Raman scattering (SERS) detection of pesticide residues. In combination with 3D-FDTD simulations, high SERS enhancement (EF = 1.2 × 108) and high detection sensitivity (LOD = 6.3 × 10-10 M) were achieved, mainly due to the enhanced electromagnetic fields around the “hot spots”. Additionally, the PDMS-based SERS substrate held good transparency and flexibility, enabling conformal contact with non-planar surfaces and allowing the laser to penetrate the back of the analytes. Combined with a portable Raman spectrometer, the substrates holds great potential for rapid, high-sensitive, and on-site detection of contaminants in food, especially for the analyte on the nonplanar surfaces.

Dual-readout fluorescence quenching immunochromatographic test strips for highly sensitive simultaneous detection of chloramphenicol and amantadine based on gold nanoparticle-triggered photoluminescent nanoswitch control

Herein, a novel fluorescence quenching immunochromatographic test strip (FQICTS) for simultaneous detection of chloramphenicol (CAP) and amantadine (AMD) was developed on the basis of inner filter effect (IFE), with the combination of gold nanoparticles (AuNPs) and highly luminescent green-emitting gold nanoclusters (AuNCs) as the IFE quencher/donor pair. The AuNPs could quench the excitation light and emission light of AuNCs and achieve a high IFE efficiency due to dual spectral overlapping. Under optimal conditions, the “turn-on” mode of the AuNCs-based dual-readout FQICTS showed good linearity for CAP detection in chicken samples from 0.05 ng/g to 10 ng/g, with a limit of detection (LOD) of 0.043 ng/g. The linear range of AMD is 0.5–50 ng/g, with LOD of 0.45 ng/g. The visual LODs of CAP and AMD in “turn-on” mode were 200 and 10 times lower than that in “turn-off” mode, respectively. The “turn-on” mode of FQICTS showed high recovery for detecting CAP (82.5–94.5%) and AMD (81.9–110.7%) spiked into chicken samples. The performance and practicability of the established method were verified with commercial enzyme-immunoassay kits, and good correlations were observed. Overall, the newly developed AuNCs-based dual-readout FQICTS is a promising on-site screening tool for rapid, high-sensitivity detection of multiple food contaminants in practical applications.

Recent Progress on Single-Molecule Detection Technologies for Food Safety.

Rapid and sensitive detection technologies for food contaminants play vital roles in food safety. Due to the complexity of the food matrix and the trace amount distribution, traditional methods often suffer from unsatisfying accuracy, sensitivity, or specificity. In past decades, single-molecule detection (SMD) has emerged as a way to realize the rapid and ultrasensitive measurement with low sample consumption, showing a great potential in food contaminants detection. For instance, based on the nanopore technique, simple and effective methods for single-molecule analysis of food contaminants have been developed. To our knowledge, there has been a rare review that focuses on SMD techniques for food safety. The present review attempts to cover some typical SMD methods in food safety, including electrochemistry, optical spectrum, and atom force microscopy. Then, recent applications of these techniques for detecting food contaminants such as biotoxins, pesticides, heavy metals, and illegal additives are reviewed. Finally, existing research challenges and future trends of SMD in food safety are also tentatively proposed.

Recent advances in aptamer-based optical and electrochemical biosensors for detection of pesticides and veterinary drugs

Food contaminants are a threat to agriculture, the food chain, and consequently human health. Traditional analytical methods for food safety usually have limitations in achieving quick on-site detection of contaminants in large food samples. Hence, there is an urgent need to develop sensitive, simple, and reproducible methods for the on-site detection of food contaminants. Aptamer-based biosensors have attracted increasing attention owing to their superior performance, simplicity, and sensitivity. Among aptamer-based biosensors, optical and electrochemical biosensors have been constructed for the detection of pesticides and veterinary drugs, such as acetamiprid, organophosphorus pesticides, and various antibiotics, which are together the cause of serious food pollution. Food sample preparation techniques pertaining to testing contaminants in food samples by using those aptasensors are briefly discussed. Additionally, the various nanomaterials and nanocomposites used in the sensing platform are described, to show the good effect of the currently employed means of generating and amplifying sensing signals to improve sensitivity and accuracy of detection. This review provides an overview of the latest advances in the sensing principles of aptamer-based biosensors, such as fluorescent, colorimetric, and electrochemical measurement methods. Recently, using the subsistent aptamers with affinity for food contaminants, optical aptasensors play an important role in detection assays to achieve easier observation and operation with an inexpensive instrument, while electrochemical aptasensors have the advantage of being sensitive, accurate, and less time-consuming. These detection methods provide a meaningful reference for monitoring food safety. The advantages and challenges of aptamer-based biosensors for food contaminant detection are described.

Advances in Design Strategies of Multiplex Electrochemical Aptasensors.

In recent years, the need for simple, fast, and economical detection of food and environmental contaminants, and the necessity to monitor biomarkers of different diseases have considerably accelerated the development of biosensor technology. However, designing biosensors capable of simultaneous determination of two or more analytes in a single measurement, for example on a single working electrode in single solution, is still a great challenge. On the other hand, such analysis offers many advantages compared to single analyte tests, such as cost per test, labor, throughput, and convenience. Because of the high sensitivity and scalability of the electrochemical detection systems on the one hand and the specificity of aptamers on the other, the electrochemical aptasensors are considered to be highly effective devices for simultaneous detection of multiple-target analytes. In this review, we describe and evaluate multi-label approaches based on (1) metal quantum dots and metal ions, (2) redox labels, and (3) enzyme labels. We focus on recently developed strategies for multiplex sensing using electrochemical aptasensors. Furthermore, we emphasize the use of different nanomaterials in the construction of these aptasensors. Based on examples from the existing literature, we highlight recent applications of multiplexed detection platforms in clinical diagnostics, food control, and environmental monitoring. Finally, we discuss the advantages and disadvantages of the aptasensors developed so far, and debate possible challenges and prospects.

Nanozyme-Based Biosensors for Exogenous Contaminant Detection in Foods

: Abstract Food safety arising from exogenous contaminants has become a global concern. The development of simple, rapid and sensitive methods for effective detection and management of trace levels of exogenous contaminants has emerged as a hotspot, as well as the important priorities in food industry. Nanozymes that are defined as the emerging enzyme-like nanomaterials with robust catalytic activity, simple preparation, high stability, and low cost have been widely used in construction of biosensors for detection of hazardous contaminants in foods, greatly accelerating the advancement of food safety assay. In this review, we comprehensively summarize the recent advances of nanozyme-based biosensors, such as colorimetric, electrochemical, photoelectrochemical and surface-enhanced Raman spectroscopy-based sensors, over the past five years for the detection of various exogenous contaminants including mycotoxins, heavy metals, pesticides, antibiotics, pathogens and microcystins in foods. Beyond a highlight of the advantages and limitations in real-world application, we critically propose the current challenges and future trends of these biosensors for exogenous contaminant detection in foods to guarantee their quality and safety.

Mapping Aspergillus niger Metabolite Biomarkers for In Situ and Early Evaluation of Table Grapes Contamination.

The Aspergillus niger exometabolome was recently investigated using advanced gas chromatography in tandem with multivariate analysis, which allowed a metabolite biomarker pattern to be proposed. Microbial metabolomics patterns have gained enormous relevance, mainly due to the amount of information made available, which may be useful in countless processes. One of the great challenges in microbial metabolomics is related to applications in more complex systems of metabolomics information obtained from studies carried out in culture media, as complications may occur due to the dynamic nature of biological systems. Thus, the main objective of this research was to evaluate the applicability of the A. niger metabololite biomarkers pattern for in situ and early evaluation of table grapes contamination, used as study model. A. niger is a ubiquitous fungus responsible for food contamination, being reported as one of the main agents of the black mold disease, a serious post-harvest pathology of table grapes. This work included analysis from 1 day of growth time of pure A. niger cultures, A. niger cultures obtained from previously contaminated grapes, and finally, an in situ solid-phase microextraction (SPME) approach directly on previously contaminated table grapes. Supervised multivariate analysis was performed which revealed that after 1 day of inoculation it was possible to detect A. niger biomarkers, which can be extremely useful in making this type of method possible for the rapid detection of food contamination. The results obtained confirm the potential applicability of the pattern of A. niger biomarkers for early detection of the fungi (after 1 day of contamination), and may be further explored for access food susceptibility to fungi contamination, based on direct analysis of the food item.

Detection of 5-hydroxymethylfurfural based on split-DNAzyme assisted signal amplification via quartz crystal microbalance

5-hydroxymethylfurfural (HMF) is one of the food contaminants mainly formed by Maillard and caramelization reaction. Here, we developed a simple method to detect HMF based on split-DNAzyme assisted signal amplification via Quartz crystal microbalance. Firstly, two fragments of the split-DNAzyme (ESΙ and ESII) and AuNPs-ssDNA were prepared. In the absence of HMF, the amino group of ESΙ reacted with the aldehyde group of ESΙΙ by Schiff base condensation，which linked ESΙ and ESII as DNAzyme. With the help of Mg2+, this DNAzyme cleaved AuNPs-ssDNA, freeing the complementary sequence of capture DNA from the ssDNA. In the presence of the target HMF, the aldehyde group in its molecular structure preferred to react with ESΙ, which prevented the link of ESΙ and ESII. In this case, DNAzyme cannot be formed effectively and the ssDNA modified on AuNPs cannot be cleaved. Secondly, the capture DNA was immobilized on Au chip in the QCM chamber. Then, the intact AuNPs-ssDNA was introduced to hybridize with the capture DNA, resulted in a large frequency change (ΔF) of the QCM biosensor because of the huge increased mass of AuNPs. So, HMF can be detected based on the frequency change (ΔF) of the QCM biosensor. This QCM biosensor is more sensitive than previously reported methods, which provide a new direction for the analytical detection of HMF and other food contaminants.

A fluorescence aptasensor based on carbon quantum dots and magnetic Fe3O4 nanoparticles for highly sensitive detection of 17β-estradiol

Trace amounts of 17β-estradiol (E2) in food and the environment poses a threat to human health, which has created the demand for sensitive analytical methods to detect E2. In this study, a novel fluorescent aptasensor was developed for sensitive detection of E2 based on double-chain hybridization between carbon quantum dots-labelled with E2 aptamer (CQDs-aptamer) and Fe3O4 nanoparticles modified by complementary DNA (Fe3O4-cDNA). Under the optimal conditions, the aptasensor displayed a good linear range of 10-11–10-6 M for E2 with the coefficient of determination (R2) of 0.996, and a low detection limit of 3.48 × 10-12 M was obtained. Besides, the aptasensor showed high selectivity and good reproducibility for E2 detection, which was successfully applied to the sensitive detection of E2 in milk as compared with tap water and lake water with satisfactory recoveries from 85.21% to 114.80%, suggesting the great significance of this aptasensor for detecting food contaminants in the food industry.

Construct high-precise SERS sensor by hierarchical superhydrophobic Si/Cu(OH)2 platform for ultratrace detection of food contaminants

Construction of the high-quality noble metal nanoparticle cluster (NMNPC) with big size for surface-enhanced Raman spectrum is still a challenge nowadays, due to its difficulty in integration of the uniformity, repeatability and sensibility. To realize this goal, a superhydrophobic platform composed of hierarchical Si/Cu(OH)2 nanowires with stable Cassie state was designed and prepared in this work. The optimal Ag NPC region is larger than 0.6 mm × 0.6 mm, and the limit of detection and relative standard deviation of it are respectively 2 × 10−18 M and 13.85%, indicating the fine SERS performance of it. Finite difference time domain simulations and systematic experimental analysis were made in detail here to figure out the underlying mechanism behind these phenomena. Furthermore, as a proof of concept, the Ag NPC was proved as an outstanding food contaminant sensor and successfully realized an ultratrace detection of both melamine in milk and malachite green on fish surface (ca 10−15 M, approaching to single-molecule level). This work provides a new way in constructing high-performance SERS substrate and shows promising application prospect in food safety inspection.

Preparation and electrochemical properties of MXene based conductive composites for food contamination detection

MXene has unique intercalation structure, excellent interlayer spacing and excellent biocompatibility. It is considered as an excellent nano material carrier and can be used as a good adsorbent in the detection of food pollutants. In this study, a large number of experimental materials and reagents were selected to prepare Co3O4 / MXene composites by in-situ growth of Co3O4 nanoparticles on MXene support by impregnation pyrolysis. The composite retained the original accordion like intercalation structure. The size and number of Co3O4 particles on the surface of MXene and in the intercalation increased with the increase of loading, showing regular order. The prepared composite has abundant lithium intercalation active sites, fast electron and ion transport channels, good rate performance and energy density at high current density, showing excellent electrochemical performance.

Semi-sacrificial template growth-assisted self-supporting MOF chip: A versatile and high-performance SERS sensor for food contaminants monitoring

Surface-enhanced Raman scattering (SERS) with its outstanding performance in ultra-sensitivity has been applied in contaminants monitoring. Herein, a facile strategy of integrating oriented layered MOF nanoarray with controlled electrodeposition of gold nanoparticles via semi-sacrificial template method was proposed to fabricate a versatile self-supporting MOF chip (S-MOF@Au) for efficient SERS detection of food contaminants. The S-MOF was ingeniously formed by directly using flexible Ni sheet as both metal source and scaffold, which in favour of greatly improving intrinsic electrical conductivity during electrodeposition process as well as endowing prepared chip with uniform distribution of gold nanoparticles and high stability. Furthermore, amounts of SERS “hot spots” in the oriented layered S-MOF@Au can yield strong electromagnetic field for Raman amplification with superior reproducibility. By virtue of good flexibility and pre-concentration effect of S-MOF@Au, tartrazine (TA), chloramphenicol (CP), imidacloprid (IDP) and crystal violet (CV) in food samples were sensitively detected using three collected approaches (drip coating, soaking and wiping) with low limits of detection (1.0 × 10−9 M for TA, 8.0 × 10−11 M for CP, 6.4 × 10−11 M for IDP and 5.0 × 10−12 M for CV), wide linear detection ranges (1.0 × 10−8 – 1.0 × 10−3 M for TA, 1.0 × 10−10 – 1.0 × 10−6 M for CP, 1.0 × 10−10 – 1.0 × 10−7 M for IDP and 1.0 × 10−11 – 1.0 × 10−7 M for CV) and satisfactory recoveries (96.2 – 125.1%). This method provides a novel strategy to develop an advanced SERS platform for efficient food contaminants monitoring.

Monitoring Food Contamination in Real Time Using Printable Dnazyme Sensors

Foodborne illnesses have a pronounced impact on the global community, with cases numbering into the hundreds of millions annually and associated treatments costing tens of billions of dollars. Our inability to commercially detect food contamination in real-time is at the center of this crisis, as it places emphasis on static expiry dates that lack accuracy. These predicted dates not only fail to convey contamination, but also result in the disposal of mass amounts of edible food products. When contaminants are retroactively detected, measures such as food recalls are logistically complex and have massive economic ramifications. Existing methods for real-time detection of contaminants are expensive, require sophisticated equipment or offer poor detection capabilities, thus preventing commercialization. Additionally, detection requires packaging to be opened, making it unfeasible to monitor food products on an individual basis. Here, we propose a detection system centered upon the covalent immobilization of pathogen-specific RNA-cleaving fluorescent deoxyribozymes (RFDs) onto food wraps for real-time pathogen detection. These biomolecules exhibit a significant increase in fluorescence when exposed to their respective target. By functionalizing food wrap materials through plasma treatment, suitable crosslinkers can be used to bind amine modified RFDs onto the bulk wrap material. In particular, carbon dioxide plasma paired with carbodiimide chemistry presents itself as a well-studied immobilization approach that is applicable within the proposed sensing platform. Additionally, the use of microcontact printing to pattern RFD-crosslinker solutions onto food wraps presents a strategy suitable for industry scale-up. Given the transparency of food wrap materials and the printed sensor, this platform also overcomes the current need to open packaging for pathogen detection. Ultimately, we envision a patterned RFD barcode that provides multiplex detection of common foodborne pathogens. Use of a handheld fluorescence reader would allow for inexpensive, portable detection of food contamination along the entirety of the food production pipeline.

Comprehensive Strategy for Sample Preparation for the Analysis of Food Contaminants and Residues by GC-MS/MS: A Review of Recent Research Trends.

Food safety and quality have been gaining increasing attention in recent years. Gas chromatography coupled to tandem mass spectrometry (GC–MS/MS), a highly sensitive technique, is gradually being preferred to GC–MS in food safety laboratories since it provides a greater degree of separation on contaminants. In the analysis of food contaminants, sample preparation steps are crucial. The extraction of multiple target analytes simultaneously has become a new trend. Thus, multi-residue analytical methods, such as QuEChERs and adsorption extraction, are fast, simple, cheap, effective, robust, and safe. The number of microorganic contaminants has been increasing worldwide in recent years and are considered contaminants of emerging concern. High separation in MS/MS might be, in certain cases, favored to sample preparation selectivity. The ideal sample extraction procedure and purification method should take into account the contaminants of interest. Moreover, these methods should cooperate with high-resolution MS, and other sensitive full scan MSs that can produce a more comprehensive detection of contaminants in foods. In this review, we discuss the most recent trends in preparation methods for highly effective detection and analysis of food contaminants, which can be considered tools in the control of food quality and safety.

Layer-by-Layer Assembly of Polystyrene/Ag for a Highly Reproducible SERS Substrate and Its Use for the Detection of Food Contaminants.

Polystyrene (PS) spheres were prepared through an emulsifier-free emulsion polymerization method, in which the reaction time, ionic strength, concentrations of copolymer were studied in detail. The resulting PS microspheres and Ag nanoparticles were used to construct a surface enhanced Raman scattering (SERS) substrate by a layer-by-layer assembly method. A relatively uniform distribution of PS/Ag in the films was obtained, and the multilayer substrate presented excellent SERS reproducibility and a tunable enhancement effect. The SERS substrate was used for detecting harmful pesticides (malachite green and dimetridazole) in food samples, with a limit of detection as low as 3.5 ppb. The obtained plasmonic composite has a promising future in the field of SERS sensing.

Applications of Adductomics in Chemically Induced Adverse Outcomes and Major Emphasis on DNA Adductomics: A Pathbreaking Tool in Biomedical Research.

Adductomics novel and emerging discipline in the toxicological research emphasizes on adducts formed by reactive chemical agents with biological molecules in living organisms. Development in analytical methods propelled the application and utility of adductomics in interdisciplinary sciences. This review endeavors to add a new dimension where comprehensive insights into diverse applications of adductomics in addressing some of society’s pressing challenges are provided. Also focuses on diverse applications of adductomics include: forecasting risk of chronic diseases triggered by reactive agents and predicting carcinogenesis induced by tobacco smoking; assessing chemical agents’ toxicity and supplementing genotoxicity studies; designing personalized medication and precision treatment in cancer chemotherapy; appraising environmental quality or extent of pollution using biological systems; crafting tools and techniques for diagnosis of diseases and detecting food contaminants; furnishing exposure profile of the individual to electrophiles; and assisting regulatory agencies in risk assessment of reactive chemical agents. Characterizing adducts that are present in extremely low concentrations is an exigent task and more over absence of dedicated database to identify adducts is further exacerbating the problem of adduct diagnosis. In addition, there is scope of improvement in sample preparation methods and data processing software and algorithms for accurate assessment of adducts.

Nanozyme Applications: A Glimpse of Insight in Food Safety.

Nanozymes own striking merits, including high enzyme-mimicking activity, good stability, and low cost. Due to the powerful and distinguished functions, nanozymes exhibit widespread applications in the field of biosensing and immunoassay, attracting researchers in various fields to design and engineer nanozymes. Recently, nanozymes have been innovatively used to bridge nanotechnology with analytical techniques to achieve the high sensitivity, specificity, and reproducibility. However, the applications of nanozymes in food applications are seldom reviewed. In this review, we summarize several typical nanozymes and provide a comprehensive description of the history, principles, designs, and applications of nanozyme-based analytical techniques in food contaminants detection. Based on engineering and modification of nanozymes, the food contaminants are classified and then discussed in detail via discriminating the roles of nanozymes in various analytical methods, including fluorescence, colorimetric and electrochemical assay, surface-enhanced Raman scattering, magnetic relaxing sensing, and electrochemiluminescence. Further, representative examples of nanozymes-based methods are highlighted for contaminants analysis and inhibition. Finally, the current challenges and prospects of nanozymes are discussed.

Recombinant antibodies and their use for food immunoanalysis.

Antibodies are widely employed as biorecognition elements for the detection of a plethora of compounds including food and environmental contaminants, biomarkers, or illicit drugs. They are also applied in therapeutics for the treatment of several disorders. Recent recommendations from the EU on animal protection and the replacement of animal-derived antibodies by non-animal-derived ones have raised a great controversy in the scientific community. The application of recombinant antibodies is expected to achieve a high growth rate in the years to come thanks to their versatility and beneficial characteristics in comparison to monoclonal and polyclonal antibodies, such as stability in harsh conditions, small size, relatively low production costs, and batch-to-batch reproducibility. This review describes the characteristics, advantages, and disadvantages of recombinant antibodies including antigen-binding fragments (Fab), single-chain fragment variable (scFv), and single-domain antibodies (VHH) and their application in food analysis with especial emphasis on the analysis of biotoxins, antibiotics, pesticides, and foodborne pathogens. Although the wide application of recombinant antibodies has been hampered by a number of challenges, this review demonstrates their potential for the sensitive, selective, and rapid detection of food contaminants.Graphical abstract

Research Progress on Detection Methods of Contaminants in Food Based on Fluorescence Immunoassay

In recent years, there’s a trend that the maximum limit of food contaminant is decreasing. Therefore, the development of more rapid and sensitive methods for the detection of food contaminants is a great requirement. Fluorescence immunoassay is one of the current fastest developing detection methods, which has been widely applied in the detection of various food contaminants and other fields. It has the advantage of high sensitivity, fast detection speed, simple operation, satisfactory accuracy, etc. This review offers an overview of fluorescence-immunoassay-based methods for the detection of contaminants in food based on different fluorescent labeling materials. Three types of common fluorescent labeling materials (including ordinary fluorescent microspheres, quantum dots and time-resolved fluorescent materials) and three types of new fluorescent labeling materials (containing up-conversion luminescence nanomaterials, magnetic fluorescent nanomaterials and fluorescent proteins) are introduced with the comparison in their optical features and analytical performance. In additon, the detection methods of contaminants in food based on fluorescence immunoassay (FIA) are introduced, the latest progress of fluorescence immunoassay in food contaminants detection is also summarized.

The Role of Aryldiazonium Chemistry in Designing Electrochemical Aptasensors for the Detection of Food Contaminants.

Food safety monitoring assays based on synthetic recognition structures such as aptamers are receiving considerable attention due to their remarkable advantages in terms of their ability to bind to a wide range of target analytes, strong binding affinity, facile manufacturing, and cost-effectiveness. Although aptasensors for food monitoring are still in the development stage, the use of an electrochemical detection route, combined with the wide range of materials available as transducers and the proper immobilization strategy of the aptamer at the transducer surface, can lead to powerful analytical tools. In such a context, employing aryldiazonium salts for the surface derivatization of transducer electrodes serves as a simple, versatile and robust strategy to fine-tune the interface properties and to facilitate the convenient anchoring and stability of the aptamer. By summarizing the most important results disclosed in the last years, this article provides a comprehensive review that emphasizes the contribution of aryldiazonium chemistry in developing electrochemical aptasensors for food safety monitoring.