Development of a single-chain variable fragment antibody-based enzyme-linked immunosorbent assay for determination of fumonisin B₁ in corn samples

Canine distemper virus (CDV)-neutralizing activities of an anti-CDV canine-derived single-chain variable antibody fragment 4-15 (scFv 4-15) screened by phage display technology

Canine distemper virus (CDV) is a highly contagious pathogen that causes severe diarrhea, fever and vomiting in domestic dogs, posing a serious threat to the dog breeding industry. Currently, there are no effective therapeutic agents for emergency treatment despite the availability of vaccines against CDV infection. Single-chain fragment variable (scFv) antibody has been demonstrated to effectively inhibit virus infections, suggesting a potential candidate as a therapeutic agent for canine distemper. In this study, a phage-displayed scFv library was constructed from the peripheral blood lymphocytes of dog immunized intramuscularly with live-attenuated CDV vaccine, and was subjected to four rounds of pannings against CDV. Subsequent indirect enzyme-linked immunosorbent assay screening revealed high-affinity scFv antibodies specific to CDV, and indirect immunofluorescence assay screening revealed CDV-neutralizing activity of scFv antibodies. Our results showed that a scFv antibody 4-15 (scFv 4-15) with high-affinity binding to CDV and neutralizing activity against CDV was obtained, which displayed effective therapeutic potential in vivo for dogs challenged with a lethal dose of CDV. Conclusively, the scFv 4-15 with high-affinity binding and neutralizing activity to CDV that was obtained by phage display technology provides a promising candidate for the therapeutic agents against CDV infection.

Rapid colorimetric sensor for ultrasensitive and highly selective detection of Fumonisin B1 in cereal based on laccase-mimicking activity of silver phosphate nanoparticles

Ag3PO4 nanoparticles (NPs) was prepared through a facile coprecipitation method, and was first found to have excellent laccase-mimicking catalytic activity. The study confirms that Fumonisin B1 (FB1) can effectively hinder the production of superoxide anion (O2-) between Ag3PO4 NPs and dissolved oxygen, and further inhibit laccase-mimicking activity of Ag3PO4 NPs. Thus, a novel rapid colorimetric sensor for FB1 analysis in cereal was first established using laccase-mimicking activity as sensing signal. The absorbance variation of sensing solution is directly related to the amount of FB1, and the color change is further combined with smartphone for quantitively analysis of FB1. The limit of detection (LOD) of the sensor is determined as low as 1.73 μg·L-1, which is far lower than the maximum residue limits (MRLs) of FB1 set by European Commission and US Food and Drug Administration (FDA). The average recovery of 87.8-104.5% for FB1 detection was obtained in cereal.

Overview-gold nanoparticles-based sensitive nanosensors in mycotoxins detection

Food-borne mycotoxins is one of the food safety concerns in the world. At present, nanosensors are widely used in the detection and analysis of mycotoxins due to their high specificity and sensitivity. In nanosensor-based mycotoxindetections, the sensitivity is mainly improved from two aspects. On the one hand, based on the principle of immune response, antigens and antibodies can be modified and developed. Such as single-domain heavy chain antibodies, aptamers, peptides, and antigen mimotopes. On the other hand, improvements and innovations have been made on signal amplification materials, including gold nanoparticles (AuNPs), quantum dots, and graphene, etc. Among them, gold nanoparticles can not only be used as a signal amplification material, but also can be used as carriers for identification elements, which can be used for signal amplification in detection. In this article, we systematically summarized the emerging strategies for enhancing the detection sensitivity of traditional gold nanoparticles-based nanosensors, in terms of recognition elements and signal amplification. Representative examples were selected to illustrate the potential mechanism of each strategy in enhancing the colorimetric signal intensity of AuNP and its potential application in biosensing. Finally, our review suggested the challenges and future prospects of gold particles in detection of mycotoxins.

Design of a new electrochemical aptasensor based on screen printed carbon electrode modified with gold nanoparticles for the detection of fumonisin B1 in maize flour

A new aptasensor for detecting fumonisin B1 (FB1) in the maize samples was developed based on DNA- aptamer recognition and electrochemical technique. A thiol-modified single-stranded DNA (ss-HSDNA) was immobilized on a screen printed carbon electrode (SPCE) electrodeposited by gold nanoparticles (AuNPs). The morphology and structure of SPCE and AuNPs/SPCE were evaluated via scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The SEM results demonstrated that the SPCE had a flat sheet-like structure, and the AuNPs were homogeneously electrodeposited on the SPCE. Cyclic voltammetry (CV) experiments in the [Fe(CN)₆]^- 3/- 4 solution were conducted to investigate each step of electrode modification as well as aptasensor performance. Aptamer-FB1 interaction prevented the electron transfer permitting the determination of FB1 in the range of 0.5-500 ng/mL with a low detection limit (0.14 ng/mL). The designed aptasensor was also shown high selectivity, acceptable repeatability and reproducibility, good long-term stability, and excellent recovery. Furthermore, there was a strong correlation between the findings achieved via the designed aptasensor and high performance liquid chromatography (HPLC). Therefore, a simple construction process and satisfactory electrochemical performance of the proposed aptasensor have a great potential for the detection of FB1 in maize samples.

Single-chain fragment variable produced by phage display technology: Construction, selection, mutation, expression, and recent applications in food safety

Immunoassays are reliable, efficient, and accurate methods for the analysis of small-molecule harmful substances (such as pesticides, veterinary drugs, and biological toxins) that may be present in food. However, traditional polyclonal and monoclonal antibodies are limited by animal hosts and hinder further development of immunoassays. With the gradual application of phage display technology as an efficient in vitro selection technology, the single-chain fragment variable (scFv) now provides an exciting alternative to traditional antibodies. Efficiently constructed scFv source libraries and specifically designed biopanning schemes can now yield scFvs possessing specific recognition capabilities. A rational mutation strategy further enhances the affinity of scFv, and allows it to reach a level that cannot be achieved by immunization. Finally, appropriate prokaryotic expression measures ensure stable and efficient production of scFv. Therefore, when developing excellent scFvs, it is necessary to focus on three key aspects of this process that include screening, mutation, and expression. In this review, we analyze in detail the preparation and affinity improvement process for scFv and provide insights into the research progress and development trend of scFv-based immunoassay methods for monitoring small-molecule harmful substances.

Development of Fluorescence Polarization Immunoassay With scFv to Detect Fumonisin Bs in Maize and Simultaneous Study of Their Molecular Recognition Mechanism

In this study, a fluorescence polarization immunoassay (FPIA) was developed based on the single-chain variable fragments (scFvs) for fumonisin B_s (FB_s). The scFvs were prepared from FB_s-specific monoclonal antibody secreting hybridomas (4F5 and 4B9). The established FPIA could determine the sum of fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) within a short time. The IC₅₀ of FPIA for the detection of FB₁ and FB₂ were 29.36 ng/ml and 1,477.82 ng/ml with 4F5 scFv, and 125.16 ng/ml and 30.44 ng/ml with 4B9 scFv, so the 4B9 scFv was selected for detection of FB₁ and FB₂ in maize samples with a limit of detection of 441.54 μg/kg and 344.933 μg/kg. The recoveries ranged from 84.7 to 104.1% with a coefficient of variation less than 14.1% in spiked samples, and the result of the FPIA method was in good consistency with that of HPLC-MS/MS. To supply a better understanding of the immunoassay results, the interactions mechanism of scFvs-FB_s was further revealed by the homology modelling, molecular docking, and molecular dynamic simulation. It was indicated that six complementarity-determining regions (CDRs) were involved in 4B9 scFv recognition, forming a narrow binding cavity, and FB₁/FB₂ could be inserted into this binding cavity stably through strong hydrogen bonds and other interactions. While in 4F5 scFv, only the FB₁ stably inserted in the binding pocket formed by four CDRs through strong hydrogen bonds, and FB₂ did not fit the binding cavity due to the lack of hydroxyl at C10, which is the key recognition site of 4F5 scFv. Also, the binding energy of FB₂-4B9 scFv complex is higher than the FB₂-4F5 scFv complex. This study established a FPIA method with scFv for the detection of FB₁ and FB₁ in maize, and systematically predicted recognition mechanism of FB_s and scFvs, which provided a reference for the better understanding of the immunoassay mechanism.

Extracellular production of azurin from Pseudomonas aeruginosa in the presence of Triton X-100 or Tween 80

Azurin which is a bacterial secondary metabolite has attracted much attention as potential anticancer agent in recent years. This copper-containing periplasmic redox protein supresses the tumor growth selectively. High-level secretion of proteins into the culture medium offers a significant advantage over periplasmic or cytoplasmic expression. The aim of this study was to investigate the effect of nonionic surfactants on the expression of the Pseudomonas aeruginosa azurin. Different concentrations of Triton X-100 and Tween 80 were used as supplements in growth media and extracellular azurin production was stimulated by both surfactants. According to western blot analysis results, in the presence of Triton X-100, maximum azurin expression level was achieved with 96 h of incubation at 1% concentration, and 48 h at 2% concentration. On the other hand, maximum azurin expression level was achieved in the presence of 1% Tween 80 at 72 h incubation. This study suggested for the first time a high level of azurin secretion from P. aeruginosa in the presence of Triton X-100 or Tween 80, which would be advantageous for the purification procedure.

Mimotopes for Mycotoxins Diagnosis Based on Random Peptides or Recombinant Antibodies from Phage Library

Mycotoxins, the small size secondary metabolites of fungi, have posed a threat to the safety of medicine, food and public health. Therefore, it is essential to create sensitive and effective determination of mycotoxins. Based on the special affinity between antibody and antigen, immunoassay has been proved to be a powerful technology for the detection of small analytes. However, the tedious preparation and instability of conventional antibodies restrict its application on easy and fast mycotoxins detection. By virtue of simplicity, ease of use, and lower cost, phage display library provides novel choices for antibodies or hapten conjugates, and lead random peptide or recombinant antibody to becoming the promising and environmental friendly immune-reagents in the next generation of immunoassays. This review briefly describes the latest developments on mycotoxins detection using M13 phage display, mainly focusing on the recent applications of phage display technology employed in mycotoxins detection, including the introduction of phage and phage display, the types of phage displayed peptide/recombinant antibody library, random peptides/recombinant antibodies-based immunoassays, as well as simultaneous determination of multiple mycotoxins.

Aptamer-based detection of fumonisin B1: A critical review

Mycotoxin contamination is a current issue affecting several crops and processed products worldwide. Among the diverse mycotoxin group, fumonisin B1 (FB1) has become a relevant compound because of its adverse effects in the food chain. Conventional analytical methods previously proposed to quantify FB1 comprise LC-MS, HPLC-FLD and ELISA, while novel approaches integrate different sensing platforms and fluorescently labelled agents in combination with antibodies. Nevertheless, such methods could be expensive, time-consuming and require experience. Aptamers (ssDNA) are promising alternatives to overcome some of the drawbacks of conventional analytical methods, their high affinity through specific aptamer-target binding has been exploited in various designs attaining favorable limits of detection (LOD). So far, two aptamers specific to FB1 have been reported, and their modified and shortened sequences have been explored for a successful target quantification. In this critical review spanning the last eight years, we have conducted a systematic comparison based on principal component analysis of the aptamer-based techniques for FB1, compared with chromatographic, immunological and other analytical methods. We have also conducted an in-silico prediction of the folded structure of both aptamers under their reported conditions. The potential of aptasensors for the future development of highly sensitive FB1 testing methods is emphasized.

Toxicant substitutes in immunological assays for mycotoxins detection: A mini review

Recurring mycotoxins contamination has posedaseriousthreatto food safety worldwide. Competitive immunoassays are widely used techniques for high-throughput mycotoxins detection in agricultural products and foods. However, the inevitable introduction of mycotoxin conjugates produced by chemical conjugation usually results in complicated by-products, large batch errors and threats to operators and environment. Biologically derived surrogates of mycotoxin conjugates or mycotoxin standards are renewable immunoreagents. They can serve the same function as the responding counterparts in the immunoassays. The substitute-based immunoassays exhibit satisfactory sensitivity, pose less health threats to operators and environment, and contribute to the standardization of immunoassays for mycotoxins. This review focuses on the current applications of substitute-based immunoassays, clarifies their underlying mechanisms and provides a careful comparison. Challenges and future prospects are discussed.

Production and characterization of a single-chain variable fragment antibody from a site-saturation mutagenesis library derived from the anti-Cry1A monoclonal antibody

There are plenty of applications of Cry1A toxins (Cry1Aa, Cry1Ab, Cry1Ac) in genetically modified crops, and it is necessary to establish corresponding detection methods. In this study, a single-chain variable fragment (scFv) with high affinities to Cry1A toxins was produced. First, the variable regions of heavy (V_H) and light chain (V_L) were amplified from hybridoma cell 5B5 which secrete anti-Cry1A monoclonal antibody (mAb) and then spliced into scFv-5B5 by overlap extension polymerase chain reaction (SOE-PCR). Subsequently, site-saturation mutagenesis was performed after homology modeling and molecular docking, which showed that asparagine³⁵, phenylalanine³⁶, isoleucine¹⁰⁴, tyrosine¹⁰⁵, and serine¹⁹⁶, respectively, located in V_H complementarity-determining region (CDR1 and CDR3) and V_L framework region (FR3) were key amino acid sites. Then, the mutagenesis scFv library (1.35 × 10⁵ CFU/mL) was constructed and a mutant scFv-2G12 with equilibrium dissociation constant (K_D) value of 9.819 × 10^-9 M against Cry1Ab toxin, which was lower than scFv-5B5 (2.025 × 10^-8 M) was obtained by biopanning. Then, enzyme-linked immunosorbent assay (ELISA) was established with limit of detection (LOD) and limit of quantitation (LOQ) of 4.6-9.2 and 11.1-17.1 ng mL^-1 respectively for scFv-2G12, which were lower than scFv-5B5 (12.4-22.0 and 23.6-39.7 ng mL^-1). Results indicated the promising prospect of scFv-2G12 used for the detection of Cry1A toxins.

Generation of single-chain Fv antibody fragments against Mu-2-related death-inducing gene in Escherichia coli

Mu-2-related death-inducing (MuD) gene is involved in apoptosis in tumor cells. Although we have previously produced mouse monoclonal antibodies (MAbs) that specifically recognize human MuD, the application scope of MuD MAbs was restricted due to their mouse origin. Therefore, we attempted the generation of single-chain variable fragment (scFv) against MuD. The heavy- and light-chain variable region genes from two MuD hybridomas were isolated by PCR and joined by DNA encoding a (Gly₄Ser₁)₃ linker. These scFv fragments were cloned into a phagemid vector and expressed as E-tagged fusion proteins in Escherichia coli HB2151. The reactivity of selected Abs was evaluated using ELISA. Selected MuDscFv Abs specifically recognized human MuD, retaining ~ 50% potency of the parent MAbs. MuDscFv-M3H9 recognized the middle region of MuD, while MuDscFv-C22B3 recognized a broad region. Intracellular expression of MuDscFvs-C22B3 protected cells from TRAIL-induced apoptosis. These MuDscFv Abs may help in the study of intracellular signaling pathway centered on MuD and of drug use target and points.

Electrochemical Immuno- and Aptasensors for Mycotoxin Determination

Modern analysis of food and feed is mostly focused on development of fast and reliable portable devices intended for field applications. In this review, electrochemical biosensors based on immunological reactions and aptamers are considered in the determination of mycotoxins as one of most common contaminants able to negatively affect human health. The characteristics of biosensors are considered from the point of view of general principles of bioreceptor implementation and signal transduction providing sub-nanomolar detection limits of mycotoxins. Moreover, the modern trends of bioreceptor selection and modification are discussed as well as future trends of biosensor development for mycotoxin determination are considered.

Competitive and noncompetitive immunoassays for the detection of benzothiostrobin using magnetic nanoparticles and fluorescein isothiocyanate-labeled peptides

Phage-displayed peptides have been proven to be powerful reagents for competitive and noncompetitive immunoassays. However, they are unconventional reagents, which greatly limit their analytical commercial applications and require additional reagents for detection. In this work, the peptides that specifically bind with anti-benzothiostrobin monoclonal antibody (mAb) or benzothiostrobin-mAb immunocomplex were synthesized and conjugated with fluorescein isothiocyanate (FITC) as substitutes of the phage-displayed peptides to avoid their shortcomings and extend their applications. Competitive and noncompetitive fluorescence immunoassays (FIAs) for benzothiostrobin were developed by mAb coupling with magnetic nanoparticles as concentration elements and peptides conjugated with FITC as tracers. Compared with enzyme-linked immunosorbent assays, the FIAs reduced the number of steps from 6 to 2 and analysis time from more than 5 to 1.2 h. The competitive FIA showed the half-maximal inhibition concentration (IC₅₀) of 16.8 ng mL^-1 and detection range (IC₁₀-IC₉₀) of 1.0-759.9 ng mL^-1, while the concentration of analyte producing 50% saturation of the signal (SC₅₀) and detection range (SC₁₀-SC₉₀) of noncompetitive FIA were 93.4 and 5.9-788.2 ng mL^-1, respectively. The average spiked recoveries were 68.33-98.50% and 73.33-96.67% for competitive and noncompetitive FIAs, respectively. The FIAs showed good correlation with high-performance liquid chromatography for the detection of benzothiostrobin in authentic samples. Graphical abstract Development of competitive and noncompetitive fluorescence immunoassays for benzothiostrobin by using monoclonal antibody coupling with magnetic nanoparticles as concentration elements and peptides conjugated with fluorescein isothiocyanate as tracers.

A novel nanobody and mimotope based immunoassay for rapid analysis of aflatoxin B1

Mimotopes could replace mycotoxins and their conjugates to develop immunoassay methods. The mimotopes obtained by phage display technology were mainly using monoclonal antibodies or polyclonal antibodies as targets. However, the mimotope of recombinant antibody has not been selected and applied to immunoassay for mycotoxin. The purpose of this study was to prove that an immunoassay for mycotoxin could be developed based on both recombinant antibody and its mimotope. Using aflatoxin B1 (AFB₁) as a model system, mimotopes of an aflatoxin nanobody Nb28 were screened by phage display. A rapid magnetic beads-based directed competitive ELISA (MB-dcELISA) was developed utilizing Nb28 and its mimotope ME17. The 50% inhibitory concentration and the detection limit of the MB-dcELISA were 0.75 and 0.13 ng/mL, respectively, with a linear range of 0.24-2.21 ng/mL. Further validation study indicated good recovery (84.2-116.2%) with low coefficient of variable (2.2%-15.9%) in spiked corn, rice, peanut, feedstuff, corn germ oil and peanut oil samples. The developed immunoassay based on nanobody and mimotope provides a new strategy for the monitoring of AFB₁ and other toxic small molecular weight compounds.

Affinity Biosensors for Detection of Mycotoxins in Food

This chapter reviews recent achievements in methods of detection of mycotoxins in food. Special focus is on the biosensor technology that utilizes antibodies and nucleic acid aptamers as receptors. Development of biosensors is based on the immobilization of antibodies or aptamers onto various conventional supports like gold layer, but also on nanomaterials such as graphene oxide, carbon nanotubes, and quantum dots that provide an effective platform for achieving high sensitivity of detection using various physical methods, including electrochemical, mass sensitive, and optical. The biosensors developed so far demonstrate high sensitivity typically in subnanomolar limit of detection. Several biosensors have been validated in real samples. The sensitivity of biosensors is similar and, in some cases, even better than traditional analytical methods such as ELISA or chromatography. We believe that future trends will be focused on improving biosensor properties toward practical application in food industry.

New biorecognition molecules in biosensors for the detection of toxins

Biological and synthetic recognition elements are at the heart of the majority of modern bioreceptor assays. Traditionally, enzymes and antibodies have been integrated in the biosensor designs as a popular choice for the detection of toxin molecules. But since 1970s, alternative biological and synthetic binders have been emerged as a promising alternative to conventional biorecognition elements in detection systems for laboratory and field-based applications. Recent research has witnessed immense interest in the use of recombinant enzymatic methodologies and nanozymes to circumvent the drawbacks associated with natural enzymes. In the area of antibody production, technologies based on the modification of in vivo synthesized materials and in vitro approaches with development of "display "systems have been introduced in the recent years. Subsequently, molecularly-imprinted polymers and Peptide nucleic acid (PNAs) were developed as an attractive receptor with applications in the area of sample preparation and detection systems. In this article, we discuss all alternatives to conventional biomolecules employed in the detection of various toxin molecules We review recent developments in modified enzymes, nanozymes, nanobodies, aptamers, peptides, protein scaffolds and DNazymes. With the advent of nanostructures and new interface materials, these recognition elements will be major players in future biosensor development.

Expression and Functional Properties of an Anti-Triazophos High-Affinity Single-Chain Variable Fragment Antibody with Specific Lambda Light Chain

Triazophos is a widely used organophosphorous insecticide that has potentially adverse effects to organisms. In the present study, a high-affinity single-chain variable fragment (scFv) antibody with specific lambda light chain was developed for residue monitoring. First, the specific variable regions were correctly amplified from a hybridoma cell line 8C10 that secreted monoclonal antibody (mAb) against triazophos. The regions were then assembled as scFv via splicing by overlap extension polymerase chain reaction. Subsequently, the recombinant anti-triazophos scFv-8C10 was successfully expressed in Escherichia coli strain HB2151 in soluble form, purified through immobilized metal ion affinity chromatography, and verified via Western blot and peptide mass fingerprinting analyses. Afterward, an indirect competitive enzyme-linked immunosorbent assay was established based on the purified anti-triazophos scFv-8C10 antibody. The assay exhibited properties similar to those based on the parent mAb, with a high sensitivity (IC50 of 1.73 ng/mL) to triazophos and no cross reaction for other organophosphorus pesticides; it was reliable in detecting triazophos residues in spiked water samples. Moreover, kinetic measurement using a surface plasmon resonance biosensor indicated that the purified scFv-8C10 antibody had a high affinity of 1.8 × 10(-10) M and exhibited good binding stability. Results indicated that the recombinant high-affinity scFv-8C10 antibody was an effective detection material that would be promising for monitoring triazophos residues in environment samples.

Development of a sensitive, competitive, indirect ELISA for the detection of fumonisin B1 in corn originating from Anhui province, China

Fumonisin B₁ (FB₁) is a secondary metabolite produced by Fusarium verticillioides or Fusarium proliferatum, which present in food and feed. It causes hazardous effects on human and animal health. A monoclonal antibody (mAb) against FB₁ was produced and a simple, reliable and sensitive, competitive, indirect enzyme-linked immunosorbent assay (ci-ELISA) for detection of FB₁ was developed and the experiment conditions were optimized. The coating concentration of FB₁-ovalbumin (FB₁-OVA) was 500 ng mL^-1, the action concentrations of anti-FB₁ mAb and goat anti-mouse IgG were 1.28 × 10⁴ and 1:5000, respectively. The 50% inhibitory concentration (IC₅₀) was 11 ng mL^-1, with a detectable range of 1.25-250 ng mL^-1, and a limit of determination (LOD) of 1.15 ng mL^-1. The cross-reactivity (CR) of the antibody against fumonisin B₂ (FB₂) was 60.4, and <1% against deoxynivalenol (DON), aflatoxin B₁ (AFB₁), ochratoxin A (OTA) or zearalenone (ZEN). In spiked samples (250 ng g^-1, 500 ng g^-1, 1000 ng g^-1), the mean recoveries ranged from 86.7 ± 5% to 102 ± 4%, and the coefficient of variation (CV) ranged from 3% to 10%. A survey of 96 corn samples from Bozhou, Fuyang, Bengbu, and Hefei, in Anhui province, China, was performed. Frequencies of FB₁ contamination were 83.3%, 95.8%, 20.8% and 91.7%, and the mean concentrations of positive samples were 0.702 μg kg^-1, 0.883 μg kg^-1, 0.074 μg kg^-1, and 0.276 μg kg^-1, respectively. The results of this study suggest that the ci-ELISA developed in this study can be used to identify FB₁ in corn, furthermore, further study is needed to investigate FB₁ contamination in food and feed to prevent its harmful health effects.

Progress in the development of immunoanalytical methods incorporating recombinant antibodies to small molecular weight biotoxins

Rapid immunoanalytical screening of food and environmental samples for small molecular weight (hapten) biotoxin contaminations requires the production of antibody reagents that possess the requisite sensitivity and specificity. To date animal-derived polyclonal (pAb) and monoclonal (mAb) antibodies have provided the binding element of the majority of these assays but recombinant antibodies (rAb) isolated from in vitro combinatorial phage display libraries are an exciting alternative due to (1) circumventing the need for experimental animals, (2) speed of production in commonly used in vitro expression systems and (3) subsequent molecular enhancement of binder performance. Short chain variable fragments (scFv) have been the most commonly employed rAb reagents for hapten biotoxin detection over the last two decades but antibody binding fragments (Fab) and single domain antibodies (sdAb) are increasing in popularity due to increased expression efficiency of functional binders and superior resistance to solvents. rAb-based immunochromatographic assays and surface plasmon resonance (SPR) biosensors have been reported to detect sub-regulatory levels of fungal (mycotoxins), marine (phycotoxins) and aquatic biotoxins in a wide range of food and environmental matrices, however this technology has yet to surpass the performances of the equivalent mAb- and pAb-based formats. As such the full potential of rAb technology in hapten biotoxin detection has yet to be achieved, but in time the inherent advantages of engineered rAb are set to provide the next generation of ultra-high performing binder reagents for the rapid and specific detection of hapten biotoxins.

Developments in mycotoxin analysis: an update for 2013-2014

This review highlights developments in the determination of mycotoxins over a period between mid-2013 and mid-2014. It continues in the format of the previous articles of this series, emphasising on analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes and zearalenone. The importance of proper sampling and sample preparation is briefly addressed in a dedicated section, while another chapter summarises new methods used to analyse botanicals and spices. As LC-MS/MS instruments are becoming more and more widespread in the determination of multiple classes of mycotoxins, another section is focusing on such newly developed multi-mycotoxin methods. While the wealth of published methods during the 12 month time span makes it impossible to cover every single one, this exhaustive review nevertheless aims to address and briefly discuss the most important developments and trends.