Cyclic peptide: a safe and effective alternative to synthetic aflatoxin B1-competitive antigens

Small Peptides in the Detection of Mycotoxins and Their Potential Applications in Mycotoxin Removal

Mycotoxins pose significant risks to humans and livestock. In addition, contaminated food- and feedstuffs can only be discarded, leading to increased economic losses and potential ecological pollution. Mycotoxin removal and real-time toxin level monitoring are effective approaches to solve this problem. As a hot research hotspot, small peptides derived from phage display peptide libraries, combinatorial peptide libraries, and rational design approaches can act as coating antigens, competitive antigens, and anti-immune complexes in immunoassays for the detection of mycotoxins. Furthermore, as a potential approach to mycotoxin degradation, small peptides can mimic the natural enzyme catalytic site to construct artificial enzymes containing oxidoreductases, hydrolase, and lyase activities. In summary, with the advantages of mature synthesis protocols, diverse structures, and excellent biocompatibility, also sharing their chemical structure with natural proteins, small peptides are widely used for mycotoxin detection and artificial enzyme construction, which have promising applications in mycotoxin degradation. This paper mainly reviews the advances of small peptides in the detection of mycotoxins, the construction of peptide-based artificial enzymes, and their potential applications in mycotoxin control.

Biotin-labelled peptidomimetic for competitive time-resolved fluoroimmunoassay of benzothiostrobin

In recent years, more and more functional peptide ligands have been identified from phage display libraries and served the immunoassay of small molecules. After the identification, the phage particle instead limits further application of peptide ligands, so it is of great significance to explore the peptide ligand as an independent detection reagent. In this work, the identified peptidomimetic of benzothiostrobin was synthesized and labelled with biotin, which was combined with Eu³⁺-labelled streptavidin to develop the peptide-based time-resolved fluoroimmunoassay (P-TRFIA). Under the optimal conditions, the half-maximum inhibitory concentration (IC₅₀) of proposed P-TRFIA is 3.63 ng mL^-1, which is similar to the TRFIA using phage-borne peptidomimetic and Eu³⁺-labelled anti-phage antibody (IC₅₀: 4.55 ng mL^-1), also more sensitive than previously reported immunoassays for benzothiostrobin. In addition, the proposed P-TRFIA shows excellent specificity and accuracy for analysis of spiked samples, and its detection results shows good consistency with high-performance liquid chromatography for the detection of environment and agro-products samples with unknown benzothiostrobin concentrations.

Recent Progress in Rapid Determination of Mycotoxins Based on Emerging Biorecognition Molecules: A Review

Mycotoxins are secondary metabolites produced by fungal species, which pose significant risk to humans and livestock. The mycotoxins which are produced from Aspergillus, Penicillium, and Fusarium are considered most important and therefore regulated in food- and feedstuffs. Analyses are predominantly performed by official laboratory methods in centralized labs by expert technicians. There is an urgent demand for new low-cost, easy-to-use, and portable analytical devices for rapid on-site determination. Most significant advances were realized in the field bioanalytical techniques based on molecular recognition. This review aims to discuss recent progress in the generation of native biomolecules and new bioinspired materials towards mycotoxins for the development of reliable bioreceptor-based analytical methods. After brief presentation of basic knowledge regarding characteristics of most important mycotoxins, the generation, benefits, and limitations of present and emerging biorecognition molecules, such as polyclonal (pAb), monoclonal (mAb), recombinant antibodies (rAb), aptamers, short peptides, and molecularly imprinted polymers (MIPs), are discussed. Hereinafter, the use of binders in different areas of application, including sample preparation, microplate- and tube-based assays, lateral flow devices, and biosensors, is highlighted. Special focus, on a global scale, is placed on commercial availability of single receptor molecules, test-kits, and biosensor platforms using multiplexed bead-based suspension assays and planar biochip arrays. Future outlook is given with special emphasis on new challenges, such as increasing use of rAb based on synthetic and naïve antibody libraries to renounce animal immunization, multiple-analyte test-kits and high-throughput multiplexing, and determination of masked mycotoxins, including stereoisomeric degradation products.

Mimotope-Based Immunoassays for the Rapid Analysis of Mycotoxin: A Review

Mycotoxins are toxic contaminants in foods and feeds that are naturally occurring and largely unavoidable. Determining their contents in these products is essential to protect humans from harm. Immunoassays of mycotoxins have been well-established because they are fast, sensitive, simple, and cost-effective. However, a major limitation of immunoassays is the requirement of toxic mycotoxins as competing antigens, standards, or competing tracers. Mimotopes are peptides or proteins that can specifically bind to antibodies and compete with analytes for binding sites by mimicking antigenic epitopes. They can be employed as substitutes for competing antigens, standards, or competing tracers to avoid use of mycotoxins. This review summarizes the production and functionalization of the two main kinds of mimotopes, mimic peptides and anti-idiotypic antibodies (Ab2), and their applications in rapid analysis of mycotoxins.

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.

Developments in mycotoxin analysis: an update for 2018-19

This review summarises developments on the analysis of various matrices for mycotoxins that have been published in the period from mid-2018 to mid-2019. Analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes, and zearalenone are covered in individual sections. Advances in sampling strategies are also discussed in a dedicated section. In addition, developments in multi-mycotoxin methods – including comprehensive mass spectrometric-based methods as well as simple immunoassays – are also reviewed. This critical review aims to briefly present the most important recent developments and trends in mycotoxin determination as well as to address limitations of the presented methodologies.