Multiclonal plastic antibodies for selective aflatoxin extraction from food samples

Mycotoxins-Imprinted Polymers: A State-of-the-Art Review

Mycotoxins are toxic metabolites of molds which can contaminate food and beverages. Because of their acute and chronic toxicity, they can have harmful effects when ingested or inhaled, posing severe risks to human health. Contemporary analytical methods have the sensitivity required for contamination detection and quantification, but the direct application of these methods on real samples is not straightforward because of matrix complexity, and clean-up and preconcentration steps are needed, more and more requiring the application of highly selective solid-phase extraction materials. Molecularly imprinted polymers (MIPs) are artificial receptors mimicking the natural antibodies that are increasingly being used as a solid phase in extraction methods where selectivity towards target analytes is mandatory. In this review, the state-of-the-art about molecularly imprinted polymers as solid-phase extraction materials in mycotoxin contamination analysis will be discussed, with particular attention paid to the use of mimic molecules in the synthesis of mycotoxin-imprinted materials, to the application of these materials to food real samples, and to the development of advanced extraction methods involving molecular imprinting technology.

AFB1 recognition from liver tissue via AFB1 imprinted magnetic nanoparticles

Aflatoxins (AFs) are produced mainly by Aspergillus flavus and Aspergillus parasiticus and aflatoxin B1 (AFB1) is one of the most toxic aflatoxins with its carcinogenic property. AFB1 recognition from samples is very important and PHEMA based AFB1 imprinted magnetic nanoparticles (magAFB1-MIPs) were synthesized for the selective AFB1 recognition from liver tissue. The AFB1-MIPs were synthesized in different mole ratios and NIPs were synthesized for control. Characterization studies of magAFB1-MIPs and NIPs were carried out by swelling tests, surface area measurements, scanning electron microscopy and particle size analysis. The surface area was found as 117 m²/g and the size of the nanoparticles were found as 483 nm in diameter. The percentage yield of polymerization was calculated as 98 % and the template (AFB1) removal ratio from the magAFB1-MIPs was calculated as 91 %. The maximum adsorbtion capacities were calculated as 427.57 ng g^-1 for magAFB1-MIPs and 44.6 ng g^-1 for magNIPs. Selectivity tests showed that magAFB1-MIPs adsorb AFB1 1.74, 4.40, 2.46 times selective than that of AFB2, AFG1 and AFG2 molecules, respectively. AFB1 removal amount from AFB1 spiked liver tissue was satisfactory and recorded as 10.4 ng g^-1 and 54.8 ng g^-1 for 2 ng g^-1 and 10 ng g^-1 spiked liver tissue samples, respectively. AFB1 adsorption amount decrease was found negligible for 10 consecutive adsorption-desorption repeats in reusability study.

Molecularly imprinted polymers in toxicology: a literature survey for the last 5 years

The science of toxicology dates back almost to the beginning of human history. Toxic chemicals, which are encountered in different forms, are always among the chemicals that should be investigated in criminal field, environmental application, pharmaceutic, and even industry, where many researches have been carried out studies for years. Almost all of not only drugs but also industrial dyes have toxic side and direct effects. Environmental micropollutants accumulate in the tissues of all living things, especially plants, and show short- or long-term toxic symptoms. Chemicals in forensic science can be known by detecting the effect they cause to the body with the similar mechanism. It is clear that the best tracking tool among analysis methods is molecularly printed polymer-based analytical setups. Different polymeric combinations of molecularly imprinted polymers allow further study on detection or extraction using chromatographic and spectroscopic instruments. In particular, methods used in forensic medicine can detect trace amounts of poison or biological residues on the scene. Molecularly imprinted polymers are still in their infancy and have many variables that need to be developed. In this review, we summarized how molecular imprinted polymers and toxicology intersect and what has been done about molecular imprinted polymers in toxicology by looking at the studies conducted in the last 5 years.

Preparation of lysozyme loaded gelatin microcryogels and investigation of their antibacterial properties

Antibacterial micron-sized cryogels, so-called microcryogels, were prepared by cryogelation of gelatin and integration of lysozyme. Gelation yield, specific surface area, macro-porosity and swelling degree of the microcryogels were examined in order to characterize their physical properties. MTT method was utilized to measure cell viability of the gelatin microcryogels with a period of 24, 48, and 72 h and no significant decrease was observed at 72 h. Apoptotic staining assay also showed high viability at 24, 48, 72 h in parallel with the control group. The antibacterial performances of the gelatin microcryogels against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli were examined. The results showed that the incorporation of lysozyme into gelatin microcryogels exhibited the antibacterial activity against S. aureus, B. subtilis, and E. coli, that may provide great potential for various applications in the biomedical industry.

A nanozyme-linked immunosorbent assay based on metal-organic frameworks (MOFs) for sensitive detection of aflatoxin B1

In order to avoid the occurrence of false positives and false negatives caused by conventional enzyme-linked immunosorbent assay (ELISA), we established a novel indirect competitive MOF-linked immunosorbent assay (MOFLISA) method for the high throughput and high sensitive detection of aflatoxin B₁. This method replaces the natural enzyme with functional MOFs to catalyze a chromogenic system. As a result, the limit of detection (LOD) of the MOFLISA method was 0.009 ng·mL^-1 with a linear working range from 0.01 to 20 ng·mL^-1. The developed MOFLISA method for AFB₁ has a 20-fold improved LOD value compared with the conventional ELISA. The recoveries and relative standard deviations (RSD) ranged from 86.41 to 99.74% and 2.38-9.04%, respectively. The results demonstrate that the recovery rate and accuracy of this detection method is better than that of conventional ELISA, reducing risks offalsepositive andfalsenegativeresults.

Comparative evaluation of aflatoxin and mineral binding activity of molecular imprinted polymer designed for dummy template using in vitro and in vivo models

The amelioration of aflatoxicosis in ducklings was examined by feeding molecular imprinted polymer (MIP) synthesized to target the aflatoxin B₁ (AFB₁) analog molecule [5, 7-dimethoxycoumarin (DMC)] as a smart and novel toxin binder in comparison to a commercial toxin binder (CTB). MIP was characterized with some techniques, such as scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) that showed morphology and thermal resistance of MIP, respectively. The SEM showed that more pores and big cavities were formed in the network of the MIP. TGA plots of MIP showed dehydration at temperatures of about 31 °C-200 °C and gradual decomposition until 300 °C. The in vitro and in vivo ability of MIP and CTB to adsorb some minerals (Ca, Cu, Mg, P and Zn) was evaluated. The in vivo efficacy of MIP as an aflatoxins (AFs) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 d of age was also compared to that of the CTB. A total of 240 4-d-old ducklings were assigned to experimental diets. Each diet was replicated four times with 10 birds in each pen, and the initial body weight classes were considered as blocks. The experimental treatment diets included: 1- Control (basal diet without any additive or AFs), 2- MIP (5 g/kg diet), 3- CTB (5 g/kg diet), 4- AFs (0.2 mg/kg diet), 5- AFs + MIP (0.2 mg/kg + 5 g/kg diet), and 6- AFs + CTB (0.2 mg/kg + 5 g/kg diet). In vitro study may clearly reflect the possibility of adsorbing minerals by CTB as compared to MIP whilst the results were not confirmed by in vivo study and it seems that reduction in plasma levels of minerals is related to the adverse effects of AFs. Livers showed histopathological alterations, with bile-duct proliferation of all aflatoxin fed ducklings. Macroscopic study indicated liver of birds fed diets containing AFs showed abnormal signs including yellowish, friable and rounded shape without protective effect of MIP and CTB. The results obtained from in vivo study indicate the partial alleviation of the adverse effects of AFs in ducklings by dietary supplementation of MIP and CTB (5 g/kg) on plasma albumin, Zn, Mg and Ca.

The first in vivo application of synthetic polymers based on methacrylic acid as an aflatoxin sorbent in an animal model

This study attempts to evaluate the potential aflatoxin binder activity of a molecularly imprinted polymer (TMU95) synthesized to target the aflatoxin B₁ (AFB₁) analog molecule in comparison to a commercial toxin binder (CTB). Adsorption experiments were carried out to assess the ability to bind to AFB₁ at various pH values. The strength of binding was investigated by the chemisorption index. The isothermal analysis was used to determine the maximum adsorption capacity values. The ability of TMU95 and CTB to adsorb essential minerals was evaluated and the obtained data suggested that CTB would significantly reduce availability of them compared to TMU95. The in vivo efficacy of TMU95 as an aflatoxin (AF) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 days of age in comparison to the CTB was also assessed. TMU95 and CTB were effective in reducing the adverse effects caused by AFs on feed conversion ratio of duckling (p ≤ 0.01), and also showed a minor reduction of injuries caused by AFs on visceral organs enlargement (p ≤ 0.01). It was concluded that TMU95 could absorb AFB₁ in vitro efficiently and had beneficial health effects that could alleviate some of the toxic effects of AFs on growing duckling performance similar to CTB.

Newest applications of molecularly imprinted polymers for extraction of contaminants from environmental and food matrices: A review

This paper presents an overview of the recent applications of molecularly imprinted polymers (MIPs) to sample preparation. The review is thought to cover analytical procedures for extraction of contaminants (mainly illegal/noxious organic compounds) from food and environmental matrices, with a particular focus on the various pre-concentration/cleanup techniques, that is offline and online solid-phase extraction (SPE), dispersive SPE (d-SPE), magnetic SPE (MSPE), solid-phase microextraction (SPME) and stir-bar sorptive extraction (SBSE), applied before instrumental quantification. The selectivity and extraction efficiency of MIP-based sorbent phases are critically discussed, also in relation to the physical-chemical properties resulting from the synthetic procedures. A variety of molecularly imprinted sorbents is presented, including hybrid composites embedding carbon nanomaterials and ionic liquids. The analytical performance of MIP materials in sample preparation is commented as function of the complexity of the matrix, and it is compared to that exhibited by (commercial) aspecific and/or immunosorbent phases.

Molecular Imprinting Applications in Forensic Science

Producing molecular imprinting-based materials has received increasing attention due to recognition selectivity, stability, cast effectiveness, and ease of production in various forms for a wide range of applications. The molecular imprinting technique has a variety of applications in the areas of the food industry, environmental monitoring, and medicine for diverse purposes like sample pretreatment, sensing, and separation/purification. A versatile usage, stability and recognition capabilities also make them perfect candidates for use in forensic sciences. Forensic science is a demanding area and there is a growing interest in molecularly imprinted polymers (MIPs) in this field. In this review, recent molecular imprinting applications in the related areas of forensic sciences are discussed while considering the literature of last two decades. Not only direct forensic applications but also studies of possible forensic value were taken into account like illicit drugs, banned sport drugs, effective toxins and chemical warfare agents in a review of over 100 articles. The literature was classified according to targets, material shapes, production strategies, detection method, and instrumentation. We aimed to summarize the current applications of MIPs in forensic science and put forth a projection of their potential uses as promising alternatives for benchmark competitors.