Aflatoxin B1 Detection Using a Highly-Sensitive Molecularly-Imprinted Electrochemical Sensor Based on an Electropolymerized Metal Organic Framework

Abstract

A sensitive electrochemical molecularly-imprinted sensor was developed for the detection of aflatoxin B1 (AFB1), by electropolymerization of p-aminothiophenol-functionalized gold nanoparticles in the presence of AFB1 as a template molecule. The extraction of the template leads to the formation of cavities that are able to specifically recognize and bind AFB1 through π-π interactions between AFB1 molecules and aniline moities. The performance of the developed sensor for the detection of AFB1 was investigated by linear sweep voltammetry using a hexacyanoferrate/hexacyanoferrite solution as a redox probe, the electron transfer rate increasing when the concentration of AFB1 increases, due to a p-doping effect. The molecularly-imprinted sensor exhibits a broad linear range, between 3.2 fM and 3.2 µM, and a quantification limit of 3 fM. Compared to the non-imprinted sensor, the imprinting factor was found to be 10. Selectivity studies were also performed towards the binding of other aflatoxins and ochratoxin A, proving good selectivity.

Molecularly Imprinted Polymers and Surface Imprinted Polymers Based Electrochemical Biosensor for Infectious Diseases

“…π-π interaction was used to recognize toxic protein aflatoxin B1 by the p-aminothiophenol-based MIPs. The sensitivity of the imprinted sensor was 11 times greater than that of the non-imprinted sensor by applying the π-donor/π-acceptor interaction [23]. Sensors 2020, 20, x FOR PEER REVIEW 4 of 14…”

Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

“…The template was then extracted from the polymer matrix, resulting in selective recognition sites for the analyte of interest. Several template molecules have been investigated such as estradiol [37], aflatoxin B1 [38], 1,3,5-trinitrotoluene [39], gemcitabine [40], glyphosate [41] and tetracycline [42]. These studies followed several steps for the fabrication of selective recognition cavities for the analytes of interest, which are summarized below: computational design, polymerization and removal of the template molecules.…”

“…Thus, in order to obtain thin polymeric films, cyclic voltammetry was employed. The electropolymerization was carried out in a solution of 10 mM [Fe(CN)6]−3/−4 in PBS (pH 7.2) containing 0.1 mg/mL p-aminothiophenol-functionalized AuNPs and 0.1 mg/mL template solution, by cycling the potential from −0.35 V to +0.80 V vs. SCE (Saturated Calomel Electrode), at a scan rate of 100 mV/s, for 10 cycles [27,[35][36][37][38]. In the case of estradiol, the electropolymerization was carried out from −0.35 to 0.60 V, in order to avoid the oxidation of estradiol which occurs at 0.60 V [35].…”

“…Compared to the MIP, the response currents of the NIP (Not Imprinted Polymer) did not change significantly with the concentration change, demonstrating the succesful formation of imprintig cavities in MIP films. The selectivity of the MIP sensors was also investigated towards the binding of structurally related compounds, proving excellent selectivity [37][38][39][40][41][42]. The observed sensitivities of detection can be classified as: 1,3,5-trinitrotoluene > estradiol > gemcitabine > aflatoxin B1 > tetracyclin > glyphosate; these different sensitivities are due to the different rates of doping, concerning the number of imprinted cavities and the charge transfer rate.…”

Molecularly imprinted polyaniline molecular receptor–based chemical sensor for the electrochemical determination of melamine

“…MIP films with superior performance were synthesized by combining the polymerization and immobilization steps using electropolymerization technique to prepare electrochemical sensors . Furthermore, combining the advantages of electrosynthesis and molecularly imprinted conducting polymers (MICPs) such as flexibility, low cost, light weight, stability, and simple preparation with that of electroanalytical methods like high speed, sensitivity, cheapness, and selectivity offers electrochemical sensors with the best sensitivity and selectivity towards the target analyte . Thus, MICP‐based electrochemical sensors are the most interesting electronic devices for the determination of food adulterants including MA.…”