Electrochemical Aptasensor Based on Poly(Neutral Red) and Carboxylated Pillar[5]arene for Sensitive Determination of Aflatoxin M1

Abstract

Aptasensor for highly sensitive determination of aflatoxin M1 (AFM1) was developed on the base of glassy carbon electrode (GCE) covered with polymeric Neutral red (NR) dye obtained by electropolymerization in the presence of polycarboxylated pillar[5]arene derivative. Aptamer against AFM1 and NR label were then covalently linked to the carboxylic groups of the carrier by carbodiimide binding. At presence of AFM1 the cathodic peak current related to the NR conversion decreases. AFM1 induced also an increase of the charge transfer resistance measured by electrochemical impedance spectroscopy. In optimal conditions, this make it possible to determine from 5 to 120 ng/L AFM1 in standard solutions with limit of detection (LOD) of 0.5 ng/L. The aptasensor was validated on the spiked samples of cow and sheep milk as well as in kefir after their methanol dilution. Reliable detection of the 40–160 ng/kg of mycotoxins was reached. This is below limited threshold value (50 μg/kg) established in EC.

Label-Free Impedance Sensing of Aflatoxin B1 with Polyaniline Nanofibers/Au Nanoparticle Electrode Array

“…Microfluidic cell embedded interdigitated electrodes were utilized for the detection of bacteria in food samples [ 10 ], printed carbon electrodes were coated with Concanavalin A for bacteria detection in water [ 11 ]. Also MoS 2 nanosheets on Indium tin oxide (ITO) electrodes [ 12 ], aptamers on carbon electrode [ 13 ], and aptamers on glassy carbon electrodes [ 14 ] were demonstrated for the detection of various types of mycotoxins based on the changes in R ct . In this sense, EIS based techniques combined with different nanostructures of the receptive surfaces have been applied in the development of AFB 1 detection.…”

Electrochemical Aptasensor with Layer‐by‐layer Deposited Polyaniline for Aflatoxin M1 Voltammetric Determination

“…However, both EIS and voltammetric approaches are sensitive to non‐specific adsorption of the interferences and require special measures for suppressing undesired interactions with naked electrode surface or charged layers assembled. Similar drawbacks were reported for non‐Faradaic EIS where changes in the redox status or conductivity of the sensing layer are assessed with no diffusionally free redox probes .…”

“…Contrary to the previous results obtained with 60 min. incubation [25], the PANI peak currents decreased with the AFM1 concentration starting from the first minimal concentration of the analyte ( Figure 7A). Increasing AFM1 concentration increased the peak potential difference indicating slower electron transfer in the inner PANI layer.…”

Nanoparticles based on the zwitterionic pillar[5]arene and Ag+: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

“…The ability of macrocyclic systems to form supramolecular associates, due to noncovalent interactions with Ag + , can reduce toxicity and preserve the biomedical properties of the resulting nanoscale particles that do not contain Ag-Ag bonds [14]. However, the main problem is the fact that macrocyclic hosts have low solubility in water, which significantly narrows their application [15][16][17][18][19][20]. Therefore, we propose to use water-soluble derivatives of decasubstituted pillar [5]arenes containing sulfobetaine fragments in their structure as target structures.…”