Highly sensitive and label free on-site monitoring immunosensor for detection of Aflatoxin B1 from real samples

• Published in: Analytical biochemistry 2024-06, Vol.689, p.115493-115493, Article 115493
• Main Authors: Baruah, Susmita, Mohanta, D., Betty, C.A.
• Format: Article
• Language: English
• Subjects: AuNPs; Composite electrode; Conducting polymer; Differential pulse voltammetry; Electrochemical sensing; Transient capacitance
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2024.115493

Aflatoxin B1 (AF-B1) are toxins secreted by secondary metabolites of molds that have adverse effects on humans and animals resulting in huge economic losses. Here we report on field useable, cost effective and direct electrochemical sensor based on conducting polymer composite electrode, Poly (3,4-ethylenedioxythiophene): polystyrene sulphonic acid (PEDOT-PSS) for label-free detection of AF-B1. Structural and morphological characterization of composite electrodes were carried out using XRD and SEM. We compared two different electroanalytical techniques namely, transient capacitance and differential pulse voltammetry, to select the most prominent technique for analyzing the mycotoxin easily. For direct detection of AF-B1, transient capacitance measurement at 77 and 1000 Hz was employed wherein sensor showed linearity in 18.18–300.0 ng mL−1 range at 77 Hz for AF-B1. Best limit of detection (LOD) for AF-B1 was 55.41 ng mL−1 (369 pM) at 77 Hz with very good repeatability. DPV showed linearity in the range 18.18–342.85 ng mL−1 with LOD 435 pM. For demonstration of application of this sensor directly using minimum sample preparation, AF-B1 sensing has been confirmed successfully using white button mushrooms and okra stored at ambient conditions. Sensor response with real samples suggest usefulness of sensor to monitor stored farm products easily. [Display omitted] •Comparable sensors performance for Aflatoxin B1 with two methods namely, transient capacitance and DPV.•Selective, Au/GO/PEDOT-PSS capacitive sensor with LOD of 55.41 ng mL−1 (369 pM) at 77 Hz and 62.45 ng mL−1 (416 pM) at 1 kHz.•Selective, Au/GO/PEDOT-PSS amperometric sensor with LOD of ∼65 ng/mL (435 pM) within range 18.18–342.85 ng/mL•Satisfactory sensor performance with real samples, white button mushrooms and okra.