The Role of a Semiconductor Chalcogenide in a Label-Free Aptasensor for Detection of Ultra-Trace amounts of Aflatoxin B1 in Wheat Flour

Addressed herein, Bismuth sulfide (Bi2S3) as a synthetic semiconductor chalcogenide applied in fabrication process of an aptasensor as a signal promoter for ultra-trace detection of aflatoxin B1(AFB1). The analytical signal was improved by using optimized amounts of Bi2S3 for electrode modification. The AFB1 Aptamer single strand type(SSDNA) was simply immobilized on the cross section of a pencil lead through polydopamine layers. A wide concentration range of trace amounts of AFB1(0.3-630nM) was supported by the fabricated aptasensor (pencil/polydopamine@Bi2S3/aptamer) using differential pulse voltammetry. Simple fabrication and no needing to electrode refreshment were part of the advantages of the suggested aptasensor. Finally, very low resulted detection limit(0.04nM) with a great sensitivity (0.076µA/nM) and also appropriate stability and repeatability led to application of the aptasensor in real sample analysis such as wheat flour with brilliant recovery percentages.