Phosphorene-gold nanocomposite based microfluidic aptasensor for the detection of okadaic acid

This study demonstrates the preparation and functioning of an electrochemical microfluidic biochip for the detection of OA. The screen printed carbon electrode (SPCE) was modified by phosphorene-gold nanocomposite onto which an aptamer specific to OA was immobilized. BP-Au nanocomposites were synthesized by in-situ, on-step method without the use of a reducing agent. Potassium ferro-ferri cyanide was used as a redox pair to quantify signal strength. To improve reaction time, increase sensitivity and portability, a microfluidic platform was designed and developed. This device comprised of channels identified for specific purposes such as sample mixing and incubation. Overall, the integrated system consisted of a polydimethylsiloxane microfluidic chip housing an aptamer modified SPCE, as a single detection module for Okadaic acid. The nanomaterials and the microfluidic channels prepared were spectroscopically and electrochemically analyzed. Differential pulse voltammograms revealed a detection limit of 8 pM, while a linear range was found between 10 nM–250 nM. Selectivity studies were also performed with spiked mussel samples and other interfering species. This point-of- care device can be deployed to perform on-farm assays in fishing units.Graphical abstract
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research