Electrochemical Strip Sensor Based on a Silver Nanoparticle-Embedded Conducting Polymer for Sensitive In Vitro Detection of an Antiviral Drug

A straightforwardand disposable electrochemical sensor was developedby the direct electrodeposition of silver nanoparticles (AgNPs) ona conducting polymer and an acid-functionalized carbon nanotube-modifiedscreen-printed carbon electrode (f-CNT/SPCE) for the detection ofthe antiviral drug valganciclovir (VGC). A scaffold layer of the conductingpolymer 2,6-diaminopyridine (p-DAP) was electrodeposited on an f-CNT/SPCEsurface via a potentiodynamic polarization method. Later, homogeneousdeposition of AgNPs was carried out on the polymer-modified scaffoldlayers. The electrode activities related to the concentration of the polymersubstrate and the AgNP precursor were systematically optimized. Theelectrochemical oxidation of VGC by SPCE/f-CNT/p-DAP-AgNPs was investigatedby square-wave voltammetry. The modified sensor exhibited an attractiveelectroanalytical performance toward VGC with high sensitivity (nanomolarrange), selectivity (in the presence of uric acid and dopamine), reproducibility,and long-term storage stability. Potential real-world applicationsof the modified screen-printed sensor were demonstrated using artificialurine/serum and industrial water samples. The straightforward designand attractive analytical performance of the conductive polymer-embeddedAgNP -modified screen-printed sensor suggest considerable promisefor use of this sensor in the point-of-care screening of antiviraldrugs. The sensor strip would also be useful in the screening of antiviraldrugs in industrial (quality control) and environmental (industryeffluents) applications.