Electrochemical characterization of SnO 2 /rGO nanostructure for selective quantification of captopril in real matrix

Captopril (CAP) is one of the most broadly consumed anti-hypertension drug that caused various harmful effects such as zinc deficiency, cough, agranulocytosis, and angioedema. Thus, monitoring the low-level concentration of CAP through reliable and sensitive method is of great significance. The electrocatalytic properties of newly fabricated sensor based on SnO 2 /rGO/PtE was evaluated through Tafel plot and electrochemical impedance spectroscopy. The engineered sensor exhibited excellent response for CAP under optimal conditions e.g., PBS electrolyte (pH 5), scan sweep 90 mV/s and potential window (0.6 to 1.9 V). For effectiveness of developed sensor, two low and high concentration ranges of CAP were optimized as 1 to 700 nM and 10 100 µM, respectively. The LOD’s of SnO 2 /rGO/PtE for CAP for low and high concentrations were calculated as 0.061 nM and 0.0018 µM. Moreover, the exceptional long-term stability and anti-interference profile of SnO 2 /rGO/PtE suggested the reliability of chemically modified sensor. Graphical Abstract