Fig. 5. (a) The SWV curves of the aptasensor obtained for different concentrations of cocaine in 0.02 M PBS, pH 5.5, and (b) the corresponding calibration graph of SWV response versus cocaine concentration. Inset shows the calibration graph in the concentration range of 0.05–1.00 μM (c) the selectivity of electrochemical aptasensor incubated with 10 μM cocaine in the absence and presence of 100 μM caffeine, heroine and morphine–codeine mixture.
