Cobalt hexacyanoferrate electrodeposited on electrode with the assistance of laponite: The enhanced electrochemical sensing of captopril

Abstract In this work, Co 2+ ions were initially intercalated into the layers of laponite and then cobalt hexacyanoferrates (CoHCFe) were electrogenerated on the surface of laponite-Co 2+ modified ITO via square wave voltammetry (SWV). At scan rate of 10 mV s −1 , the electrochemical response of the ITO/laponite/CoHCFe showed two pairs of well-defined redox peaks located about 0.44 and 0.672 V vs.SCE, attributed to the redox reaction of Co II /Co III and Fe II /Fe III , respectively. The modified electrode was highly electrocatalytic to the captopril oxidation. Moreover, the ITO/laponite/CoHCFe exhibited an enhanced analytical performance for amperometric detection of captopril with two enlarged linear ranges from 3.0 × 10 −7 to 1.27 × 10 −4  M and 1.63 × 10 −4 to 3.76 × 10 −4  M and a low detection limit (0.29 μM). The modified electrode was used for electrocatalytic determination of captopril in some real samples.