A novel sensor based on nanobiocomposite Au--In 2 O 3 --chitosan modified acetylene black paste electrode for sensitive detection of antimycotic ciclopirox olamine.

For the first time, a sensitive conductive nanobiocomposite sensor consisting of Au-In2 O3 nanocomposite and chitosan (CS) was successfully prepared and used for the modification of acetylene black paste electrode (Au--In2 O3 --CS/ABPE). The phase structures, composition and morphology of Au-In2 O3 nanocomposite were characterized by X-ray diffraction (XRD), energy-dispersed X-ray (EDX) and transmission electron microscopy (TEM). Electrochemical activities and surface analysis of the biosensor electrode Au--In2 O3 --CS/ABPE were investigated using scanning electron microscopy (SEM), cyclic voltammetry and square wave voltammetry. The modified electrode showed an excellent electrochemical activity toward the electro-oxidation of the antimycotic ciclopirox olamine (CPX) leading to a significant improvement in sensitivity as compared to the bare ABPE. The proposed biosensor demonstrated linearity in the range 0.199 - 16.22µmolL-1 , with high sensitivity (64.57μAµmolL-1 cm-2 ) and detection limit of 6.64 × 10-9 molL-1 CPX. The analytical performance of this biosensor was evaluated for detection of CPX in pharmaceutical formulations with good accuracy and precision. This proposed method was validated by UPLC and the results are in agreement at the 95% confidence level.