Ziaeddin Jafari - Department of Chemical Engineering, Yasouj University, Yasouj, Iran
Abdolrasoul Pouranfard - Department of Chemical Engineering, Yasouj University, Yasouj, Iran
Negin Rahimi - Tehran University of Medical Sciences, Tehran, Iran

An extremely sensitive and selective electrochemical sensor based on anatase TiO۲ nanosheet hierarchical spheres (TiO۲NSHSs), Pt nanoparticles (PtNPs), carbon paste electrode (CPE) and ۲,۳-dihydro-۲-(۳,۴-dihydroxyphenyl) quinazolin-۴(۱H)-one (DHP) for determination of isoprenaline (IP) in the presence of phenobarbital (PB) was developed. The excellent synergistic effect of TiO۲NSHSs, PtNPs and DHP showed significantly enhanced electrocatalytic activity for IP and PB. In order to characterize the developed nanosensor, the scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS) and voltammetry were used. Electrochemical behavior of the DHP/PtNPs/TiO۲NSHSs/CPE sensor studied using differential pulse voltammetry (DPV), cyclic voltammetry (CV) and EIS. Several effective parameters were investigated and optimized on the nanosensor response. The proposed sensor, under the optimized conditions, showed two linear dynamic ranges from ۰.۰۵- ۲۰.۰ µM and ۲۰.۰-۹۰۰.۰ µM with a low detection limit of ۷.۰ nmol.L −۱ for IP determination. Finally, the modified sensor was employed to determine the analytes in human blood plasma with ±۰.۳% error. Validation of the proposed method was performed using high-performance liquid chromatography (HPLC).

TiO۲ nanosheet hierarchical spheres, Electrocatalytic properties, Electrochemical impedance spectroscopy, Phenobarbital