Nanobiocomposite Modified Carbon-Ceramic Electrode Based on Nano-TiO2-Plant Tissue and Its Application for Electrocatalytic Oxidation of Dopamine

A new modified carbon-ceramic electrode was prepared by incorporating TiO2 nanoparticle into sol-gel network by accompanying apple tissue. A mixture of fine graphite powder with 15 wt% of TiO2 nanoparticle was used for the preparation of the carbon matrix and finally modification with a known amount weighted of apple tissue. The apple tissue containing polyphenol oxidase enzyme acts as molecular recognition element. The electrocatalytic oxidation of dopamine was investigated on the surface of the nanobiocomposite modified carbon-ceramic electrode using cyclic voltammetry, chronoamperometry and amperometry techniques. Effect of pH, scan rate, TiO2 percentage on the response of modified electrode was studied. The prepared modified electrode presented a linear range for dopamine from 5.0×10−6 to 1.2×10−3 M in buffered solutions with pH 7.4 by amperometry. The detection limit was 3.41×10−6 M dopamine. The response of the modified carbon-ceramic electrode and unmodified carbon-ceramic electrode was compared.