Improved Sensing of Capsaicin with TiO2 Nanoparticles Modified Epoxy Graphite Electrode

The presented research focuses on the electrochemical determination of capsaicin, a lipophilic alkaloid which originates hotness in chili peppers. An electrochemical sensor based on epoxy-graphite composite with the modification of titanium dioxide (TiO2) nanoparticles is developed for the determination of this alkaloid. The measurements were carried out in glycine buffer at pH 2.5 using cyclic voltammetry. Two linear concentration ranges were obtained from 6 to 75 mu M (R=0.99) and from 12 to 138 mu M, with a detection limit of 5.34 mu M and 11.3 mu M capsaicin, for 1(st) and 2(nd) oxidation peak, respectively. The main advantage of developed sensor is its repeatability and robustness against fouling; the relative standard deviation (RSD) value was 2.53 % (n=10). This voltammetric sensing procedure has successfully been applied to quantify capsaicin in various real samples such as hot chili sauce and pharmaceutical preparations.