Synthesis, characterization and electrochemical analysis of TiO2 nanostructures for sensing L-Cysteine and hydrogen peroxide

L-Cyteine is a form of amino acid found in human body. Retaining the exact quantity of L-Cyteine is important for better functioning of the body. A novel hybrid TiO2 nanostructure (H-TNTs) was prepared on both sides of Ti sheet using the first-step anodization in used (residual) ethylene glycol (EG) based electrolyte. The H-TNTs was explored as an enzyme-free electrochemical biosensor for the detection of L-Cysteine (L-Cyst) and hydrogen peroxide (H2O2). Structural analysis revealed that annealed H-TNTs was anatase with uniform tube morphology and narrow pore size distribution of the top thin nanopomus layer. Electrochemical measurements demonstrated excellent electrocatalytic activities of H-TNTs with sensitivity and rapid response of L-Cyst (0.9914 mu A mM(-1) cm(-2), <2 s) and H2O2 (85.3 mu A mM(-1) cm(-2)' < 5 s) respectively. The DFT analysis described that TNT has greater affinity towards L-Cyst and H2O2 with stronger binding distances after the adsorption. The higher negative E(ads )values suggesting the stable and chemisorptions nature of the H-TNTs. The density of states (DOS) results show that E-gap of TNT was significantly reduced after both molecules adsorption. The fabricated electrochemical biosensor exhibited decent stability, excellent reproducibility, and good resistance to interfering molecules showing great potential, as a unique, non-enzymatic electrochemical sensor for future medical applications.