A Flow-Injection Photoelectrochemical Sensor Based on TiO₂Nanotube Arrays for Organic Compound Detection

Abstract

A novel flow-injection photoelectrochemical sensor based on photocatalytic properties of TiO2 nanotube arrays (NATs) was achieved for organic compounds detection. The structure and morphology of TiO2 NTAs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Glucose was used as organic compound for photoelectrochemical detection test. The photocurrent response of TiO2 NTAs electrode to glucose was measured by cyclic voltammetry and chronoamperometry in dark and under illumination, respectively. Photoelectrochemical detection parameters, such as applied potential, optical power and pH value of electrolyte, were optimized to be 0.2 V, 36 mW/cm2 and pH value of 7. Photoelectrochemical detection of glucose under optimized conditions achieved sensitivity of 0.11 μA·μM−1 in concentration ranging from 10 to 1200 μM, the lowest detectable concentration of 10 μM and calculated detection limit (3σ) of 2.7 μM. The detection mechanism of this photoelectrochemical sensor was also discussed.