A low cost universal photoelectrochemical detector for organic compounds based on photoelectrocatalytic oxidation at a nanostructured TiO 2 photoanode

Abstract

A photoelectrochemical detector (PECD) was developed for determination of organic compounds in flow injection analysis (FIA) and high performance liquid chromatography (HPLC) based on the extraordinary oxidation power of nanostructured TiO 2 photoanodes under UV illumination. The PECD is a simple, small, and compact photoelectrochemical cell consisting of low cost components such as a TiO 2 nanostructured photoanode and a UV-LED. Compared with conventional FIA and HPLC selective detectors, such as UV–Vis detector, electrochemical detector and fluorescent detector, the PECD has the advantage of being low cost, non-selective and sensitive. Using the FIA mode, the analytical principle of the PECD was demonstrated by detecting a large variety of organic compounds, such as sugars, amino acids, alcohol, straight chain carboxylic acids, and aromatic carboxylic acid. The PECD was subsequently coupled with a typical FIA and HPLC system for the determination of sugars. For the application in FIA, under the optimum experimental conditions, the linear ranges for glucose and sucrose were 25–600 μM and 25–500 μM, respectively, with the same detection limit of 10 μM. When the PECD was coupled with a HPLC system, the linear range for both glucose and sucrose was 7.5–200 mM with the same detection limit of 1 mM under the optimal experimental conditions.