Development and characterization of a titanium dioxide-based semiconductor photoelectrochemical detector

Abstract

The development and characterization of a flow-through semiconductor-based titanium dioxide photoelectrochemical detector for flow in|ection analysis and liquid chromatography Is described. The detector Is nonselectlve, responding to a variety of organic analytes Including amines, aromatic alcohols, hydroquinones, aldehydes, and furans with redox potentials less positive than the valence band edge of the titanium dioxide semiconductor. An investigation of the Illuminated photoelectrochemistry and dark semiconductor electrochemical properties of the detector was carried out as a function of solvent system, electrochemical potential, and TIOj production variables. Illumination Intensity, titanium oxidation temperature, and electrode potential controlled the magnitude of the photoelectrochemical currents. Duration of thermal oxidation and the amount of hydrogen doping determined the ratio of the light to dark current for the analyte. Linearity over 2 orders of magnitude and detection limits In acetonitrile of 40 and 140 pmol, for p -aminoacetanllide and dlethylamlne, respectively, were demonstrated. Illumination of the semiconducting TI02 wire electrode along a cylindrical electrochemical cell Indicated the possible application of this spatially-resolved detection technique to whole column detection chromatography.

Progress in the studies of photoelectrochemical sensors

“…Compounds such as amines, aromatic alcohols, hydroquinones, aldehydes, and furans with redox potentials less positive than the valence band of TiO 2 could respond at the electrode. Compounds such as sugars, aliphatic ketones, and aliphatic esters, which were not easily oxidized by the photo holes of TiO 2 , could not be sensitively detected [61] .…”

“…Since then, the application of semiconductors in photoelectrochemical sensors started. Later on, based on the above reaction mechanism, Brown et al [61] detected a series of organic analytes. Compounds such as amines, aromatic alcohols, hydroquinones, aldehydes, and furans with redox potentials less positive than the valence band of TiO 2 could respond at the electrode.…”

Facile fabrication of an aptasensor for thrombin based on graphitic carbon nitride/TiO2 with high visible-light photoelectrochemical activity

“…Due to its high selectivity and sensitivity, short response time, minimal sample consumption and low background signals, photoelectrical sensor has become a powerful technology in many fields such as medical diagnostics, food safety, target detection, and environmental science (Brown et al, 1992;Freeman et al, 2013;Yue et al, 2013). Aptamers are oligonucleotides (DNA or RNA) artificially synthesized using an in vitro selection method named SELEX (Ellington and Szostak, 1990;Hermann and Patel, 2000).…”

An ultrasensitive label-free immunosensor based on CdS sensitized Fe–TiO2 with high visible-light photoelectrochemical activity

“…Photoelectrochemical (PEC) sensor based on photoelectric phenomenon has become a promising tool due to its desirable sensitivity, low background signals and good analytical performance (Brown et al, 1992;Li et al, 2012;Yan et al, 2014).…”