CdS|TiO<sub>2</sub> Non-Enzymatic Sulfide Photoelectrochemical Sensor
Cecilia I. Vázquez, Felipe Montero Bruni, Ana M. Baruzzi, Rodrigo A. Iglesias
Abstract
A non-enzymatic photoelectrochemical detection of aqueous sulfide and ascorbic acid, using an CdS <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert $ </tex-math></inline-formula> TiO2 nanotubes photoanode, is presented. Its performance is compared with a CdS <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert $ </tex-math></inline-formula> Pt photoanode. Both the electrodes show high sensitivity in the visible range with capabilities of detection at micromolar levels for sulfide and ascorbic acid. Photoelectrodes are also able to detect micromolar levels of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}\text{O}_{{2}}$ </tex-math></inline-formula> , but this analyte causes the degradation of CdS during photocurrent measurements, with the consequent release of Cd <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{{2}+}$ </tex-math></inline-formula> ions to the analyte solution.