Synthesis of TiO₂-Au nanoparticles as sensors of 3-mercaptopropionic acid

3-Mercaptopropionic acid (3MPA) is an essential organic compound in aquatic environments given that has a fundamental role in the biogeochemistry of sulfur (S), is generated during the degradation of amino acids containing S, such as methionine in some plants and sequential demethylation of dimethylsulfoniopropionate (DMSP). The level of concentration of the 3MPA in aquatic environments is from nanomolar to micromolar. Also, 3MPA is toxic at certain concentrations and is used in experimentation to cause seizures in mice for scientific advances on epilepsy. Therefore, in this work, we report the developed of a novel portable, selective, and fast response sensor; based on an Au-TiO2 electrode for the quantification of 3MPA. The electrochemical technique of cyclic voltammetry was used to obtain the calibration curve of the sensor, with a limit of detection (LOD) of 50 nM in a linear range of 0 to 80 μM.

Keywords: 3-mercaptopropionic acid, detection, gold nanoparticles, titanium dioxide.