Highly sensitive and selective detection of dimethylamine through Nb-doping of TiO2 nanotubes for potential use in seafood quality control

Dimethylamine is an important indicator to check the degradation and control the quality of seafood. In this work, we present a novel, simple, fast and inexpensive method to detect dimethylamine in the range of 5-50 ppm that might be potentially useful to control the seafood quality in the future. The developed gas sensor is based on niobium-doped titanium dioxide nanotubes. The tubular structures were successfully synthesized using anodic oxidation method. The sensing properties of the obtained materials were studied towards dimethylamine gas for the first time. Dimethylamine behaves like an electron donor and induces an increase in conductivity of the n-type titanium dioxide. The presence of niobium in the titanium dioxide structure plays a crucial role to improve the functional properties of the material. Niobium acts as a donor promoting the process of gas adsorption on the structure. The response of Nb doped-material towards 10 ppm of dimethylamine is higher more than an order of magnitude compared to the pristine titanium dioxide nanotubes, leading to an essential improvement in their gas sensing performance. The obtained results enable the development of a dimethylamine gas sensor device based on titanium dioxide for the real-time monitoring and freshness detection of seafood products.