Ternary nanocomposites of Au/CuS/TiO2 for an ultrasensitive photoelectrochemical non-enzymatic glucose sensor

Abstract

A novel and highly sensitive photoelectrochemical biosensor for the detection of glucose based on ternary nanocomposites of Au/CuS/TiO₂ (Au/CuS/TiO₂) has been fabricated. Highly ordered TiO₂ nanotube arrays (TiO₂ NTs) were prepared by anodization of Ti foils, and CuS nanoparticles (NPs) and Au NPs were deposited on TiO₂ NTs by the successive ionic layer adsorption and reaction (SILAR) method. The resultant Au/CuS/TiO₂ exhibited excellent photoelectrochemical behavior as a glucose sensor under white light illumination due to the remarkable photocatalytic capabilities of TiO₂ and CuS, and the surface plasmonic resonance (SPR) effect of Au NPs. The fabricated Au/CuS/TiO₂ non-enzymatic photoelectrochemical sensor showed brilliant catalytic activity, favourable selectivity, good reproducibility and long-term stability for glucose detection under optimized conditions. The linear range was 0.1–3 μM (R = 0.9942) with a detection limit of 0.03 μM (S/N = 3). Moreover, the proposed sensor detected glucose in human serum samples. Thus, Au/CuS/TiO₂ appears to be a promising photocatalyst for a non-enzymatic glucose sensor.