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

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.