Visible Illumination Enhanced Nonenzymatic Glucose Photobiosensor Based on TiO2 Nanorods Decorated With Au Nanoparticles.

A nonenzymatic glucose photobiosensor was developed based on Au-nanoparticle-decorated TiO2 nanorods (NRs) under visible illumination. Au nanoparticles (NPs) absorbed the visible illumination, resulting in surface plasmon resonance (SPR). The SPR of the Au NPs indicated that there was a strong electric field around them, which promoted the transport of more electrons to the TiO2 NRs and enhanced the glucose sensing properties. The sensing current under visible illumination was five times higher than in the dark when in 0.1 M NaOH solution at a potential of 0.17 V. Moreover, the Michaelis-Menten constant (Km) of the Au NPs/TiO2 NRs/FTO under visible illumination was 0.52 mM, which is much smaller than that reported previously. Moreover, these results indicate that the Au NPs/TiO2 NRs/FTO under visible illumination feature outstanding properties as a nonenzymatic glucose photobiosensor.

Nonenzymatic Glucose Sensor Based on Au/ZnO Core-Shell Nanostructures Decorated with Au Nanoparticles and Enhanced with Blue and Green Light.

Au/ZnO core-shell nanostructures decorated with Au nanoparticles were synthesized on an ITO/glass substrate. The investigated sensor contains 2-D, 1-D, and 0-D nanostructures to provide a large surface-area-to-volume ratio and catalytic quantum effect and to avoid the issues inherent in heterojunction interface barriers. The sensitivities of the fabricated glucose sensors in the dark and under blue and green LED illumination were 3371.9, 4410.9, and 4157.8 µA/cm2 mM-1, respectively. The achieved sensitivities are higher than previous reports on Au nanostructure sensors by 2-100 times. Further, the blue and green LED illumination respectively enhanced the sensitivity and CV glucose sensing currents by ∼30.8 and ∼23.3% and ∼27 and ∼35%. The detection limits of the glucose sensor in the dark and under visible illumination were the same at ∼0.5 µM. Moreover, these visible light illumination enhancements are attributed to the localized surface plasmon resonance effect.