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.