Gold nanoparticles coated zinc oxide nanorods as the matrix for enhanced L-lactate sensing.

In this study, an enzymatic electrochemical biosensor for L-lactate detection was proposed. The device was developed based on gold nanoparticles (Au NPs) modified zinc oxide nanorods (ZnO NRs). The sensing performance of the device was examined by cyclic voltammetry and amperometry. Compared with pristine ZnO based biosensor, Au/ZnO based sensor exhibited higher sensitivity of 24.56 μA cm(-2) mM(-1), smaller K(M)(app) of 1.58 mM, lower detection limit of 6 μM and wider linear range of 10 μM-0.6 mM for L-lactate detection. The introduction of Au NPs enhances electro-catalytic ability and electron migration, which contributes to the improvement of the sensing performance. Hence, the results confirm the essential character of Au NPs in such semiconductor based electrochemical biosensing system.