Fig. 3

a Potential/V vs.SCE. The CV of Au/GCE in 0.1 M PBS (pH 7.0) solution containing 1.0 mM UA without (1) and with (3) visible light illumination; visible light illumination starts from the spot where the arrow is pointing (2). Scan rate 50 mV s⁻¹. b Time/s. Photocurrent response of Au/GCE under visible light illumination in 0.1 M PBS (pH 7.0) solution containing 1.0 mM UA at 0.48 V. The illumination from a Xe lamp was interrupted every 30 s