氧化锌纳米棒光电极对核黄素的光致电化学响应及应用

Photoelectrochemical Response and Application of ZnO Nanorods Photoelectrode to Riboflavin

基于核黄素在第二工作电极上的预还原,将还原型核黄素作为电子给体纳入氧化锌纳米棒光电极的光致电化学反应过程,构建了一种新的光致电化学反应系统.优化了电化学制备氧化锌纳米棒光电极的方法,研究了核黄素与氧化锌纳米棒光电极的光致电化学反应机理,建立了一种测定核黄素的光致电化学分析法.在p H=6.5的缓冲溶液中,以玻碳电极为预还原电极,在峰值波长为365 nm、能量为450μW/cm^2的光照下,在偏压0.1 V处测得的光电流与1.00×10^(-5)~1.00μmol/L核黄素浓度的对数值成正比,检出限为6.0×10^(-7)μmol/L(S/N=3),灵敏度为195.6 n A/lg[c(μmol/L)].对实际样品测定的相对标准偏差小于6.25%,回收率为99.0%~104%,常见生化物质对核黄素光电流的响应无干扰.

In this work,based on the pre-reduction of riboflavin（RF） on the second working electrode,a new photoelectrochemical（PEC） system was fabricated by the reduced RF as an electron donor incorporated into PEC reaction process of zinc oxide nanorods photoelectrode（ZnONRP）. After optimizing the electro-chemical preparation for ZnONRP and studying the reaction mechanism of RF with ZnONRP,a PEC method for the determination of RF was developed. Under the optimized conditions of p H = 6. 5,- 0. 40 V as prereduction potential,illumination at 365 nm and light energy of 450 μW/cm2,the photocurrent at bias voltage0. 1 V is proportional to the logarithm of RF concentration in the range of 1. 00×10^-5—1. 00 μmol/L with sensitivity of 195. 6 n A/lg[c（μmol/L） ],and the detection limit was estimated to be 6. 00×10^-7μmol/L（S/N =3）. Determination results for real samples showed that the relative standard deviation is less than 6. 25% and the recovery rate is 99. 0%—104%. Compared with other methods for the determination of RF,the proposed method has various advantages,such as wide measurement range,high sensitivity,simple equipment and convenient operation. And common biochemical substances were not interfering with the photocurrent response of RF.