用于亚硝酸盐高灵敏检测的阴极型光电化学生物传感器

Nitrite, a common toxic inorganic contaminant, can cause a series of serious health issues once it entered into drinking water and food chain. It is considerably difficult to determine nitrite because of its unstable property. This topic will focus on the fabrication of the cathodic photoelectrochemical biosensor and its application to the rapid, selective, and sensitive determination of nitrite. First，copper-based ternary semiconductor (p-type) with excellent photoelectric property and photoelectrocatalytic activity will be synthesized as photocathode. And then, the biorecognition element with high affinity for nitrite will be immobilized on the photocathode. The catalytic reduction of captured nitrite on the photocathode will result in the variation of cathodic photocurrent. Finally, the nitrite will be successfully determined via collecting the cathodic photocurrent signal. The catalytic reduction process of captured nitrite and the mechanism of nitrite determination based on the proposed photoelectrochemical biosensor will be investigated. The photoelectrochemical biosensor with the fastest response speed, the best selectivity, and the highest sensitivity will be chosen to be applied to the determination of nitrite in real samples. The project will be expected to provide basic data to develop portable field devices for the determination of nitrite, as well as expand the detection range of photoelectrochemical biosensor to the selective determination of ions.

亚硝酸盐是一种普遍存在的、有毒的无机污染物，当它进入饮用水和食物链时，会引起一系列严重的人类健康风险。亚硝酸盐极易转化的性质为它的检测带来了相当大的难度。本项目提出构建阴极型光电化学生物传感器，用于快速、选择性和高灵敏检测亚硝酸盐。首先，合成具有良好光电响应和催化性能的三元铜基p-型半导体材料作为传感器的光阴极，然后将与亚硝酸盐具有高亲和力的生物识别元件固定在光阴极上，构建传感器。将亚硝酸盐的浓度变化与阴极光电流变化相关联，通过收集阴极光电流信号，实现亚硝酸盐的检测。研究亚硝酸盐被生物识别元件捕获后，在光阴极上被催化还原的行为，探究检测机理，选择响应速度最快、选择性最好、灵敏度最高的传感器应用于亚硝酸盐实际样品的检测。项目的完成有望为开发利用可再生能源的便携式现场检测亚硝酸盐设备，提供实验依据；并为拓宽光电化学生物传感器的应用范围，实现光电化学生物传感器对离子的选择性检测，开辟一条新的道路

集光学检测和电化学检测的优点于一身的光电化学传感器具有背景信号弱、灵敏度高、成本低、响应迅速，易于实现微型化的优点，在环境监测、食品安全、医疗健康等领域极具应用前景，是当前的研究热点之一。但目前光电化学传感器受其核心功能元件光活性物质的性质的影响，仍存在可见光利用率不高，电子转移速率较低，光生电荷复合率较高等问题亟待解决。在本项目研究中，我们成功合成了三元p-型半导体氧化物和三元复合材料替代二元过渡金属氧化物作为光活性物质，着重研究了新型光活性物质的结构设计、合成方法、及光电化学催化特性，结合生物识别元件构建了光电化学生物传感器，探讨了生物识别元件浓度、光活性物质用量、电解液等因素对传感器光电化学响应的影响，评价其实际应用性，实现了对目标污染物的自供能、高灵敏、选择性的检测，为新型光电化学生物传感器的构建与应用提供了新思路和策略。