基于有机薄膜晶体管的新型光电化学传感技术及沙门氏菌检测应用研究

The rapid detection of pathogenic bacterium like Salmonella with high sensitivity and high specificity is of great significance to the prevention and control of foodborne diseases. On the other hand, the two types of biosensors based on organic electrochemical transistor (OECT) and photoelectrochemical (PEC) techniques have many complementary advantages and are supposed to be integrated together to achieve highly sensitive bioanalysis. Thus, this project proposes a novel biosensor based on organic photoelectrochemical transistor (OPECT) and uses it for highly sensitive detection of Salmonella.. In this project, the signal transduction mechanisms of OPECT-based biosensors will be well studied through the implementation of excellent gate electrodes with photoelectrical functional interfaces. The detection of Salmonella with high sensitivity, low detection limit, and high specificity will also be investigated using OPECT biosensors with different sensing mechanisms. Moreover, the miniaturized OPECT arrays are also proposed for the rapid and high-throughput detection of Salmonella. The new universal sensing technique is supposed to be used for other bioanalyses such as the detection of virus, which will play an important role in the areas of control of foodborne diseases and protection of public health.

对沙门氏菌等致病性细菌的快速、高灵敏、高特异性检测对预防和控制食源性疾病具有重要意义。由于有机电化学晶体管（OECT）与光电化学（PEC）两种传感技术在生物检测中都具有高灵敏等特性且很多技术优势互补，因此本项目拟将OECT和PEC两种技术结合一起，开发一种基于有机光电化学晶体管（OPECT）的新型、具有更高灵敏度的生物传感技术，并对沙门氏菌的高灵敏检测展开系统研究。. 通过构建高效栅电极光电功能传感界面，揭示新型OPECT生物传感的信号传导机制；通过设计不同的检测原理来实现OPECT对沙门氏菌的高灵敏、低检测极限、高特异性检测，并阐述其传感新机制；同时通过研究微米级小型化及阵列式OPECT器件，实现对沙门氏菌的微量、快速、高通量检测。本项目的传感技术具有普适性，可拓展到病毒检测等诸多领域，并具有潜在应用价值，有望在控制食源性疾病、保护公共卫生和人民群众身体健康等方面发挥重要作用。

致病性细菌是食源性疾病的主要诱因及罪魁祸首，而沙门氏菌是一类常见的致病菌，能够通过多种感染渠道导致沙门氏菌感染疫情大规模爆发，近年来其耐药性的出现也引起全世界范围内的广泛担忧。因此，对沙门氏菌的准确检测对预防和控制沙门氏菌疾病具有非常重要的意义。. 本项目构建了基于有机光电化学晶体管（OPECT）的新型传感技术，并研究了OPECT在沙门氏菌传感中的应用。结果表明，基于位阻效应的OPECT沙门氏菌传感器对沙门氏菌的检测极限为100cells/mL，其传感原理主要是基于沙门氏菌对栅电极表面电荷转移的阻碍作用。此外，通过Au NPs标记沙门氏菌，引入CdS QDs与Au NPs间的EPI效应，沙门氏菌传感器的检测极限可达10cells/mL，相对于单纯基于位阻效应的沙门氏菌传感器检测结果降低了一个数量级。与此同时，设计了微小型OPECT器件并应用于传感研究。利用微加工技术制备了微米级OPECT器件，并对其尺寸结构及电学性能等进行了优化。同时，初步研究了微米级OPECT器件在细菌传感中的应用。结果表明，利用微米级OPECT器件可以实现对细菌的微量检测。我们相信，OPECT传感技术具有非常高的普适性，可拓展到病毒、海洋微生物、细胞检测等诸多领域的研究，具有较好的可持续科学研究价值。