The passivation layers of an in situ-synthesized cadmium sulfide (CdS) nanowire (NW) photosensor were prepared for two reasons: (1) to improve the physical stability of the NW on an interdigitated electrode and (2) to enhance the immobilization efficiency of proteins for the on-chip immunoassay. The passivation layer was estimated to have suitable optical properties, and the photoresponse of photosensor was increased after the formation of passivation layer. The immobilization efficiency of a parylene-H film through covalent bonding was compared with the immobilization of Z-domains through physical adsorption. Finally, on-chip chemiluminescent immunoassay of bacteria was carried out by immobilizing antibodies against Escherichia coli through Z-domains for the orientation control of antibodies. The limit of detection was determined to be less than 10⁴E. coli/mL (n=3), and the sensitivity of bacterial detection was estimated to be 0.339 pA/E. coli/mL (n=3) with a linearity factor (R²) of 0.999. These results showed that the on-chip chemiluminescent immunoassay for bacterial detection could be performed using passivation layer coated CdS NW photosensor.

制备原位合成硫化镉（CdS）纳米线（NW）光电传感器的钝化层的原因有两个：（1）提高NW在指状电极上的物理稳定性；（2）增强NW在电极上的固定效率。蛋白用于片上免疫测定。估计钝化层具有合适的光学性质，并且在形成钝化层之后增加了光传感器的光响应。通过共价键合将聚对二甲苯-H薄膜的固定效率与通过物理吸附固定Z-结构域的固定效率进行了比较。最后，通过固定针对大肠杆菌的抗体进行细菌的芯片化学发光免疫测定通过Z结构域控制抗体的方向。确定的检出限小于10 ⁴ E. coli / mL（n = 3），细菌检测的灵敏度估计为0.339 pA / E. coli / mL（n = 3），具有线性因子（R ²）为0.999。这些结果表明，使用钝化层涂覆的CdS NW光传感器可以进行用于细菌检测的芯片化学发光免疫测定。