为了利用可见光激发下半导体拉曼散射信号实现生物检测, 以窄带隙的MoS2材料构建了拉曼免疫标记探针, 用于实现对人IgG分子的高特异性识别。首先, 运用液相剥离法分别获得了MoS2和WS2微米材料, 以加热陈化处理分析了温度对532 nm激发下样品拉曼散射信号强度的影响。之后借助3-巯基丙酸修饰向MoS2材料表面引入羧基, 进而获得了可用于免疫检测的拉曼探针。最后, 以“抗体-待测物-抗体”的三层结构分析了基于MoS2拉曼散射的免疫检测性能。实验发现适当温度下加热陈化处理可增强过渡金属二硫化物的拉曼散射强度(70 ℃下最优)。多组对照实验结果表明, 免疫检测生物芯片的拉曼信号强度随人IgG浓度的升高而升高, 最终趋于饱和, 最低浓度的检测限达到1 fM, 实现了可见光激发下利用半导体拉曼散射信号对目标分子的高灵敏度、高特异性免疫检测。

To realize biodetection based on Raman scattering of semiconductor under visible light excitation, the Raman probe was constructed by using MoS2 material, a narrow bandgap semiconductor, to realize high specific recognition of the human IgG molecule. First, MoS2 and WS2 micromaterials were obtained by liquid-phase exfoliation method. The effect of temperature on the intensity of the Raman signal excitated by a 532 nm laser was analyzed through heating and aging treatment. Second, the carboxyl group was introduced to the surface of the MoS2 material by 3-mercaptopropionic acid modification, and a Raman probe was obtained. Finally, the performance of the MoS2 based immunoassay was evaluated by using a sandwich structure of "antibody-analyte-antibody". It was found that the heating and aging treatment at appropriate temperature enhanced the Raman scattering intensity of the transition metal disulfide (70 ℃ is the optimal). The results of control groups show that the Raman intensity of the immunodetection increased and saturated with the concentration of the human IgG. The detection limit is 1 fM. The current procedure realized immunoassays with high sensitivity and high specificity by using the Raman scattering of semiconductor under visible light excitation.