Ultrasensitive photoelectrochemical immunoassay of indole-3-acetic acid based on the MPA modified CdS/RGO nanocomposites decorated ITO electrode

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• 作者：Bing Sun ; Lijian Chen ; Yan Xu ; Min Liu ; Huanshun Yin ; Shiyun Ai
• 关键词：Cadmium sulfides ; Reduced graphene oxide ; 3-Mercaptopropionic acid ; Photoelectrochemical immunosensor ; Indole-3-acetic acid
• 刊名：Biosensors and Bioelectronics
• 出版年：2014
• 出版时间：15 January, 2014
• 年：2014
• 卷：51
• 期：Complete
• 页码：164-169
• 全文大小：969 K

文摘

A novel ultrasensitive photoelectrochemical immunosensor was fabricated based on 3-mercaptopropionic acid stabilized CdS/reduced graphene oxide (MPA-CdS/RGO) nanocomposites for indole-3-acetic acid (IAA) detection. The MPA-CdS/RGO nanocomposites were synthesized by in situ solvothermal growth of triangulated pyramidal CdS nanoparticles on the RGO sheet. 3-Mercaptopropionic acid (MPA) was employed as the modifier and bridge to immobilize the antibody. The nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and UV/vis spectra. The results showed that the MPA-CdS/RGO nanocomposites revealed enhanced photocurrent response due to excellent electron transport properties of RGO and the improved assembly of CdS nanoparticles onto RGO sheet with the introduction of MPA. Based on the dependence of the photocurrent decline on the concentration of IAA, the proposed photoelectrochemical immunosensor for IAA depicted a linear range from 0.1 to 1000 ng/mL with a lower detection limit (0.05 ng/mL). The high sensitivity, reproducibility and specificity of the method permitted the method suitable to be used in real samples.