A novel label-free electrochemical immunosensor for carcinoembryonic antigen detection based on the [Ag-Ag2O]/SiO2 nanocomposite material as a redox probe

作者：Yuan Yali; Yuan Ruo^*; Chai Yaqin; Zhuo Ying; Mao Li; Yuan Shirong

来源：Journal of Electroanalytical Chemistry, 2010, 643(1-2): 15-19.

DOI：10.1016/j.jelechem.2010.03.014

• Immunosensor
• Redox probe
• [Ag-Ag2O]/SiO2 nanocomposite material
• Gold nanoparticle (nano-Au)
• Carcinoembryonic antigen (CEA)

In this work, a new [Ag-Ag2O]/SiO2 nanocomposite material was prepared using 3-aminopropyltrimethoxysilane (AMPTS) as a connected material to absorb Ag-Ag2O nanoparticles on SiO2 surface. The [Ag-Ag2O]/SiO2 nanocomposite material had large surface, excellent conductivity and well redox activity. Then, a label-free immunosensor was prepared by the employment of the novel [Ag-Ag2O]/SiO2 nanocomposite material for determination of carcinoembryonic antigen (CEA). And the fabrication process of immunosensor was investigated by scanning electron microscopy (SEM) and cyclic voltammetry (CV). The [Ag-Ag2O]/SiO2 nanocomposite material could not only construct a desirable nano-sized surface with large surface-to-volume ratio to immobilize anti-CEA with the cooperation of nano-Au but also act as redox probe for the determination of CEA. By optimization of assay conditions on the pH of HAc-NaAc buffer, temperature and incubation time, the proposed electrode was proven to be sensitive and specific to detect CEA in the range of 0.5 to 160 ng/mL with a detection limit of 0.14 ng/mL, which was well within the normal physiological range. Additionally, the capability of the proposed immunosensor for direct CEA quantification in human blood serum was also discussed here.

• 出版日期2010-5-1
• 单位西南大学