A reusable capacitive immunosensor for detection of Salmonella spp. based on grafted ethylene diamine and self-assembled gold nanoparticle monolayers

作者：Yang Gong Jun^*; Huang Jin Lin; Meng Wen Jing; Shen Ming; Jiao Xin An

来源：Analytica Chimica Acta, 2009, 647(2): 159-166.

DOI：10.1016/j.aca.2009.06.008

• Capacitive immunosensor
• Gold nanoparticles
• Electrochemical impedance spectroscopy
• Salmonella spp.
• Pork sample

Fabrication of a novel capacitive immunosensor based on grafted ethylene diamine and self-assembled gold nanoparticle monolayer on glassy Carbon electrode for the detection of Salmonella spp. is described for the first time. In the present study, the Salmonella spp. monoclonal antibodies (denoted as McAbs) was immobilized on gold nanoparticles. Interaction of McAbs and Salmonella spp. was detected directly using the electrochemical impedance spectroscopy (EIS) technique. The experimental results showed that the concentration of antigen was measured through the relative change in capacitance in the corresponding specific binding of Salmonella spp. and McAbs. Under the optimized conditions, the relative changes in capacitance were proportional to the logarithmic values of Salmonella spp. concentrations in the range of 1.0 X 10(2) to 1.0 x 10(5) CFU mL(-1) (r=0.991) with the detection limit of 1.0 x 10(2) CFU mL(-1). The stability of proposed immunosensor could be estimated by determining the relative change in capacitance, which remained almost the same in two months and decreased gradually to 85.3% of initial value after four months' storage. The used immunosensor could be regenerated repeatedly by immersing in glycine-HCl buffer solution (pH 2.8). Finally, the proposed immunosensor was successfully used for the detection of Salmonella spp. in lab-processed commercial pork samples.

• 出版日期2009-8-11
• 单位扬州大学