Poly(amidoamine) Dendrimer-Functionalized Magnetic Beads as an Immunosensing Probe for Electrochemical Immunoassay for Carbohydrate Antigen-125 in Human Serum

Abstract

The aim of this study is to develop a new potentiometric immunoassay for carbohydrate antigen-125 (CA125) in human serum by using poly(amidoamine) dendrimer-modified multifunctional magnetic beads conjugated with antibodies as immunosensing probes. With an external magnet, the developed immunosensor exhibited rapid potential response and wide linear range from 0.5 to 55 U/mL with a low detection limit of 0.1 U/mL CA125. The precision, selectivity, and stability of the developed immunosensor were acceptable. Analytical results obtained for the clinical serum specimen by the developed immunosensor were in accordance with those assayed by the enzyme-linked immunosorbent assay method.

Keywords:

• Carbohydrate antigen-125
• Electrochemical immunoassay
• Multifunctional magnetic beads
• Poly(amidoamine) dendrimer

Acknowledgments

This work is supported by Scientific Research Fund of Sichuan Provincial Education Department (grant no. 08zb001), and the Specialized Research Fund for the Excellent Young Teachers from Yibin University (grant no. 2005Z14), China.

Notes

^a LOD: the limit of detection.