A Simple, Highly Sensitive, and Label-Free Impedimetric Immunosensor for Detection of Microcystin-LR in Water

Abstract

A simple, highly sensitive, and label-free impedimetric immunosensor for detection of microcystin-LR (MC-LR) has been developed by immobilizing anti-microcystin-LR on gold nanoparticle/L-cysteine coated electrode. Under optimal conditions, MC-LR could be determined with a detection limit of 1.82 × 10⁻² ng mL⁻¹ and a linearity between 0.05 and 300.0 ng mL⁻¹. Moreover, the immunosensor exhibited long-term stability, and good reproducibility of the signal could be obtained up to 42 times with an R.S.D. of 3.58%. The average recovery rate was in the range of 96.8 ∼ 112.5%. In addition, the whole detection time was only 15 min.

Keywords:

• Impedimetric immunosensor
• Microcystin–LR
• Water

Acknowledgments

The authors thank Professor JianTang, Ms. Gu Xiaohong, Ms. Gong Yan, Mr. Zhao Chuncheng, and Mr. Ji Jian for their technical advice and assistance. We also appreciate the Suwei Research Ltd. of Microbiology of Jiangsu Province and Determination Center of Jiangnan University for supplying the research instruments, and Dr. Li Zaijun for the assistance in preparing the manuscript. This research was supported by the 863 (2007AA10Z428) National and providence funding (20806033, 2008017 and SKLF-KF-200905).