Ultrasensitive detection of melamine based on a DNA-labeled immunosensor.

Honghong Yin, Yinyue Zhu, Liguang Xu, Hua Kuang, Libing Wang, Chuanlai Xu

School of Food Science & Technology, State Key Laboratory of Food Science & Technology, Jiangnan University, Wuxi 214122, China.

Biosensors & bioelectronics 2013 Apr 15

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A DNA-labeled immunosensor for melamine (MEL) detection is presented which combined the exponential amplification and quantitative effect of Real-Time quantitative PCR (RT-qPCR) with the simplicity and specificity of competitive antigen-antibody reaction. An excellent linear relationship between cycle threshold (Ct) and MEL concentration in the range of 0.001-10 pg g⁻¹ was obtained with a limit of detection of 0.3 fg g⁻¹. Compared with other methods, the sensitivity of this DNA-labeled immunosensor showed a 1000-fold improvement, and was below the strictest safety limit of 1 ppm. Furthermore, the specificity was excellent and the recovery in liquid milk samples spiked with MEL was satisfactory. With the advantages of high sensitivity and a low limit of detection (LOD), this sensor is a powerful and promising tool for the detection of other small molecules besides MEL. Copyright © 2012 Elsevier B.V. All rights reserved.

Citation

Honghong Yin, Yinyue Zhu, Liguang Xu, Hua Kuang, Libing Wang, Chuanlai Xu. Ultrasensitive detection of melamine based on a DNA-labeled immunosensor. Biosensors & bioelectronics. 2013 Apr 15;42:51-5