Ultrasensitive detection of melamine based on a DNA-labeled immunosensor

作者：Yin H; Zhu Y; Xu L; Kuang H^*; Wang L; Xu C

来源：Biosensors and Bioelectronics, 2013, 42(1): 51-55.

DOI：10.1016/j.bios.2012.10.089

• DNA-labeled immunosensor
• Food safety
• Melamine detection

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 0.001-10pgg-1 was obtained with a limit of detection of 0.3fgg-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 1ppm. 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.