Simple and Rapid Detection of Melamine in Milk Based on T-Melamine-T Duplex Structure and SYBR Green Ⅰ / 分析化学

ABSTRACT

A novel fluorescence homogeneous biosensing strategy was developed for simple, rapid and sensitive detection of melamine in milk by using the polythymine oligonucleotide T24 and SYBR Green Ⅰ. In the absence of melamine, the fluorescence of SYBR Green Ⅰ was weak. The interactions between the single strand oligonucleotide T24 and SYBR Green Ⅰ were weak. In contrast, the presence of melamine drove the formation of T-melamine-T folded structure and enabled the SYBR Green Ⅰ to intercalate into double-strand DNA, resulting in the enhancement of fluorescence intensity. The results revealed that the method allowed a sensitive, simple, and rapid assay of melamine with a linear response range from 0. 1 μmol/L to 10 μmol/L and a detection limit of 35 nmol/L.