基于钙黄绿素-臧红T荧光共振能量转移检测六偏磷酸钠
摘要
In a medium of tris-HCl buffer (pH 8.5), calcein (donor) can react with safranine T (acceptor) efficiently to produce fluorescence resonance energy transfer (FRET). However, the addition of sodium hexametaphosphate (SHMP) destroyed the FRET system because of the electrostatic interaction between SHMP and the acceptor, which makes fluorescence change ratio between the increased fluorescence intensity of calcein and the reduced fluorescence of ST (Δ<italic>F</italic><sub>D</sub>/Δ<italic>F</italic><sub>A</sub>) has a good linear correlated with the concentration of SHMP. Based on the phenomena, a novel rapid FRET method for determination of sodium hexametaphosphate was developed. Under the optimized conditions, the linear range is 3.0×10<sup>-</sup><sup>6</sup>-1.0×10<sup>-</sup><sup>5</sup> mol/L, and the relative standard deviation (RSD) is 3.1% for determination of sodium hexametaphosphat (<italic>c</italic>=6.0×10<sup>-</sup><sup>6</sup>, <italic>n</italic>=11). The proposed method is of high selectivity, simple to operate and rapid detection, and is successfully applied to determine the concentration of SHMP in drink samples.