基于钴离子介导信号转换的抗坏血酸比色分析

Colorimetric Detection of Ascorbic Acid Based on Co^2+-mediated Signal Transformation

抗坏血酸是许多生化过程所必需的一种生物小分子。借助于羟基氧化钴纳米片的氧化性和钴离子与硫氰酸根离子之间强的螯合作用,本文报道了一种基于钴离子介导信号转换的新方法用于抗坏血酸的比色分析。在抗坏血酸存在时,羟基氧化钴纳米片被还原降解产生二价钴离子,钴离子与硫氰酸根离子之间通过螯合作用生成蓝色的阴离子络合物[Co(NCS)4]^2-,在625nm处产生可见吸收信号。在优化条件下,体系625nm处的吸收值与抗坏血酸浓度在0.03~0.45 mmol/L范围内呈良好的线性关系,线性方程为A625=0.638c(mmol/L)+0.042,相关系数R=0.993,检测限(3S/N)为1.5μmol/L。

Ascorbic acid(AA)is a significant small biomolecule involved in many biochemical processes.Profiting from the oxidizability of cobalt oxyhydroxide nanoflakes(CNFs)and strong chelating interactions between Co^2+ and SCN^-,a novel colorimetric assay of AA was reported based on the Co^2+-mediated signal transformation.In the presence of AA,CNFs were reduced into Co^2+,then strongly chelated with SCN^- to form a stable blueish anion complex([Co(NCS)4]^2-),resulting in a visible absorption signal at 625 nm.Under the optimal conditions,the maximum absorbance was linear with AA concentration from 0.03 to 0.45 mmol/L.The regression equation is A625 nm=0.638c(mmol/L)+0.042 with a correlation coefficient of 0.993 and a limit of detection of 1.5μmol/L(3 S/N).