CaF2 nanoparticles as peroxidase mimics for rapid and sensitive detection of aldosterone.

Abstract

In this work, CaF2 nanoparticles were successfully synthesized by a simple direct precipitation method and firstly used as a peroxidase mimics for rapid and high sensitive colorimetric detection of aldosterone. The CaF2 nanoparticles were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). The CaF2 nanoparticles can oxidize 3,3 ,5,5 -tetramethylbenzidine (TMB) to produce a blue product oxidized TMB (oxTMB) in the presence of H2O2 and this peroxidase-like activity of CaF2 is found out to follow Michaelis-Menten kinetics. Experiments showed that the catalytic mechanism of CaF2 nanoparticles was attributed to that it could result in the decomposition of H2O2 to produce hydroxyl radicals (•OH). The absorbance change value of the reaction system was linear with the aldosterone concentration in the range of 2.0-40.0\u202fnM, and the detection limit was 0.6\u202fnM. Moreover, the developed method was applied to detect aldosterone in human serum samples. It provides a new platform for enzyme functional simulation and analytical sensing research.