An efficient chemiluminescent probe based on Ni-doped CsPbBr3 perovskite nanocrystals embedded in mesoporous SiO2 for sensitive assay of L–cysteine

Abstract

This study presents an efficient chemiluminescence (CL) probe based on perovskite nanocrystals (NCs) for detection of L–cysteine (L–Cys). It consists of nickel–doped CsPbBr3 NCs embedded in the mesoporous SiO2 matrix as CL reagent and cerium (IV) as an oxidant in aqueous environment. The probe was designed for the highly selective determination of L–Cys based on its remarkable enhancing effect on the CL intensity. The colloidal nanocomposite of nickel–doped CsPbBr3 NCs@SiO2 with photoluminescence quantum yield of 58% was fabricated by ligand–assisted re–precipitation method and characterized by using UV–Vis absorption, FT–IR, X–ray diffraction, and transmission electron microscopy. The sensor was utilized to determine L–Cys in the linear concentration range of 20–300 nM with a detection limit of 12.8 nM. Direct chemical oxidation of Ni–doped CsPbBr3 NCs@SiO2 by Ce(IV) was the single cause of the formation of the excited-state NCs and subsequent production of CL. The developed probe provides outstanding selectivity towards L–Cys over structurally related compounds. Accurate determination of L–Cys in human serum samples was achieved without interference, and the results were confirmed by HPLC method.