A "turn off-on" fluorescent sensor for detection of Cr(Ⅵ) based on upconversion nanoparticles and nanoporphyrin

Jiaying Zeng; Ting Zhang; Geyu Liang; Jingwen Mo; Jianxiong Zhu; Longhui Qin; Xiaojun Liu; Zhonghua Ni

doi:10.1016/j.saa.2024.124002

A "turn off-on" fluorescent sensor for detection of Cr(Ⅵ) based on upconversion nanoparticles and nanoporphyrin

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Apr 15:311:124002. doi: 10.1016/j.saa.2024.124002. Epub 2024 Feb 8.

Authors

Jiaying Zeng¹, Ting Zhang¹, Geyu Liang¹, Jingwen Mo², Jianxiong Zhu³, Longhui Qin³, Xiaojun Liu⁴, Zhonghua Ni⁵

Affiliations

¹ School of Public Health, Southeast University, Nanjing 210009, PR China.
² Engineering Research Center of New Light Sources Technology & Equipment-Ministry of Education, Jiangsu Key Laboratory for Design & Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096, PR China. Electronic address: jwmo@seu.edu.cn.
³ Engineering Research Center of New Light Sources Technology & Equipment-Ministry of Education, Jiangsu Key Laboratory for Design & Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096, PR China.
⁴ Engineering Research Center of New Light Sources Technology & Equipment-Ministry of Education, Jiangsu Key Laboratory for Design & Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096, PR China. Electronic address: liuxiaojun@seu.edu.cn.
⁵ Engineering Research Center of New Light Sources Technology & Equipment-Ministry of Education, Jiangsu Key Laboratory for Design & Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096, PR China. Electronic address: nzh2003@seu.edu.cn.

PMID: 38364512
DOI: 10.1016/j.saa.2024.124002

Abstract

Hexavalent chromium (Cr(Ⅵ)) is a significant environmental pollutant because of its toxic and carcinogenic properties and wide use in various industries. Hence, there is an urgent need to develop accurate and selective approaches to detect the concentration of Cr(Ⅵ) in agricultural and aquaculture products to help humans avoid potential hazards of indirectly taking in Cr(Ⅵ). In this work, we report a "turn off-on" fluorescent sensor based on citric acid coated, 808 nm-excited core-shell upconversion nanoparticles (CA-UCNPs) and self-assembled copper porphyrin nanoparticles (nano CuTPyP) for sensitive and specific detection of Cr(Ⅵ). Nano copper 5, 10, 15, 20-tetra(4-pyridyl)-21H-23H- porphine obtained by acid-base neutralization micelle-confined self-assembly method function as an effective quencher due to its excellent optical property and water solubility. Through electrostatic interactions, positively charged nano CuTPyP are attracted to the surface of negatively charged CA-UCNPs, which can almost completely quench the fluorescence emission. In the presence of Cr(Ⅵ), nano CuTPyP can discriminatively interact with Cr(Ⅵ) and form nano CuTPyP/Cr(Ⅵ) complex, which separates nano CuTPyP from CA-UCNPs and restores the fluorescence. The sensing system exhibits a good linear response to Cr(Ⅵ) concentration in the range from 0.5 to 400 µM with a detection limit of 0.36 µM. The sensing method also displays high selectivity against other common ions including trivalent chromium and is applied to the analysis of Cr(Ⅵ) in actual rice and fish samples with satisfactory results.

Keywords: Chromium; Fluorescence; Nanoporphyrin; Turn off–on; Upconversion nanoparticles.