A Label-Free Fluorescent Sensor Based on Si,N-Codoped Carbon Quantum Dots with Enhanced Sensitivity for the Determination of Cr(VI)

Jinyu Zhang; Cai Jing; Binsong Wang

doi:10.3390/ma15051733

A Label-Free Fluorescent Sensor Based on Si,N-Codoped Carbon Quantum Dots with Enhanced Sensitivity for the Determination of Cr(VI)

Materials (Basel). 2022 Feb 25;15(5):1733. doi: 10.3390/ma15051733.

Authors

Jinyu Zhang¹, Cai Jing¹, Binsong Wang¹

Affiliation

¹ Key Laboratory of Functional Inorganic Material Chemistry, Department of Environmental Science, School of Chemistry and Materials Science, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, China.

Abstract

A signal shut-off probe of Si, N-codoped carbon quantum dots (Si, N-CQDs) was exploited to detect Cr(VI) by fluorescence quenching without the aid of any biomolecules or labeling materials. The sensing system prepared the precursor of diacetone acrylamide and the silane coupling agent 3-aminopropyltriethoxysilane (KH-550) by a simple hydrothermal method, and the quantum yield is as high as 75% Si, N-CQDs. The fluorescence stability and microstructure of the Si, N-CQDs were studied. The Si, N-CQDs has a high sensitivity for detecting Cr(VI) with the linear range of 0-200 μM and the detection limit of 0.995 μM. The quenching mechanism of Si, N-CQDs is attributed to FRET.

Keywords: Si,N-codoped carbon quantum dots; fluorescence sensor; hexavalent chromium; mechanism attributed to FRET.