Coumarin-Modified Graphene Quantum Dots as a Sensing Platform for Multicomponent Detection and Its Applications in Fruits and Living Cells

Zhaochuan Yu; Wenhui Ma; Tao Wu; Jing Wen; Yong Zhang; Liyan Wang; Yuqian He; Hongtao Chu; Minggang Hu

doi:10.1021/acsomega.9b04387

Coumarin-Modified Graphene Quantum Dots as a Sensing Platform for Multicomponent Detection and Its Applications in Fruits and Living Cells

ACS Omega. 2020 Mar 25;5(13):7369-7378. doi: 10.1021/acsomega.9b04387. eCollection 2020 Apr 7.

Authors

Zhaochuan Yu¹, Wenhui Ma¹, Tao Wu¹, Jing Wen¹, Yong Zhang¹, Liyan Wang¹, Yuqian He¹, Hongtao Chu¹, Minggang Hu¹

Affiliation

¹ College of Chemistry and Chemical Engineering and College of Materials Science and Engineering, Qiqihar University, 42 Wenhua avenue, Qiqihar 161006, China.

Abstract

In this work, coumarin derivatives (C) are used to enhance the fluorescence of graphene quantum dots (GQDs) by covalently linking the carboxyl groups on the edge of the GQD sheet. The as-synthesized coumarin-modified graphene quantum dots (C-GQDs) have a uniform particle size with an average diameter of 3.6 nm. Simultaneously, the C-GQDs have strong fluorescence emission, excellent photostability, and high fluorescence quantum yield. C-GQDs and CN^- can form a C-GQDs+CN^- system due to deprotonation and/or intermolecular interactions. The introduced hydroquinone (HQ) is oxidized to benzoquinone (BQ), and the interaction between BQ and the C-GQDs+CN^- system could lead to fluorescence enhancement of C-GQDs. Meanwhile, the redox reaction between BQ and ascorbic acid (AA) can be used for quantitative detection of AA with CN^- and HQ being used as substrates. Based on the above mechanism, C-GQDs are developed as a multicomponent detection and sensing platform, and the detection limits for CN^-, HQ, and AA were 4.7, 2.2, and 2.2 nM, respectively. More importantly, satisfactory results were obtained when the platform was used to detect CN^-, HQ, and AA in living cells and fresh fruits.