Negatively charged molybdate mediated nitrogen-doped graphene quantum dots as a fluorescence turn on probe for phosphate ion in aqueous media and living cells

Yuhong Wang; Weiyang Weng; Hu Xu; Yong Luo; Dan Guo; Dan Li; Dawei Li

doi:10.1016/j.aca.2019.07.023

Negatively charged molybdate mediated nitrogen-doped graphene quantum dots as a fluorescence turn on probe for phosphate ion in aqueous media and living cells

Anal Chim Acta. 2019 Nov 8:1080:196-205. doi: 10.1016/j.aca.2019.07.023. Epub 2019 Jul 12.

Authors

Yuhong Wang¹, Weiyang Weng¹, Hu Xu², Yong Luo³, Dan Guo⁴, Dan Li¹, Dawei Li⁵

Affiliations

¹ Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China.
² Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China. Electronic address: xuhu@sit.edu.cn.
³ State Key Laboratory of Polyolefins and Catalysis, Shanghai Key Laboratory of Catalysis Technology for Polyolefins (Shanghai Research Institute of Chemical Industry Co., Ltd., Shanghai), Shanghai, 200062, China.
⁴ Key Laboratory for Advanced Materials, East China University of Science and Technology, Shanghai, 200237, China.
⁵ Key Laboratory for Advanced Materials, East China University of Science and Technology, Shanghai, 200237, China. Electronic address: daweili@ecust.edu.cn.

PMID: 31409470
DOI: 10.1016/j.aca.2019.07.023

Abstract

Since inorganic phosphate ion (PO₄^3-) plays very important roles in environment or living organisms, developing a selective and sensitive detection method for PO₄^3- is highly desired. Owing to the superior optical properties, graphene quantum dots (GQDs) have been developed as a promising emitting material in fluorescence analysis. Herein, we reported the first example of negatively charged molybdate-mediated nitrogen doped graphene quantum dots (Mo₇O₂₄^6--mediated N-GQDs) as a fluorescence "off-on" probe for PO₄^3-via "anion ion-mediated" strategy. The N-GQDs was firstly modified with Mo₇O₂₄^6- through a complex bonding system containing ionic and hydrogen bonds. The formation of N-GQDs/Mo₇O₂₄^6- complex leaded to photoluminescence (PL) quenching of N-GQDs. In the presence of PO₄^3-, strong affinity between PO₄^3- and Mo₇O₂₄^6- produced ammonium phosphomolybdate, which destroyed the pre-formed N-GQDs/Mo₇O₂₄^6- structure and detached Mo₇O₂₄^6- from N-GQDs surface. Thus, the PL of N-GQDS was in turn switched on. Under optimal conditions, this probe exhibited a good linear relationship between PL response and PO₄^3- concentration in the range from 7.0 to 30.0 μM with a limit of detection of 50 nM. Also this probe with high selectivity and sensitivity has been successfully used to sense PO₄^3- in natural water, biological fluid, and living cells.

Keywords: Fluorescence turn on; Graphene quantum dots; Phosphate ion detection.

MeSH terms

Cell Line, Tumor
Fluorescent Dyes / chemistry*
Graphite / chemistry*
Humans
Hydrogen-Ion Concentration
Limit of Detection
Microscopy, Fluorescence / methods
Molybdenum / chemistry*
Nanocomposites / chemistry
Nitrogen / chemistry
Phosphates / blood*
Quantum Dots / chemistry*
Rivers / chemistry
Spectrometry, Fluorescence / methods
Water Pollutants, Chemical / analysis

Substances

Fluorescent Dyes
Phosphates
Water Pollutants, Chemical
molybdate
Graphite
Molybdenum
Nitrogen