Greenish‐Yellow Emitting Carbon Dots as 'On‐Off‐On' Fluorescent Probe for Selective Determination of Mercury (II) and Sulphide Ions. Issue 26 (11th July 2022)

• Record Type: Journal Article
• Authors: Naik, Vaibhav M.; Waghmare, Ravindra D.; Gore, Anil H.; Anbhule, Prashant V.; Kolekar, Govind B.
• Is Part Of: ChemistrySelect. Volume 7:Issue 26(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-11
• Subjects: carbon dots -- fluorescent sensor -- Hg2+ sensing -- S2− sensing -- static quenching; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.202201193
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Herein, we have reported a simple ratiometric yellow fluorescent probe based on carbon dots for selective determination of Hg 2+ and S 2− through a fluorescence 'ON‐OFF‐ON' strategy. The yellow emitting nitrogen doped carbon dots (Y‐NCD's) were synthesized by prolonged thermal carbonisation of p‐hydroxy benzoic acid and citric acid dissolved in ammonia solution at 180 °C. The purified Y‐NCD's shows excitation dependent emission with maximum intensity at 550 nm showing bright yellow fluorescence when excited at 480 nm. The linear response for detection of Hg 2+ ions ranges from 0 to 260 nM with a detection limit of 27.2 nM whereas the linear range for sulphide ions is from 0 to 1.1 μM with limit of detection 0.11 μM. The proposed sensor show excellent applicability for real sample analysis with satisfactory results. Abstract : Schematic representation of synthesis of greenish yellow emitting carbon dots (Y‐NCD's) by thermal carbonisation of p‐hydroxy benzoic acid and citric acid dissolved in ammonia solution at 180 °C. Initially, greenish‐yellow fluorescence of Y‐NCD's diminishes in presence of mercuric ions due to binding of Hg 2+ ions to the surface of Y‐NCD's. After addition of sulphide ions to Y‐NCD's‐Hg 2+ system, the fluorescence of Y‐NCD's recovers due to interaction between sulphide ions and Hg 2+ from the Y‐NCD's surface thus leaving Y‐NCD's in its free form.