Aggregation-induced enhanced photoluminescence in magnetic graphene oxide quantum dots as a fluorescence probe for As(iii) sensing

Pathan, Shabnam and Jalal, Misna and Prasad, Sanjay and Bose, Suryasarathi (2019) Aggregation-induced enhanced photoluminescence in magnetic graphene oxide quantum dots as a fluorescence probe for As(iii) sensing. In: JOURNAL OF MATERIALS CHEMISTRY A, 7 (14). pp. 8510-8520.

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Abstract

Clean drinking water is a basic need of human beings around the world. In the past few decades, many research groups have been trying different methods to exploit quantum dots (QDs) to decontaminate water but, due to either cost or cumbersome steps, they have been unsuccessful. We have tried exploiting graphene quantum dots (GQDs) for heavy metal ion detection, particularly for arsenic ions in contaminated water. Herein, we prepared highly sensitive and selective magnetic GQD (Fe-GQDs) based sensors for the turn on sensing of As3+ ions. Systematic characterization of the prepared magnetic GQDs was done using different spectroscopic techniques. Impressively, Fe-GQDs exhibited good selectivity for As3+ ions over a wide pH range. This turn on sensing of As3+ ions can be explained by the fact that Fe-GQDs aggregates were formed upon the addition of As3+ ions, which restricted the intra-molecular vibrational motion and consequently made the entire system emissive. A combination of techniques, such as time-correlated single-photon counting (TCSPC) experiments, Raman spectroscopy, XPS, DLS and zeta potential analysis, was employed to understand the aggregation-induced enhanced emission (AIEE) mechanism. The resultant limit of detection (LOD) value for as-prepared fluorescent Fe-GQDs was 5.1 ppb, which is well below the permissible limit for arsenic in drinking water. A reactive oxygen species (ROS) study in the presence and absence of UV light revealed the potential of the proposed quantum dots to act as an antibacterial agent. Overall, the low LOD value, the selectivity of Fe-GQDs over a wide pH range and the ROS study render our work of practical significance.

Item Type:	Journal Article
Publication:	JOURNAL OF MATERIALS CHEMISTRY A
Publisher:	ROYAL SOC CHEMISTRY
Additional Information:	The copyright for this article belongs to Royal Society of Chemistry
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	11 May 2019 06:45
Last Modified:	11 May 2019 06:45
URI:	http://eprints.iisc.ac.in/id/eprint/62538

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