Carbon dots derived from frankincense soot for ratiometric and colorimetric detection of lead (II)

Varsha Lisa John; Fasila P M; Chaithra K P; Vinod T P

doi:10.1088/1361-6528/ac8e76

Carbon dots derived from frankincense soot for ratiometric and colorimetric detection of lead (II)

Nanotechnology. 2022 Sep 20;33(49). doi: 10.1088/1361-6528/ac8e76.

Authors

Varsha Lisa John¹, Fasila P M², Chaithra K P¹, Vinod T P¹

Affiliations

¹ Department of Chemistry, CHRIST (Deemed to be University), Bangalore 560029, India.
² Department of Chemistry, Sir Syed College, Taliparamba, Kannur, Kerala 670142, India.

PMID: 36049475
DOI: 10.1088/1361-6528/ac8e76

Abstract

We report a simple one-pot hydrothermal synthesis of carbon dots from frankincense soot. Carbon dots prepared from frankincense (FI-CDs) have narrow size distribution with an average size of 1.80 nm. FI-CDs emit intense blue fluorescence without additional surface functionalization or modification. A negative surface charge was observed for FI-CDs, indicating the abundance of epoxy, carboxylic acid, and hydroxyl functionalities that accounts for their stability. A theoretical investigation of the FI-CDs attached to oxygen-rich functional groups is incorporated in this study. The characteristics of FI-CDs signify arm-chair orientation, which is confirmed by comparing the indirect bandgap of FI-CDs with the bandgap obtained from Tauc plots. Also, we demonstrate that the FI-CDs are promising fluoroprobes for the ratiometric detection of Pb²⁺ions (detection limit of 0.12μM). The addition of Pb²⁺to FI-CD solution quenched the fluorescence intensity, which is observable under illumination by UV light LED chips. We demonstrate a smartphone-assisted quantification of the fluorescence intensity change providing an efficient strategy for the colorimetric sensing of Pb²⁺in real-life samples.

Keywords: TD-DFT; UV light LED chip; carbon dots; detection of lead; frankincense soot; photoluminescence.