Distinctive Solvatochromic Response of Fluorescent Carbon Dots Derived from Different Components of Aegle Marmelos Plant
Abstract
The phenomenal properties of carbon dots (CQDs) have provoked significant research interest in both theoretical and technological point of view. Herein a simple, inexpensive and eco-friendly approach was used for the fabrication of five different types of bright blue emitting CQDs from different fruit parts of Aegle Marmelos. The prepared particles possess average particle size of 5 to 10 nm and displayed higher quantum yield i.e. 62.1%, 40.1%, 41. 4%, 43.4% and 48.2% for CQD1, CQD2, CQD3, CQD4 and CQD5 respectively. The prepared CQDs also acquired exclusive characteristic features, comprising of high solubility, low toxicity as well as solvent polarity-dependent absorption and emission behaviour. The developed CQDs displayed higher stability over a period of four months. The detailed studies of CQDs in different solvents were further used to apprehend the solvatochromic behaviour of developed CQDs which have rarely been investigated. The provenience of solvatochromic shifts in various solvents and their corresponding effect on emission spectra of asynthesised CQDs were unveiled by scrutinizing the emission properties of five different types of formed CQDs as excitation wavelength. A red shift of 47 nm, 41 nm, 40 nm, 36 nm and 35 nm was observed in the emission spectra of CQD1 to CQD5 on moving towards the polar medium. The consequence of different solvents on the emission centers of CQDs were thoroughly investigated by calculating the solvent ET(30) polarity parameter for all chosen solvents. This work could unlock a new horizon to fabricate ratiometric probes of carbon dots for checking solvent polarity.
