Acid Oxidation of Muskmelon Fruit for the Fabrication of Carbon Dots with Specific Emission Colors for Recognition of Hg2+ Ions and Cell Imaging

Mittal L Desai; Sanjay Jha; Hirakendu Basu; Rakesh Kumar Singhal; Tae-Jung Park; Suresh Kumar Kailasa

doi:10.1021/acsomega.9b02730

Acid Oxidation of Muskmelon Fruit for the Fabrication of Carbon Dots with Specific Emission Colors for Recognition of Hg²⁺ Ions and Cell Imaging

ACS Omega. 2019 Nov 4;4(21):19332-19340. doi: 10.1021/acsomega.9b02730. eCollection 2019 Nov 19.

Authors

Mittal L Desai¹, Sanjay Jha², Hirakendu Basu³, Rakesh Kumar Singhal³, Tae-Jung Park⁴, Suresh Kumar Kailasa¹

Affiliations

¹ Department of Applied Chemistry, S. V. National Institute of Technology, Surat 395 007, India.
² Gujarat Agricultural Biotechnology Institute, Navsari Agricultural University, Surat 395007, India.
³ Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085, India.
⁴ Department of Chemistry, Institute of Interdisciplinary Convergence Research, Research Institute of Halal Industrialization Technology, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.

Abstract

In this study, water-soluble emissive carbon dots (CDs) are effectively fabricated with specific optical properties and colors by acid oxidation of muskmelon (Cucumis melo) fruit, which are termed as C. melo CDs (CMCDs). The fluorescence properties of CMCDs were tuned by controlling the experimental conditions that allow them to emit different colors, that is, blue (B-), green (G-), and yellow (Y-) CMCDs, with different emission wavelengths at 432, 515, and 554 nm when excited at 342, 415, and 425 nm, respectively. The fabricated multicolor-emissive CDs were confirmed by various analytical techniques. The sizes of B-, G-, and Y-CMCDs were found to be ∼3.5, ∼4.3, and ∼5.8 nm, respectively. The as-prepared CMCDs display stable emissions with quantum yields of 7.07, 26.9, and 14.3% for the three CMCDs, which could act as a promising probe for the selective detection of Hg²⁺ ions. Upon the addition of Hg²⁺ ions, the fluorescence intensity of G-CMCDs at 515 nm was quenched largely than that of B- and Y-CMCDs. The spectroscopic results display that the G-CMCDs acted as a sensor for the detection of Hg²⁺ ions with a wide linear range from 1.0 to 25 μM (R ² = 0.9855) with a detection limit of 0.33 μM. This method was successfully applied to detect Hg²⁺ ions in biological and water samples. The fabricated multicolor-emissive CMCDs possess the cell (Cunninghamella elegans, Aspergillus flavus, and Rhizoctonia solani) imaging property, suggesting the biocompatible nature for multicolor imaging of various cells.