Inorganic Salt Incorporated Solvothermal Synthesis of Multicolor Carbon Dots, Emission Mechanism, and Antibacterial Study

Abstract

Enriching the synthetic routes of functionalized carbon dots (C dots) and expanding their application are necessary for promoting research into carbon-based nanomaterials. In this study, we develop a one-step and efficient method to prepare excitation-dependent multicolor emissive carbon dots (M-C dots) with quaternary ammonium functional groups via a solvothermal reaction of chloroform, diethylamine, and ammonium carbonate. Through detailed structural characterizations and further reactions of surface functional groups (such as reduction, oxidation, and hydrolysis) on M-C dots, the excitation-dependent tunable photoluminescence behaviors are proposed to come from the multiple emission domains on the surface. The prepared M-C dots possess antibacterial activity against Gram-positive bacteria and Gram-negative bacteria. And the antibacterial effects of M-C dots were investigated by destroying the bacterial cell walls/membranes via strongly electrostatic interactions between positively charged M-C dots and negatively charged bacteria. This study provides a novel strategy to prepare functionalized C dots and reveals the nature of intrinsic multicolor emission of C dots.

Carbon Nanodots in Photodynamic Antimicrobial Therapy: A Review

“…These effects are discussed in a review by Anand et al [ 31 ] and have been mentioned by others [ 61 , 62 , 63 , 64 , 65 , 66 ]; they include cell well disruption [ 61 , 62 , 63 , 64 ] and DNA/RNA damage [ 61 , 65 , 66 ] to name a few. Nonetheless, studies demonstrate significant bactericidal capabilities from photosensitization using carbon dots; strains studied by the reports summarized herein are compiled in Figure 4 d, including multi-drug resistant (MDR) E. coli for one study and methicillin-resistant Staphylococcus aureus (MRSA) as well [ 19 ].…”

Synthesis of Multicolor Carbon Dots Based on Solvent Control and Its Application in the Detection of Crystal Violet

“…Moreover, the Raman spectra of the two peaks at 1363 and 1551 cm −1 correspond to the disordered structures or defects (D band) and the graphitic carbon domains (G band) (Figure S3). The intensity ratios of I D /I G are 1.14 and 1.04 for R-CDs and Y-CDs, respectively, indicating that R-CDs are more disordered and amorphous than Y-CDs [32,33].…”

Carbon Dots: An Emerging Smart Material for Analytical Applications

“…The synthesized CDs with increased nitrogen content resulted in high quantum yield of ~4% and led to the introduction of new functional groups like cyano. However, because of the carbon dot’s multicolour emissive property, these CDs have also opened up various applications for sensing and antibacterial activity [ 34 ]. The N-doped CDs developed by using Lantana camara berries via a simple green approach exhibited good quantum yield (QY) of 33.15%, high stability, high biocompatibility.…”