Environmentally benign, bright luminescent carbon dots from IV bag waste and chitosan for antimicrobial and bioimaging applications

Luminescent carbon dots have gained significant attention in various fields due to their unique optical properties and potential applications. Here, the study was aimed to propose a novel and sustainable approach for the synthesis of luminescent carbon dots (ICDs) using IV (Intravenous) medical bag waste. The ICDs were synthesized through a facile and cost-effective method that involved the carbonization of IV bag waste followed by surface functionalization with chitosan. The synthesized ICDs were characterized using UV-Visible spectrum (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The size of the ICDs is between 2 and 8 nm. The ICDs effectively inhibited the growth of both gram positive and gram negative bacterial strains with the inhibitory activity in the range of 11-14 mm and 12-18 mm, respectively. Results of antibiofilm activity of ICDs varying concentrations (50 and 100 μg/ml) showed that it effectively distorted the biofilm architecture and thereby validated its promising potentials. In vitro antioxidant activity showed remarkable DPPH radical scavenging potentials of ICDs (33.4%-70.1%). Results of MTT assay revealted that ICDs showed potent cytotoxic effect on HeLa cells in a dose dependant matter (25-400 μg/ml). Furthermore, when HeLa cells were excited at wavelengths of 380 nm, 440 nm and 540 nm, cell-imaging experiments using ICDs revealed the presence of blue, green, and red fluorescence. This innovative method not only addresses the issue of IV bag waste in a sustainable manner but also opens up exciting possibilities for the advancement of versatile carbon-based materials in the field of biomedicine.