Sensing, detoxification and bactericidal applications of nitrogen-doped carbon dots

Abstract

Here, a one-pot hydrothermal synthesis technique was used to create nitrogen-doped carbon dots (N-CDs). Their structural and optical properties were assessed using XPS, XRD, Raman, UV–Vis, and fluorescence spectrophotometer. The N-CDs demonstrated encouraging emission quenching towards p-NP (p-Nitrophenol) and developed a sensing approach between 0.25 and 125 μM concentrations, from which a linear equation with a 20 nM detection limit was generated. In comparison to river and circulating water samples, the practicality demonstrated positive recovery rates together with impressive accuracy and precision. Additionally, the multi-functionality of N-CDs was investigated further in the catalytic reduction of methyl orange (MO) dye. With a good regression coefficient(0.9904) (R2) and rate constant (Kcat) (0.0208 min−1), N-CDs were able to reduce the azo groups in 8 min completely. Additionally, the bactericidal efficiency of N-CDs against gram-positive (Staphylococcus aureus, Listeria monocytogenes) and gram-negative (Escherichia coli, Salmonella enterica) bacteria was encouraging. The well-diffusion method demonstrated a good zone of inhibition, and the microdilution method demonstrated a promising minimum bactericidal concentration (MBC) of 470–940 μg/mL and minimum inhibitory concentration (MIC) of 240–470 μg/mL. The suggested fluorescent material may prove useful in the future for creating a fluorescence sensor, catalysts to combat water pollution, and antibacterial sprays to combat dangerous microorganisms.