Synthesis of green fluorescent carbon quantum dots using waste polyolefins residue for Cu2+ ion sensing and live cell imaging

•A highly green fluorescent carbon dots was synthesized from waste plastic residue.•The synthesized non toxic carbon dots were employed for the detection of the Cu2+ ions and live cell imaging.•Limit of detection (LOD) of Cu2+ ions is 6.33 nM.•The Cu2+ ions are also used for cell imaging of triple negative breast cancer cells (MDA-MB 468 cells) and real water samples.

The residue obtained from the pyrolysis of waste polyolefins, has been used for preparation of highly green-visual fluorescent carbon quantum dots (CQDs) by a simple one step hydrothermal approach consisting of ultrasonic-assisted chemical oxidation. These CQDs were characterized by UV-vis absorption spectroscopy, fluorescence spectroscopy, TEM, XRD, and FTIR. The CQDs possessed high stability in aqueous solution and exhibited strong fluorescence with quantum yield of 4.84%. The use of these CQDs as a fluorescent sensor for Cu2+ ions detection has been explored. The synthesized CQDs have excellent selectivity and sensitivity towards Cu2+ ions with a limit of detection (LOD) 6.33 nM and linear detection range of 1-8.0 μM. These CQDs have also shown their utility for analysis of real water samples and have the potential to use for triple negative breast cancer cells (MDA-MB 468 cells) imaging.