Synthesis of water-soluble fluorescent carbon nanoparticles (CNPs) from nanosecond pulsed laser ablation in ethanol

• Published in: Optics and laser technology Vol. 135; p. 106717
• Main Authors: Yogesh, Gaurav Kumar, Shuaib, E.P., Kalai Priya, A., Rohini, P., Anandhan, Sathyan Vivekanand, Krishnan, Uma Maheswari, Kalyanavalli, V., Shukla, Shivam, Sastikumar, D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.03.2021; Elsevier BV
• Subjects: Ablation; Acetone; Cardiomyocytes; Cell-imaging; Charcoal; CNPs; Emission analysis; Ethanol; Fluorescence; High resolution electron microscopy; Image analysis; Image transmission; Isopropanol; Laser Ablation; Lasers; Medical imaging; Nanoparticles; Particle size distribution; Photoluminescence; Pulsed lasers; Room temperature; Visible spectrum; Water chemistry; Laser Ablation; Fluorescence; CNPs; Cardiomyocytes; Cell-imaging; Charcoal
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2020.106717

[Display omitted] •CNPs directly obtained by ns-PLA in ethanol are incompatible for cell imaging.•Post ns-PLA approach is a facile method to achieve water soluble CNPs.•Water soluble CNPs exhibits similar fluorescence as CNPs in ethanol.•In vitro studies reveals the biocompatibility of water soluble CNPs in human cardiomyocytes. Traditionally, CNPs directly obtained from nanosecond pulsed laser ablation (ns-PLA) in an organic solvent like ethanol, isopropyl alcohol and acetone, possess toxic characteristics with excellent fluorescent properties. However, water-soluble CNPs are found to be non-toxic with weak fluorescent properties. In this study, a post-ablation method was utilized to achieve water-soluble fluorescent CNPs. Initially, the colloidal Eth-CNPs solution was obtained from ns-PLA of charcoal powder in the ethanol, which was subsequently dried at room temperature and then dispersed in water to achieve the final water-soluble CNPs (W-CNPs). The High-resolution Transmission Electron Microscopy (HRTEM) image analysis of W-CNPs shows quasi-spherical size particle distribution with an average particle size found to be around 21 nm. XPS studies of charcoal powder and W-CNPs confirm the creation of fluorescent emissive defects state on the surface of W-CNPs under laser ablation in ethanol. Photoluminescence studies of W-CNPs demonstrated the wavelength-dependent PL emission, with peak PL emission in the blue region of the visible spectrum. In vitro studies indicated the non-toxic nature of the W-CNPs at low and high concentration (1, 5 and 10% v/v) in human cardiomyocytes. Herein, the W-CNPs obtained from post-ns-PLA was found to exhibit both blue and green fluorescence in the cardiomyocytes and hence, it can be exploited as a fluoro probe in bioimaging applications.