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Updated: Oct 21, 2025

Light-Induced In Situ Transmission Electron Microscopy for Observation of the Liquid-Soft Matter Interaction
Published on: July 26, 2022
Photodynamic effect of light emitting diodes on E. coli and human skin cells induced by a graphene-based ternary
Maria Suciu1, Sebastian Porav2, Teodora Radu2
1National Institute for Research and Development of Isotopic and Molecular Technologies, Donat 67-103 Str., RO-400293 Cluj-Napoca, Romania; Biology and Geology Faculty, Babes-Bolyai University, 5-7 Clinicilor Str, Cluj-Napoca, Romania.
Abstract:
In this paper, the photodynamic effect of a ternary nanocomposite (TiO2-Ag/graphene) on Escherichia coli bacteria and two human cell lines: A375 (melanoma) and HaCaT (keratinocyte) after exposure to different wavelength domains (blue, green or red-Light Emitting Diode, LED) was analyzed. The results obtained through bioassays were correlated with the morphological, structural and spectral data obtained through FT-IR, XPS and UV-Vis spectroscopy, powder X-Ray diffractometry (XRD) and STEM/EDX techniques, leading to conclusions that showed different photodynamic activation mechanisms and effects on bacteria and human cells, depending on the wavelength. The nanocomposite proved a therapeutic potential for blue light-activated antibacterial treatment and revealed a keratinocyte cytotoxic effect under blue and green LEDs. The red light-nanocomposite duo gave a metabolic boost to normal keratinocytes and induced stasis to melanoma cells. The light and nanocomposite combination could be a potential therapy for bacterial keratosis or for skin tumors.

