title: Light induced toxicity of merocyanine 540-silica nanoparticle complex.
abstract: The electrostatic binding between the negatively charged lipophilic dye Merocyanine 540 and silica nanoparticles having 3-amino propyl groups at the surface has been characterized using absorption and fluorescence spectroscopy. The binding of the dye with the nanoparticle resulted in significant changes in its absorption spectra. Further the fluorescence intensity and lifetime gets enhanced by more than an order of magnitude. The results obtained suggest that this is due to the reduced photoisomerization rate of the dye bound to the nanoparticle. Consistent with the expectation that a reduction in the photoisomerization rate should enhance the singlet oxygen yield of the dye via intersystem crossing, the light induced toxicity of the dye-nanoparticle complex (tested with MCF cells) was observed to be higher compared to the free dye.
authors.affiliation: Laser Bio-Medical Applications and Instrumentation Division, Raja Ramanna Center for Advanced Technology, Indore 452013, M.P, India.
authors.forename: K
authors.initials: K
authors.lastname: Das
authors.forename: A
authors.initials: A
authors.lastname: Uppal
authors.forename: B
authors.initials: B
authors.lastname: Jain
authors.forename: B
authors.initials: B
authors.lastname: Bose
authors.forename: P K
authors.initials: PK
authors.lastname: Gupta
mesh_terms: D006801:Humans; D008027:Light; D053758:Nanoparticles / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D012822:Silicon Dioxide