title: Optical properties of plasmon-resonant bare and silica-coated nanostars used for cell imaging.
abstract: We synthesized and characterized gold nanostars and their silica-coated derivatives with 7- to 50-nm shell thicknesses as contrast agents for optical imaging. The scattering and absorption coefficients of the nanoparticles (NPs) were estimated by means of collimated transmittance and diffuse reflectance/transmittance analyses. The contrasting properties of the nanostructures were studied in optical coherence tomography glass capillary imaging. The silica-coated nanostars with the thickest shell have higher scattering ability in comparison with bare nanostars. Viability assays confirmed weak in vitro toxicity of nanostructures at up to ∼200-μg/mL concentrations. We showed real-time visualization of nanostars in both agarose and cultured cells by analyzing the backscattering signal using a conventional laser confocal microscope. The signal intensity detected from the silica-coated NPs was almost 1.5 times higher in comparison with bare nanostars. To the best of our knowledge, this is the first time that conventional laser confocal microscopy was applied in combined scattering and transmitted light modes to detect the backscattered signal of gold nanostars, which is useful for direct monitoring of the uptake, translocation, and accumulation of NPs in living cells.
authors.affiliation: University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Electrical Engineering, Optoelectronics and Measurement Techniques Laboratory, 3 Erkki Koiso-Kanttilan katu, Oulu 90570, Finland.
authors.forename: Olga
authors.initials: O
authors.lastname: Bibikova
authors.affiliation: University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Electrical Engineering, Optoelectronics and Measurement Techniques Laboratory, 3 Erkki Koiso-Kanttilan katu, Oulu 90570, Finland.
authors.forename: Alexey
authors.initials: A
authors.lastname: Popov
authors.affiliation: University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Electrical Engineering, Optoelectronics and Measurement Techniques Laboratory, 3 Erkki Koiso-Kanttilan katu, Oulu 90570, Finland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bykov
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Science, 13 Prospect Entuziastov, Saratov 410049, Russian Federation.
authors.forename: Artur
authors.initials: A
authors.lastname: Prilepskii
authors.affiliation: University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Electrical Engineering, Optoelectronics and Measurement Techniques Laboratory, 3 Erkki Koiso-Kanttilan katu, Oulu 90570, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Kinnunen
authors.affiliation: University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Electrical Engineering, Microelectronics and Materials Physics Laboratories, 3 Erkki Koiso-Kanttilan katu, Oulu 90570, Finland.
authors.forename: Krisztian
authors.initials: K
authors.lastname: Kordas
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Science, 13 Prospect Entuziastov, Saratov 410049, Russian FederationdSaratov State University, Faculty of Nonlinear Processes, Corporate Department of Biophysics, 83.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Bogatyrev
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Science, 13 Prospect Entuziastov, Saratov 410049, Russian FederationdSaratov State University, Faculty of Nonlinear Processes, Corporate Department of Biophysics, 83.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Khlebtsov
authors.affiliation: University of Oulu, Faculty of Biochemistry and Molecular Medicine, Oulu Center for Cell-Matrix Research, Laboratory of Developmental Biology, 5A Aapistie, Oulu 90220, Finland.
authors.forename: Seppo
authors.initials: S
authors.lastname: Vainio
authors.affiliation: University of Oulu, Faculty of Information Technology and Electrical Engineering, Department of Electrical Engineering, Optoelectronics and Measurement Techniques Laboratory, 3 Erkki Koiso-Kanttilan katu, Oulu 90570, FinlandfSaratov State University, Facu.
authors.forename: Valery
authors.initials: V
authors.lastname: Tuchin
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D003584:Cytological Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry* / Q000633:toxicity; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry* / Q000633:toxicity; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D006046:Gold; D012822:Silicon Dioxide