Stripping of the Positive-tone Diazonaphthoquinone / Novolak Resist using Laser Irradiation from Visible to Near Infrared Wavelength

Potassium lithium niobate (KLN: K3Li2Nb5O15) films have been deposited on quartz glass by Pulsed laser deposition (PLD) technique using a stoichiometric KLN target as starting materials. By investigating the effects of both the oxygen pressure and the substrate temperature on the structure of KLN films, optimum parameters have been identified for the growth of high-quality KLN films. At 10Pa oxygen ambient pressure, tetragonal tungsten-bronze-type structure of KLN films with (310) preferred orientation can be achieved at substrate temperatures in the range of 700-800°C. Optical studies indicate that the films are highly transparent in the visible-near-infrared wavelength range.

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Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications

Sensors ◽

10.3390/s21227452 ◽

2021 ◽

Vol 21 (22) ◽

pp. 7452

Author(s):

Muhammad A. Butt ◽

Andrzej Kaźmierczak ◽

Cuma Tyszkiewicz ◽

Paweł Karasiński ◽

Ryszard Piramidowicz

Keyword(s):

Refractive Index ◽

High Performance ◽

Near Infrared ◽

Sol Gel ◽

Cost Effective ◽

Dip Coating ◽

Infrared Wavelength ◽

Refractive Index Sensing ◽

Sensing Applications ◽

Coating Method

In this paper, a novel and cost-effective photonic platform based on silica–titania material is discussed. The silica–titania thin films were grown utilizing the sol–gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica–titania ridge waveguide is investigated via the finite element method. Silica–titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU−1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.

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Bioactivity of PEGylated Graphene Oxide Nanoparticles Combined with Near-Infrared Laser Irradiation Studied in Colorectal Carcinoma Cells

Nanomaterials ◽

10.3390/nano11113061 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3061

Author(s):

Natalia Krasteva ◽

Dessislava Staneva ◽

Bela Vasileva ◽

George Miloshev ◽

Milena Georgieva

Keyword(s):

Colorectal Cancer ◽

Graphene Oxide ◽

Colorectal Carcinoma ◽

Cancer Cells ◽

Laser Irradiation ◽

Molecular Mechanisms ◽

Near Infrared ◽

Carcinoma Cells ◽

Infrared Light ◽

Mitochondrial Activity

Central focus in modern anticancer nanosystems is given to certain types of nanomaterials such as graphene oxide (GO). Its functionalization with polyethylene glycol (PEG) demonstrates high delivery efficiency and controllable release of proteins, bioimaging agents, chemotherapeutics and anticancer drugs. GO–PEG has a good biological safety profile, exhibits high NIR absorbance and capacity in photothermal treatment. To investigate the bioactivity of PEGylated GO NPs in combination with NIR irradiation on colorectal cancer cells we conducted experiments that aim to reveal the molecular mechanisms of action of this nanocarrier, combined with near-infrared light (NIR) on the high invasive Colon26 and the low invasive HT29 colon cancer cell lines. During reaching cancer cells the phototoxicity of GO–PEG is modulated by NIR laser irradiation. We observed that PEGylation of GO nanoparticles has well-pronounced biocompatibility toward colorectal carcinoma cells, besides their different malignant potential and treatment times. This biocompatibility is potentiated when GO–PEG treatment is combined with NIR irradiation, especially for cells cultured and treated for 24 h. The tested bioactivity of GO–PEG in combination with NIR irradiation induced little to no damages in DNA and did not influence the mitochondrial activity. Our findings demonstrate the potential of GO–PEG-based photoactivity as a nanosystem for colorectal cancer treatment.

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