The effect of gold quantum dots/grating-coupled surface plasmons in inverted organic solar cells

Bioinspired theranostic quantum dots: Paving the road to a new paradigm for cancer diagnosis and therapeutics

Despite extensive research, a complete cure remains lacking for most types of cancer. Nanotechnology-based carriers, such as liposomes, nanoparticles (NPs), dendrimers, nanoemulsions, and other nanocarriers, can target cancer cells, but their in vivo fate is unpredictable. Bioinspired quantum dots (BQDs) offer enhanced aqueous solubility, exceptionally low toxicity, biocompatibility, easy biofunctionalization, and selective cancer targeting. Due to their photoluminescence, high longitudinal relaxation value, photothermal effect upon laser irradiation, generation of singlet oxygen, and production of H2S for gas therapy, BQDs are excellent cancer theranostic agents. In this review, we highlight the theranostic application of, and existing challenges relating to BQDs.

Tunable surface plasmon resonance enhanced fluorescence via the stretching of a gold quantum dot-coated aluminum-coated elastomeric grating substrate

In this study, the surface plasmon resonance (SPR)-enhanced fluorescence properties of gold quantum dots (AuQDs) on an aluminum (Al)-coated polydimethylsiloxane (PDMS) grating substrate were investigated by changing the grating pitch via mechanical stretching. The SPR-excitation wavelength of the AuQDs/Al-coated PDMS-grating substrate was tuned by changing the incident light angle from 5° to 60° and stretching it from 0 to 1.0 mm. In addition, the SPR-enhanced fluorescence tuning ability was studied using an AuQD/Al-coated PDMS-grating film by stretching the substrate. The SPR-enhanced fluorescence (SPF) of the AuQDs on the Al-grating was observed using a violet laser as the excitation source at 405 nm with p-polarization. The wavelengths of the SPR excitation, corresponding to the SP-dispersion mode of +1, were shifted to a longer wavelength upon stretching the grating substrate from 0 to 1.0 mm. By stretching the AuQDs/Al-grating PDMS substrate, the SPR-enhanced fluorescence intensity increased at fixed incident angles of 15° and 35°, whereas the SPR-enhanced fluorescence intensity decreased at 40°. Moreover, the SPF could be tuned to exhibit different properties in tunable optical sensors.

Plasmonic photothermal properties of silver nanoparticle grating films

The plasmon-induced photothermal effect offers effective light-to-heat conversion systems. In this study, we fabricate plasmonic photothermal silver nanoparticle (AgNP) grating films to produce highly effective plasmon-induced heat generation films. AgNP films provide effective heat generation by localized surface plasmon excitation in the void of the AgNP films. The heat generated at a AgNP film by irradiation of solar light is 3.4 times higher than that generated at the reference flat evaporated-Ag film. Furthermore, simultaneous excitation of localized surface plasmons and propagating surface plasmons is confirmed to be obtained on AgNP grating films by finite-difference time-domain simulation and reflectivity measurements. The AgNP grating film is created by the nanoimprinting technique. The grating structure on AgNPs further enhances electric field intensity in the large area of the film, which results in higher heat generation. Thus, 5.4 times higher heat generation is achieved compared with that of the reference flat evaporated-Ag film.