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Photothermal Transduction Efficiencies of Plasmonic Group 4 Metal Nitride Nanocrystals
摘要： The photothermal transduction e?ciencies of group 4 metal nitrides, TiN, ZrN, and HfN, at λ = 850 nm are reported, and the performance of these materials is compared to an Au nanorod benchmark. Transition metal nitride nanocrystals with an average diameter of ～15 nm were prepared using a solid-state metathesis reaction. HfN exhibited the highest photothermal transduction e?ciency of 65%, followed by ZrN (58%) and TiN (49%), which were all higher than those of the commercially purchased Au nanorods (43%). Computational studies performed using a ?nite element method showed HfN and Au to have the lowest and highest scattering cross section, respectively, which could be a contributing factor to the e?ciency trends observed. Furthermore, the changes in temperature as a function of illumination intensity and solution concentration, as well as the cycling stability of the metal nitride solutions, were studied in detail.
关键词： nanocrystals,plasmonic,photothermal transduction,metal nitrides,Au nanorods
更新于2025-09-23 15:21:01
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Guanosine Assembly Enabled Gold Nanorods with Dual Thermo- and Photoswitchable Plasmonic Chiroptical Activity
摘要： Noble metal nanostructures with plasmonic circular dichroism (PCD) have attracted interest and a modulation of PCD is of great importance for their potential applications. Herein, we propose a supramolecular strategy for achieving dual thermal and photo-switchable PCD. When guanosine (G), deoxyguanosine (dG) and boric acid modified achiral gold nanorods (GNRs) were co-assembled into hydrogel, hybrid nanofibers with PCD were produced. When the hydrogel was heated, the nanofiber was disassembled and the PCD disappeared. Since the hydrogel was thermally reversible, a thermo-controlled PCD could be realized. The hybrid hydrogel also showed photo-switchable PCD. When the gel was irradiated with IR laser, the PCD disappeared. It can be restored by placing at room temperature. Moreover, the hybrid gel was selectively response to the circularly polarized light (CPL). For (G/dG)-GNRs hybrid assemblies, the R-CPL irradiation showed higher photothermal efficiency than that of L-CPL, which made it useful for an IR-irradiation controlled release of drug molecules.
关键词： plasmonic chirality,gold nanorods,guanosine,circular polarized light,selective response
更新于2025-09-23 15:21:01
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Plasmonic nano-dumbbells for enhanced photothermal and photodynamic synergistic damage of cancer cells
摘要： The longitudinal surface plasmon resonance of light-irradiated gold nanorods (Au NRs) is generated to enhance the local electric ?elds of Au NR-based nano-dumbbells (NDs), tailored speci?cally by coating mesoporous silica at two poles of Au NRs and embedding photosensitizer indocyanine green (ICG) into the mesopores. The assembled NDs possess a superior uniformity and water dispersity with a strong plasmonic absorption around 800 nm. Time-domain ?nite-difference calculations indicate that the enhanced local electric ?eld of NDs is predominantly distributed in the dumbbells at two poles of Au NRs, which improves the photonic performance of ICG signi?cantly. Illuminated by an 800 nm laser, the fabricated NDs demonstrate an enhanced combination of photothermal and photodynamic effects in comparison to either Au NRs or ICG alone. Synergistic damaging of photothermal and photodynamic combination to nasopharyngeal carcinoma cells has been corroborated experimentally, thus causing substantial cell death under a lower incident near-infrared laser power. This study concludes that the plasmonic NDs combined synergistically with ef?cient photothermal and photodynamic effects are highly promising in cancer therapy.
关键词： photodynamic therapy,photothermal therapy,cancer cells,gold nanorods,indocyanine green,Plasmonic nano-dumbbells
更新于2025-09-23 15:21:01
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Drug Delivery System Using Photothermal Effect of Gold Nanorods
摘要： Gold nanorods have absorption bands in the near-infrared region. The absorbed light energy is converted into heat by gold nanorods. Therefore, drug delivery systems that can be controlled by the heat produced by near-infrared light irradiation will be constructed. First, we modified gold nanorods with double-stranded DNA. That is, release of single stranded DNA is induced by the produced heat from the gold nanorods. We also constructed a controlled release system of PEG chain mediated by retro Diels-Alder reaction induced by the photothermal effect. Next, we designed transdermal protein delivery system enhanced by the photothermal effect. We first casted gold nanorods, acting as a heating device in response to near-infrared light irradiation, onto the skin surface. After applying an aqueous solution of ovalbumin to the skin, the skin was irradiated by near-infrared laser light. The irradiation increased the skin temperature resulting in an efficient translocation of ovalbumin into the skin. Thus, the controlled-release systems and enhanced transdermal protein delivery system triggered by near-infrared light irradiation will be further expanded to development of functional drug delivery system.
关键词： photothermal effect,gold nanorods,transdermal protein delivery,drug delivery system,near-infrared light
更新于2025-09-23 15:21:01
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Carbon quantum dots-decorated TiO2/g-C3N4 film electrode as a photoanode with improved photoelectrocatalytic performance for 1,4-dioxane degradation
摘要： In this study, carbon quantum dots (CQDs) were used to decorate a TiO2/g-C3N4 (TCN) film electrode. The morphological, optical, and electrochemical properties of the TiO2/g-C3N4/CQDs nanorod arrays (TCNC NRAs) film were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and electro-impedance spectroscopy (EIS). The improved optical properties, photoelectrochemical chemical properties and photoelectrocatalytic (PEC) performance of photoanode can be observed by doping CQDs onto the TCN NRAs film. Compared with TiO2 NRAs and TCN NRAs, the narrower band gap of 2.47 eV and longer lifetime of photoinduced electron-hole pairs were observed in the TCNC NRAs. Under visible light irradiation and a bias voltage of 1.2 V, the photocurrent density and 1,4-dioxane (1,4-D) removal rate of PEC process with TCNC NRAs electrode reached 0.16 mA/cm2 and 77.9%, respectively, which was 2.5 times and 1.5 times of that with TCN NRAs electrode. TCNC NRAs electrode could keep >75% of the 1,4-D removal rate during five cycles tests. High PEC performance with TCNC NRAs electrode could be attributed to the enhanced charge separation and the change of electron transfer mechanism from typical heterojunction to Z-scheme, which may increase the active species production and change the dominant reactive species from O2?- to ?OH. Our experimental results should be useful for studying the degradation of 1,4-D and developing efficient PEC materials.
关键词： Graphite carbon nitride,TiO2 nanorods,1,4-Dioxane,Carbon quantum dots,Photoelectrocatalysis
更新于2025-09-23 15:21:01
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Solar Cells with High Short Circuit Currents Based on CsPbBr <sub/>3</sub> Perovskite-Modified ZnO Nanorod Composites
摘要： 3-D all-inorganic perovskite solar cells have been built using vertically aligned conductive zinc oxide nanorods as the electron transport layer and optical waveguide. Yttrium doping improved the conductivity and hence the electron transportation of the ZnO achieving a threefold improvement of the solar cell efficiency. The vertically aligned nanorods act as optical waveguides and a scaffold, which improved photoabsorption of the perovskite semiconductor by increasing layer thickness. Our device structure was completed with an exfoliated multilayer graphite back contact for effective hole-extraction. The ZnO was most significantly modified by nanometre scale coatings of TiO2 in order to passivate the surface and reduce charge recombination, as measured by photoluminescence spectroscopy. This led to greatly improved charge transfer. This strategy led to an overall nine times enhancement in the solar cell efficiency, yielding a competitive top value of 5.83%. More importantly, the all-inorganic solar cells demonstrated excellent stability, showing no decline in initial performance after 1000 hour storage in ambient conditions. This work presents yttrium doped ZnO nanorods as a suitable replacement for mesoporous TiO2, achieving a high short circuit current of 10.5 mA cm-2 for CsPbBr3 perovskite devices.
关键词： Graphite,ambient synthesis,Inorganic perovskite,TiO2 coating,ZnO nanorods
更新于2025-09-23 15:21:01
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siRNA Delivery Using Dithiocarbamate-Anchored Oligonucleotides on Gold Nanorods
摘要： We present a robust method for loading small interfering RNA (siRNA) duplexes onto the surfaces of gold nanorods (GNRs) at high density, using near-infrared (NIR) laser irradiation to trigger their intracellular release with subsequent knockdown activity. Citrate-stabilized GNRs were first coated with oleylsulfobetaine (OSB), a zwitterionic amphiphile with low cytotoxicity, which produced stable dispersions at high ionic strength. Amine-modified siRNA duplexes were converted into dithiocarbamate (DTC) ligands and adsorbed onto GNR surfaces in a single incubation step at 0.5 M NaCl, simplifying the charge screening process. The DTC anchors were effective at minimizing premature siRNA desorption and release, a common but often overlooked problem in the use of gold nanoparticles as oligonucleotide carriers. The activity of GNR?siRNA complexes was evaluated systematically against an eGFP-producing ovarian cancer cell line (SKOV-3) using folate receptor-mediated uptake. Efficient knockdown was achieved by using a femtosecond-pulsed laser source to release DTC-anchored siRNA, with essentially no contributions from spontaneous (dark) RNA desorption. GNRs coated with thiol-anchored siRNA duplexes were less effective, and also permitted low levels of knockdown activity without photothermal activation. Optimized siRNA delivery conditions were applied toward the targeted knockdown of transglutaminase 2 (TG2), whose expression is associated with the progression of recurrent ovarian cancer, with a reduction in activity of over 80% achieved after a single pulsed laser treatment.
关键词： dithiocarbamates,siRNA,gold nanorods,zwitterionic surfactant,photothermal
更新于2025-09-23 15:21:01
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Dual coupled effects of low concentration gold nanorods on energy transfer and luminescence enhancement in Eu/Tb co-doped films
摘要： Eu/Tb co-doped films with low concentration gold nanorods have been prepared using the solution process. The luminescence spectra investigations indicate that the introduction of nanorods can effectively enhance the energy transfer from Tb to Eu under excitation of 292 nm, because of the plasmonic coupling with excited Tb complex. Under excitation of 360 nm, the emission at 612 nm is enhanced, the enhancement factor increases and then decreases as the molar ratio of Tb and Eu increases. The luminescence enhancement is attributed to the metal enhanced luminescence resulting from plasmonic coupling with excited Eu complex. The dual effects of LSPR on energy transfer and emission enhancement are both observed. More details on the luminescence of Eu/Tb co-doped films with nanorods are demonstrated, which gain a deeper understanding of the interactions luminescent-particle and luminescent-luminescent.
关键词： Enhanced luminescence,Eu,Plasmonic nanorods,Tb,Energy transfer
更新于2025-09-23 15:21:01
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The morphology regulation and plasmonic spectral properties of Au@AuAg yolk-shell nanorods with controlled interior gap
摘要： Au@AuAg yolk-shell nanorods with tunable and uniform interior gap were synthesized through galvanic replacement reaction, where Au@Ag core-shell nanorods served as sacrificial templates and HAuCl4 solution served as reductant. The effects of HAuCl4, Ag shell thickness and aspect ratio (AR) of Au nanorods on the morphology of Au@AuAg yolk-shell nanorods had been investigated systemically. The results clearly indicated that AuAg alloy shell thickness of Au@AuAg yolk-shell nanorods could be increased from 3.6 to 10.0 nm by varying the amount of HAuCl4. Meanwhile, the shape of AuAg alloy shell could be tuned by changing the shape of Ag coating. With the increasing of Ag coating thickness, the interior gap could be finely tuned in the range from 2.6 to 8.1 nm. The uniformity of interior gap could be improved by increasing the AR of Au nanorods. All these tunable geometries can further affect the plasmonic spectral properties of Au@AuAg yolk-shell nanorods. Because of the appearance of interior gap, the longitudinal localized surface plasmon resonance (LSPR) peak of Au@AuAg yolk-shell nanorods was located between that of bare Au nanorods and Au@Ag core-shell nanorods without interior gap. The increase of outer AuAg shell thickness can weaken the coupling between the inner and outer surface of the AuAg shell and lead to the decrease of AR, so the transverse and longitudinal LSPR bands gather together. The decrease of Ag coating thickness can enhance the coupling between inner Au nanorod and outer AuAg shell, which results in the red shift of the longitudinal LSPR band. This paper provides a method for studying the plasmonic coupling between two metal surfaces with a metal layer or a dielectric layer, which is also a new approach for regulating the plasmonic spectral properties of bimetallic nanoparticles. The controllability of Au@AuAg yolk-shell nanorods in both the interior gap and outer alloy shells makes them have potential applications in biomedicine, catalysis, nanoreactors, and energy storage.
关键词： interior gap,localized surface plasmon resonance,spectral properties,morphology regulation,Au@AuAg yolk-shell nanorods
更新于2025-09-23 15:21:01
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Defects Type Dependent Near-Infrared-Driven Photocatalytic Bacterial Inactivation by Defective Bi2S3 nanorods
摘要： Defects engineering is crucial in tailoring the photocatalytic efficiency, but it suffers from uncertainty to determine the vacancy type, and it is confusing which type of the vacancy can better promote the photocatalytic efficiency. In this study, Bi2S3 nanorods with bismuth or sulfur vacancies were synthesized respectively to investigate their distinct effects on the electronic structure, electron-hole separation characteristics and near-infrared (NIR)-driven photocatalytic bacterial inactivation activity. Both bismuth and sulfur vacancies can enhance the light absorption ability of Bi2S3. However, the life span of photoinduced electrons is extended by bismuth vacancy but shortened by sulfur vacancy. Due to these advantages, the bismuth vacant Bi2S3 can fully inactivated 7 log E. coli cells within 40 min of NIR irradiation, displaying a better NIR-driven photocatalytic bacterial inactivation efficiency than that of Bi2S3 with sulfur vacancy. This study disclosed the defects type dependent photocatalytic behaviors, providing new insights into designing highly efficient photocatalyst.
关键词： defect type dependent efficiency,near-infrared-driven photocatalysts,defective Bi2S3 nanorods
更新于2025-09-23 15:21:01