Near-infrared Light Absorption Research Articles

Analysis on factors affecting the cooling effect of optical shielding in pavement coatings

Inspired by transparent heat-shielding research, three tungsten bronze nanoparticles (i.e., nano-cesium tungsten bronze (Cs0.3WO3), nano-sodium tungsten bronze (Na0.28WO3) and nano-potassium tungsten bronze (K0.26WO3)) with excellent near-infrared light absorption properties were applied for the first time to prepare pavement coatings so as to alleviate the temperature-related damage of pavement and urban heat island effect. X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible–near infrared spectrometer (UV/VIS/NIR), self-made indoor simulated solar radiation apparatus were employed in this research to study the application of nano tungsten bronze into pavement, as well as its benefit. It was found that the solar reflectivity of the coating is between 3.22% and 6.29%, which is very close to that of asphalt binder, which is 5.24%. The coating made of Cs0.3WO3 nanoparticles reduced the temperature most significantly among all specimens, and the combination of theoretical optimal cooling effect was determined. The correlation between the temperature rising value of the specimen coated with the most effective coating and that of the control specimen was established, which provided a basis for predicting the cooling value of the coating.

Rapid and sensitive detection of PD-L1 exosomes using Cu-TCPP 2D MOF as a SPR sensitizer

Two-dimensional metal organic framework (2D MOF Cu-TCPP) with significantly enhanced photoelectric properties was synthesized by a simple hydrothermal method. The π-stacked electroactive porphyrin molecules of TCPP-based 2D MOF carry out charge transport in the MOF structure. The d-d band transition of Cu2+ and its 2D ultra-thin characteristics can produce excellent near-infrared light absorption to couple with SPR. Three key parameters including the refractive index sensitivity, detection accuracy and quality factor were improved significantly for 2D MOF modified gold chips. Especially, the refractive index sensitivity was increased from 98 to 137.67°/RIU after modified with 2D MOF. Thus, for the first time, we applied it as a signal enhancer to improve direct SPR assay for the Programmed death ligand-1 (PD-L1) exosomes. Owning to its large specific surface area, excellent photoelectric properties, highly ordered structure, good dispersion and biocompatibility, the LOD of the SPR sensor was 16.7 particles/mL. The reliability and practicability were further validated by analysis of PD-L1 exosomes in human serum samples. The recovery rate was 93.43 %–102.35%, with RSD of 5.79 %–14.6%. Given their excellent signal amplification ability, 2D MOF Cu-TCPP could serve as an ideal SPR sensitizer for rapid and sensitive detection of trace disease markers.

Exploration of New Sensitizers for Photodynamic Therapy Targeting Deep Cancer Treatment

Despite its advantages, photodynamic therapy (PDT) has one major drawback: penetration depth. This limits the use of conventional PDT methods to skin (surface) tumors only, making it ineffective for deep tumors. There are four possible solutions for the light delivery for deep tumor treatment: particles activated by near-infrared (NIR) light, up-conversion of nanoparticles that absorb NIR light and emit visible light for other photosensitizers (PSs), fiber optics and ionizing X-rays. Of these options, the best is X-rays. Near-infrared light can penetrate only 5[Formula: see text]mm in tissue while retaining enough energy to activate the PSs. The use of fiber optics is neither convenient nor efficient as it cannot effectively and evenly activate the photosensitizers. It is also almost impossible for the treatment of metastatic sites or lymph nodes involved with this disease, unless they are located in the region where light delivery is feasible. In contrast with the other methods, X-rays can easily penetrate as deeply as necessary into the patients, and are convenient as they are commonly used in cancer therapy. The use of novel copper–cysteamine (Cu–Cy) nanoparticles is a good solution for overcoming these issues because Cu–Cy nanoparticles can be effectively activated by X-rays to produce singlet oxygen, which makes it very efficient for deep cancer treatment. Here, I will discuss the use of copper–cysteamine nanoparticles to enhance radiation therapy in combination with PDT and targeting therapies.

DFT calculation in design of near-infrared absorbing nitrogen-doped graphene quantum dots.

The near-infrared light (NIR) absorption of nitrogen-doped graphene quantum dots (NGQDs) containing different N-doping sites is systematically investigated with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations with Perdew-Burke-Ernzerhof (PBE) functionals. The results show that the ultra-small HOMO-LUMO gaps (0.3-1.0 eV) of various N-doping structures (graphitic, amino, and pyridinic at center, and graphitic at edge) are attributed to the spin-polarization of the energy states, which effectively enhances the NIR absorption for NGQDs. Overall, the graphitic N-doping structure exhibits the best NIR absorption. Moreover, the electron attraction effect of the different N-sites is found to be crucial for the LUMO level, where stronger electron attraction lowers the LUMO energy. This work provides critical insight in further design of NGQDs for NIR absorption.

A 2D nanotheranostic platform based on graphene oxide and phase-change materials for bimodal CT/MR imaging, NIR-activated drug release, and synergistic thermo-chemotherapy.

Recent years have seen considerable progress in the development of nanomedicine by the advent of 2D nanomaterials serving as ideal platforms to integrate multiple theranostic functions. We synthesized multifunctional stimuli-responsive 2D-based smart nanocomposites (NCs), comprising gold nanoparticles (AuNPs) and superparamagnetic iron oxides (SPIOs) scaffolded within graphene oxide (GO) nanosheets, coated with doxorubicin (DOX)-loaded 1-tetradecanol (TD), and further modified with an alginate (Alg) polymer. TD is a phase-change material (PCM) that confines DOX molecules to the GO surface and melts when the temperature exceeds its melting point (Tm=39 °C), causing the PCM to release its drug payload. By virtue of their strong near-infrared (NIR) light absorption and high photothermal conversion efficiency, GO nanosheets may enable photothermal therapy (PTT) and activate a phase change to trigger DOX release. Upon NIR irradiation of NCs, a synergistic thermo-chemotherapeutic effect can be obtained by GO-mediated PTT, resulting an accelerated and controllable drug release through the PCM mechanism. The biodistribution of these NCs could also be imaged with computed tomography (CT) and magnetic resonance (MR) imaging in vitro and in vivo. Hence, this multifunctional nanotheranostic platform based on 2D nanomaterials appears a promising candidate for multimodal image-guided cancer therapy.

Photovoltaic performance of novel Perovskite/organic integrated solar cells with high efficiency and high stability

Perovskite/organic integrated solar cell possesses the perovskite active layer with wide band gap that can absorb high energy photons, while the lower energy photons can pass through the perovskite layer and be absorbed by the organic active layer with narrow band gap. By introducing a Bulk heterojunction (BHJ) consisting of perovskite materials and near-infrared (NIR) organic semiconductor materials in the visible light region, the enhanced short-circuit current density of organic cells can be obtained while maintaining the high open-circuit voltage of perovskite-type devices. We prepare perovskite/organic integrated solar cells by directly deposing the narrow band gap organic active layer PC<sub>20</sub>BDTDPP:PC<sub>71</sub>BM on CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>. The CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>/PC<sub>20</sub>BDTDPP:PC<sub>71</sub>BM integrated solar cell can widen the perovskite absorption spectra, thereby increasing the near-infrared light absorption. The results show that the short-circuit current density of the integrated solar cell increases to 23.90 mA/cm<sup>2</sup>, the optical response is widened to 920 nm, the external quantum efficiency reaches 85% in the visible region, and is close to 55% in the near infrared region (800–900 nm), and the energy conversion efficiency of the device increases up to 20.30%. The integrated current density, quantum efficiency, and energy conversion efficiency of the best device are the highest values ever reported in perovskite/organic integrated solar cells. At room temperature of 25 ℃ and humidity of 30%, the efficiency of the device decreases to 95% of the original efficiency after 350 h, showing excellent device stability. The results show that it is an effective method to improve the near-infrared absorption of perovskite solar cells and improve the performance of perovskite/organic integrated solar cells through material combination and device structure optimization. The present research provides theoretical guidance and experimental basis for the development of perovskite/ organic integrated cells with high efficiency and stability in the future.

High-Performance Near-Infrared Photodetectors Based on the Synergy Effect of Short Wavelength Light Filter and Long Wavelength Response of a Perovskite/Polymer Hybrid Structure.

Near-infrared photodetectors (NIR-PDs) are widely used in communications, biomedical imaging, and national defense. Here we report a new strategy to prepare a short wavelength light filter based NIR-PDs by introducing an interface layer between the perovskite layer and the polymer layer to achieve the selective passage of carriers. Through the synergistic effect of the perovskite and the interface layer, the short wavelength light component in the signal spectrum is effectively filtered out. The organic polymer layer with a bulk heterojunction structure is applied to realize the absorption and conversion of near-infrared light. The prepared device achieves a maximum external quantum efficiency of 83.7% without bias, a high specific detectivity of 1.52 × 1013 Jones, an NIR responsivity of 0.577A/W, and a short response time of 1.73/0.97 μs within the detection range from 770 to 900 nm. All these properties show great advantages compared with other perovskite/polymer hybrid NIR photodetectors that have been reported. This innovative strategy provides a new way to prepare high-performance near-infrared photodetectors.

Extending Absorption of Cs2AgBiBr6 to Near‐Infrared Region (≈1350 nm) with Intermediate Band

AbstractThe toxicity of lead‐based halide perovskites hampers broad application in optoelectronics. Lead‐free perovskite Cs2AgBiBr6 is considered a promising candidate, owing to the long carrier lifetime and great stability. However, the relatively large bandgap of 1.98 eV limits its absorption in the visible region. Herein, Fe2+ is chosen as the dopant to alloy into Cs2AgBiBr6 single crystals, and results in an absorption range broadening to ≈1350 nm, which is the longest near‐infrared (NIR) response recorded among lead‐free perovskites. About 1% of Fe ions are alloyed into the Cs2AgBiBr6 lattice to cause lattice shrink age. Instead of narrowing the bandgap, Fe doping would introduce a new intermediate band inside the pristine bandgap of Cs2AgBiBr6 to strongly absorb NIR light, as confirmed by third harmonic generation results. Moreover, considerable photogenerated carriers are produced in Fe doped Cs2AgBiBr6 crystals with NIR irradiation. This work has provided a new way to extend the optical response of lead‐free perovskites for NIR photodetectors and intermediate band photovoltaics.

Photoisomerization of Linear and Stacked Isomers of a Charged Styryl Dye: A Tandem Ion Mobility Study.

The photoisomerization behavior of styryl 9M, a common dye used in material sciences, is investigated using tandem ion mobility spectrometry (IMS) coupled with laser spectroscopy. Styryl 9M has two alkene linkages, potentially allowing for four geometric isomers. IMS measurements demonstrate that at least three geometric isomers are generated using electrospray ionization with the most abundant forms assigned to a combination of EE (major) and ZE (minor) geometric isomers, which are difficult to distinguish using IMS as they have similar collision cross sections. Two additional but minor isomers are generated by collisional excitation of the electrosprayed styryl 9M ions and are assigned to the EZ and ZZ geometric isomers, with the latter predicted to have a π-stacked configuration. The isomer assignments are supported through calculations of equilibrium structures, collision cross sections, and statistical isomerization rates. Photoexcitation of selected isomers using an IMS-photo-IMS strategy shows that each geometric isomer photoisomerizes following absorption of near-infrared and visible light, with the EE isomer possessing a S1 ← S0 electronic transition with a band maximum near 680 nm and shorter wavelength S2 ← S0 electronic transition with a band maximum near 430 nm. The study demonstrates the utility of the IMS-photo-IMS strategy for providing fundamental gas-phase photochemical information on molecular systems with multiple isomerizable bonds.

Photocatalytic H2O2 production and removal of Cr (VI) via a novel Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure with broad spectral response

The low-usage of solar energy and the sluggish separation efficiency of the photogenerated electrons/holes pairs are the obstacles in the practical application of photocatalysts. The integration of upconversion and Z-scheme heterojunction is expected to break the barriers to achieve the efficient charge separation and broaden near-infrared light absorption. Herein, an effective indirect Z scheme AgInS2/In2S3 heterostructure with carbon quantum dots (CQDs, as the electron conduction medium) and Lu3NbO7:Yb, Ho (as upconversion function) has been successfully synthesized. Consequently, the Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure exhibited superior photocatalytic activities for Cr(VI) reduction and H2O2 production, reducing 99.9% of Cr(VI)(20 ppm, 15 min) and 78.5% of Cr(VI) (40 ppm, 30 min) with visible light irradiation as well as 94.0% of Cr(VI) (20 ppm, 39 min) under NIR light irradiation. Simultaneously, the heterostructure could generate 902.9 μM H2O2 for 5 h under visible light irradiation. The intensive photocatalytic properties could primarily be attributed to the boosted light absorption capacity, the improved solar-to-energy conversion by the remarkable upconversion capacity of Lu3NbO7: Yb, Ho/CQDs and the faster charge transfer through a Z-schematic pathway. This work is anticipated to open a novel “window” for designing the efficient photocatalysts by coupling of Lu3NbO7: Yb, Ho and CQDs.

Fabrication and characterization of Cesium-doped Tungstate nanorods for Near-Infrared light absorption in dye sensitized solar cells

Near-infrared (NIR) light-absorbing materials have been widely used in vehicle and building applications due to their transparent film structure with a high absorption rate in the NIR range and a high transmittance rate for visible light. In this paper, Cesium-doped Tungstate (Cs0.33WO3) has been combined with dye-sensitized solar cell (DSSC) to convert the heat energy (absorbed from NIR light) into photocurrent. Cs0.33WO3 Nanorods were synthesized and embedded in the active layer of the cell. The mesoporous Titanium dioxide (TiO2) on FTO has also been used as the electron transport layer (ETL). This simple structure of FTO/TiO2/Cs0.33WO3 resulted in a poor Fermi level alignment and a low voltage. However, a buffer layer made of Poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN-DOF) improved the Fermi level alignment and the quality of the interface in the modified structure of FTO/TiO2/PFN-DOF/Cs0.33WO3 which improved the initial Jsc from 0.38 μA/cm2 to 0.45 μA/cm2 for the NIR range. In addition, the Jsc of this modified structure improved from 18.84 μA/cm2 to 27.56 μA/cm2 for the visible light. Finally, by using a P25-doped TiO2 layer, the Jsc increased from 0.70 μA/cm2 to 31.12 μA/cm2 for both NIR and visible light, respectively.

IR-inspired visual display/response device fabricated using photothermal liquid crystals for medical and display applications

Combined applications of composite materials are very important in today’s science, especially those of liquid crystal (LC) materials. Visualization of near-infrared (NIR) with zero power consumption using a combination of photothermal and LC materials is urgently needed. In this study, a device was constructed from thermosensitive cholesteric LC (CLC) and nano-level polypyrrole materials, and named a photothermal polypyrrole nano-pigment-integrated with CLC (PNCLC) display element. A change in the reflected light of the CLC display element was achieved by the photoabsorption-exothermic characteristics of polypyrrole, which absorbs NIR light to drive the photothermal performance. The temperature and color change caused by the absorption of NIR light resulted in the CLC display element automatically indicating a change in the NIR intensity. In addition, to increase the range of potential applications, conductive soft polyethylene terephthalate (PET) substrates were used as display elements. To the best of our knowledge, this is the first study to illustrate a visual display element of NIR light intensity with zero power consumption and explore its potential theranostic applications.

Constructing a plasma-based Schottky heterojunction for near-infrared-driven photothermal synergistic water disinfection: Synergetic effects and antibacterial mechanisms

Developing green and highly efficient water disinfection technique is of great importance to public health. Herein, a near-infrared (NIR) light-triggerable thermo-sensitive defective molybdenum oxide-nitrogen doped carbon (MoO3-x/NCNs) composite was fabricated and applied to water disinfection. With the synergy of photodynamic and photothermal effects, the MoO3-x/NCNs achieve a rapid and effective inactivation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to photocatalytic treatment or thermal catalytic alone. Particularly, MONC-3 with optimal ratio can completely inactivate 7.6 log of E. coli and S. aureus within 60 min and 100 min, respectively. The MONC-3 hybrid exhibits efficient charge separation and migration ability due to the formation of Schottky heterojunction, resulting in the highly enhanced O2− (11.34 × 10−10 M) generation activity. Meanwhile, excellent NIR light absorption and photothermal conversion efficiency (52.6%) of MONC-3 can generate local high temperature to promote photocatalytic reaction rate and destruct the bacterial integrity. The monitoring of cell damage process confirmed the irreversible death of bacteria. Based on density functional theory (DFT) calculation, the antibacterial mechanism and Schottky effect were clarified. This work provides new insights for constructing a water disinfection strategy based on plasma-induced photothermal synergy catalysis.

Shape memory self-healing coating based on photothermal effect of PPy@PDA nanoparticles

PPy@PDA nanoparticles, prepared by varying ratios of PPy and dopamine hydrochloride, could be used as near infrared (NIR)-absorbing photothermal agents given that the UV–vis–NIR light absorption spectra showed a broad absorption band at 800–900 nm. A NIR-induced shape memory-assisted self-healing epoxy resin coating was obtained, and its shape memory effect was investigated by 808 nm NIR irradiation. Results indicated that the addition of PPy@PDA nanoparticles improved the shape recovery behavior of the composite. The self-healing property of the coatings was investigated by electrochemical test. Results of linear sweep voltammetry (LSV) and electrochemical impedance spectra (EIS) verified that the coating with 5 wt% PPy@PDA nanoparticles had a much better light-induced shape memory effect, self-healing performance, and protective capability than those of other contents of PPy@PDA nanoparticles. Moreover, the shape memory effect of the coating should be affected by the corrosion product of the metallic substrate.

Nitric oxide release activated near-Infrared photothermal agent for synergistic tumor treatment

Activatable phototherapeutic agents (PTA) in one system with synergistic gas therapy (GT) and photothermal therapy (PTT) hold great promise for highly efficient tumor treatments. In this study, an activatable multifunctional platform with photothermal conversion “turn on” features via nitric oxide (NO) release for synergistic GT and PTT was rationally designed using an aryl N-nitrosamine (NO-donating unit) functionalized aza-BODIPY framework (S–NO). As expected, after NO release from S–NO, the product (Red-S) showed obviously enhanced heat production performance under a longer excited wavelength via improved near-infrared light absorption and decreased fluorescence emission. Furthermore, water-soluble and biocompatible S–NO nanoparticles (S–NO NPs) with negligible dark cytotoxicity successfully suppressed tumor growth and enhanced the survival rate of mice via synergistic GT and PTT under the guidance of multimode imaging. The study offered rational guidance to design better platforms for synergistic tumor treatments and validated that S–NO NPs can act as potential PTAs in biological applications.

Near-Infrared-Triggered Nitrogen Fixation over Upconversion Nanoparticles Assembled Carbon Nitride Nanotubes with Nitrogen Vacancies.

Photocatalytic artificial fixation of N2 to NH3 occurs over NaYF4:Yb,Tm (NYF) upconversion nanoparticles (NPs) decorated carbon nitride nanotubes with nitrogen vacancies (NYF/NV-CNNTs) in water under near-infrared (NIR) light irradiation. NYF NPs with a particle size of ca. 20 nm were uniformly distributed on the surface of NV-CNNTs. The NYF/NV-CNNTs with 15 wt % NYF exhibited the highest NH3 production yield of 1.72 mmol L-1 gcat-1, corresponding to an apparent quantum efficiency of 0.50% under NIR light illumination, and about three times higher the activity of the bare CNNTs under UV-filtered solar light. 15N isotope-labeling NMR results confirm that the N source of ammonia originates from the photochemical N2 reduction. The spectroelectrochemical measurements reveal that NVs can greatly facilitate the photogenerated electron transfer without energy loss, while the presence of NYF NPs shifts both the deep trap state and the edge of conduction band toward a lower potential. Moreover, NYF NPs endow the photocatalyst with a NIR light absorption via the fluorescence resonance energy transfer process, and NVs have the ability to enhance the active sites for a stronger adsorption of N2 and decrease the surface quenching effect of NYF NPs, which thus can promote the energy migration within the heterojunctions. This work opens the way toward full solar spectrum photocatalysis for sustainable ammonia synthesis under aqueous system.

The synergistic effect of enhanced photocatalytic activity and photothermal effect of oxygen-deficient Ni/reduced graphene oxide nanocomposite for rapid disinfection under near-infrared irradiation

The rational design of high antibacterial efficiency are urgently needed as the occurrence of drug-resistance issues. Hence, Ni/reduced graphene oxide nanocomposite (Ni/rGO) with different amounts of oxygen vacancies were fabricated for efficient disinfection. The optimized Ni/rGO (A100) exhibited highly effective inactivation efficacy of 99.6% and 99.5% against Escherichia coli and Bacillus subtilis within 8 min near-infrared (NIR) irradiation through the synergistic effects of photothermal therapy and oxidative damage, which were much higher than single treatment. The A100 nanocomposite achieved an extraordinary photothermal conversion efficiency (35.78%) under the 808 nm irradiation for enhanced photothermal hyperthermia, thereby destroying the cell membrane and accelerating the GSH depletion. The radical scavenger experiment confirmed that •O2- and •OH play the chief role in photodisinfection reaction. Besides, A100 could exert significant damage on the ATP synthesis. The excellent photothermal performance and photocatalytic activity can be attributed to the appropriate oxygen vacancy density, which improves the absorption of NIR light and facilitates the separation of photogenerated electron-hole pairs. Besides, the higher NiO content of A100 contributed to improving the photocatalytic effect. Our work demonstrated a promising strategy for efficient water pollution purification caused by pathogenic bacteria.

Gold-embellished mixed-valence manganite as a smart, self-regulating magnetoplasmonic nanomaterial

In the present study, lanthanum-strontium manganite (LSM) particles were embellished with gold nanoparticles to create a magnetoplasmonic composite core-shell material enabling bimodal heating regimens upon exposure to an alternate current (AC) magnetic field and/or near-infrared (NIR) radiation. The composite particles were prepared by combined solid-state synthesis, mechanochemical processing and wet chemistry. The core crystals were round but faceted, often growing into an equilibrium shape conforming to the Wulff construction and the orthorhombic Pbnm crystal symmetry. They were also multi-domain but nanocrystalline, exhibiting superparamagnetic behavior as the result of evening the local anisotropies by the exchange interaction. The deposition of the gold nanoparticles onto the manganite core resulted in the red shift of the localized surface plasmon resonance due to interfacial effects. This deposition also improved the conditions for colloidal stability in water by increasing the surface charge density in the electric double layer surrounding the particles. The hybrid magnetoplasmonic particles were evaluated for their potential for use in cancer ablation therapies by measuring their aqueous heating dynamics in an ultralow AC magnetic field mimicking the magnetic hyperthermia (MH) condition of deep-seated tumors and the NIR light mimicking the photothermal (PT) condition. Aggregation of spherical, 5–10 nm sized gold nanoparticles on the surface of LSM enhanced their NIR light absorption capacity. The heating of the particle suspensions was more intense in the PT mode than in the MH mode, but the latter mode allowed for the display of the smart, thermostatic behavior by the material. Namely, the stoichiometry of the manganite phase, La0·76Sr0·24MnO3, was adjusted to display the Curie temperature at 45.8 °C after decoration with gold and the thermostatic effect at 43–44 °C, with a potential to prevent the overheating of tissues during the MH treatments of cancer. The bimodal heating potential endows the particles with the ability to be used in personalized cancer therapies. These therapies would be able to adjust in situ the ratio between the two heating modes, one more suitable for superficial ablation (PT) and another one for the treatment of deeper tumors (MH).

Folic Acid-Conjugated Gold Nanostars for Computed Tomography Imaging and Photothermal/Radiation Combined Therapy

Fabrication of multifunctional nanoprobes, which integrate tumor targeting, imaging, and effective treatment, has been widely explored in nanomedicine. In the present study, we fabricated tumor-targeting polymer folic acid-terminated polyethylene glycol thiol-modified gold nanostars (GNS-FA), which could realize X-ray computed tomography (CT) imaging and PTT/RT synergistic therapy. The synthesized GNS-FA exhibited good biocompatibility. GNS-FA could be used as a CT imaging contrast agent due to the strong X-ray attenuation of Au. GNS-FA exhibited good near-infrared (NIR) light absorption and excellent photothermal conversion performance, making them promising photothermal transduction agents (PTAs). Furthermore, GNS-FA could be used as an RT sensitizer to enhance the radio-mediated cell death due to the high atomic number (high Z) of gold. Hence, GNS-FA were used as the CT imaging agent, PTA, and radiosensitizer in this work. The in vitro antitumor experiments showed that the PTT/RT combined treatment had enhanced anticancer efficacy compared with the monotherapy (PTT or RT). Our results indicated that the bioconjugated GNS could offer an excellent nanoplatform for CT imaging-guided PTT/RT combined cancer therapy in the future.

Transparent selective photothermal coatings for antifogging applications

Surface fogging reduces light transmission of optically clear materials and causes various problems in daily life. Transparent photothermal materials have recently emerged as an eco-friendly and sustainable solution to surface fogging. However, most reported photothermal materials only exploited the broadband spectrum of solar energy, and the spectral feature has yet to be tuned to optimize the visibility and photothermal effect simultaneously. Here, we develop a highly transparent, photothermally selective coating, based on solution-processed cesium-doped tungsten trioxide nanoparticles. The transparent selective photothermal coating provides a visible transmittance up to 82% and a high absorption of ultraviolet and near-infrared light >90%, and achieves a temperature increase by 38°C under 1-sun illumination, resulting in remarkable antifogging and defogging abilities under extremely frigid or humid conditions. Large-scale complex surfaces with photothermal coatings are deployed in field antifogging tests as well as long-term durability tests, showing their great potential in antifogging applications.