Search Results (170)

Nanoparticle-mediated photothermal conversion exploits the unique light-to-heat transduction properties of engineered nanomaterials to address challenges in energy, water, and healthcare. This review first examines fundamental mechanisms—localized surface plasmon resonance (LSPR) in plasmonic metals and broadband interband transitions in semiconductors—demonstrating how tailored nanoparticle compositions can achieve >96% absorption across 250–2500 nm and photothermal efficiencies exceeding 98% under one-sun illumination (1000 W·m⁻², AM 1.5G). Next, we highlight advances in solar steam generation and desalination: floating photothermal receivers on carbonized wood or hydrogels reach >95% efficiency in solar-to-vapor conversion and >2 kg·m⁻²·h⁻¹ evaporation rates; three-dimensional architectures recapture diffuse flux and ambient heat; and full-spectrum nanofluids (LaB₆, Au colloids) extend photothermal harvesting into portable, scalable designs. We then survey photothermal-enhanced thermal energy storage: metal-oxide–paraffin composites, core–shell phase-change material (PCM) nanocapsules, and MXene– polyethylene glycol—PEG—aerogels deliver >85% solar charging efficiencies, reduce supercooling, and improve thermal conductivity. In biomedicine, gold nanoshells, nanorods, and transition-metal dichalcogenide (TMDC) nanosheets enable deep-tissue photothermal therapy (PTT) with imaging guidance, achieving >94% tumor ablation in preclinical and pilot clinical studies. Multifunctional constructs combine PTT with chemotherapy, immunotherapy, or gene regulation, yielding synergistic tumor eradication and durable immune responses. Finally, we explore emerging opto-thermal nanobiosystems—light-triggered gene silencing in microalgae and poly(N-isopropylacrylamide) (PNIPAM)–gold nanoparticle (AuNP) membranes for microfluidic photothermal filtration and control—demonstrating how nanoscale heating enables remote, reversible biological and fluidic functions. We conclude by discussing challenges in scalable nanoparticle synthesis, stability, and integration, and outline future directions: multicomponent high-entropy alloys, modular photothermal–PCM devices, and opto-thermal control in synthetic biology. These interdisciplinary innovations promise sustainable solutions for global energy, water, and healthcare demands. Full article

This study presents a multifunctional theranostic platform based on anisotropic gold nanostars (AuNSs) functionalized with 2-thiouracil (2-TU) for cancer diagnostics and photothermal therapy (PTT). The unique plasmonic properties of AuNSs, combined with the anticancer and photothermal potential of 2-TU, were harnessed to create a system capable of simultaneous colorimetric biosensing and therapeutic action. Under dual-wavelength irradiation (660 nm and 525 nm), the AuNSs–2-TU conjugate demonstrated enhanced photothermal conversion efficiency, selective cancer cell targeting, and signal amplification, resulting in a significant reduction in the IC₅₀ for MCF-7 breast cancer cells. The system exhibited minimal cytotoxicity to normal fibroblasts (WS1), ensuring therapeutic precision. Compared to conventional spherical gold nanoparticles, this platform provides superior multifunctionality, including real-time biosensing with simple, naked-eye colorimetric readouts. These results highlight the potential of the AuNSs–2-TU conjugate as an innovative, minimally invasive nanotheranostic platform suitable for integrated cancer detection and treatment, particularly in resource-constrained settings. Full article

Objective: This study aims to engineer a novel nanoparticle formulation for combined tumor therapy, designated as PDA@Mn-siSur-c-NPs, which comprises a polydopamine/manganese dioxide (PDA@MnO₂) core alongside survivin-targeting siRNA and cyclo(RGD-DPhe-K)-targeting moiety. Methods: The PDA@Mn-siSur-c-NPs were constructed and subjected to detailed characterization. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was employed to quantify manganese content. To assess siRNA stability within the system, samples were incubated with 50% fetal bovine serum (FBS) before agarose gel electrophoresis analysis. Additionally, cellular internalization by 4T1 cells and in vitro photothermal conversion efficiency of the formulation were evaluated. ICP-OES was further utilized to investigate the in vivo pharmacokinetics and tissue distribution of manganese. Animal model studies were conducted to assess the anti-breast cancer efficacy of PDA@Mn-siSur-c-NPs in combination with infrared irradiation. Results: The newly developed PDA@Mn-siSur-c-NPs demonstrated superior siRNA protection, reduced toxicity, and high photothermal conversion capacity. When combined with photothermal therapy (PTT), these nanoparticles exerted enhanced synergistic anti-tumor effects. Delivery of survivin siRNA resulted in a significant downregulation of survivin protein expression in tumor tissues. Moreover, magnetic resonance imaging (MRI) confirmed that the nanoparticles possess favorable imaging properties. Conclusions: This research demonstrates that the integration of PDA@Mn-siSur-c-NPs with PTT holds considerable therapeutic promise for improved breast cancer treatment. Full article

Controllably propelling microbubbles in microchannels within a microfluidic chip is of great scientific significance yet remains challenging. In this work, we employ carbon nanocoils (CNCs) as a laser-energized rail for propelling microbubbles to the desired position on the inner sidewall of microchannels by laser irradiation at the liquid-CNC interface. Laser-controlled microbubbles can be generated, transported to a desired location, stopped, and re-mobilized repeatedly without a significant change in volume on the microchannel within a microfluidic chip by controlling the laser spot. The microbubbles exhibit a rolling motion at the liquid-CNC interface due to stronger convectional flow induced by a dynamic, mobile thermal gradient generated by a scanning laser spot. The photothermal conversion properties and hydrophobic surface of the CNCs enable the CNCs to function as a laser-energized rail for microbubble propulsion. These results demonstrate that laser-controlled microbubbles rolling on CNC rails have good mobility and can be accurately manipulated in a microchannel chip. This approach leverages a dynamic thermal gradient, departing from static control methods to enable on-demand, reconfigurable manipulation of microbubbles, which opens up new possibilities for lab-on-a-chip and microfluidic applications. Full article

Developing organic photothermal agents that are highly stable and have tunable electronic properties is important for advancing low-invasive cancer therapy. In this study, we present the synthesis and evaluation of three conjugated photothermal agents inspired by non-fullerene Y-series acceptors: the small molecule BTPT-OD, as well as two of its polymer derivatives with regular (r-BTPT) and irregular (ir-BTPT) structures. All of the compounds absorb light effectively in the red and near-infrared spectral ranges, with absorption maxima from 734 to 746 nm, and form stable nanoparticles (NPs) via nanoprecipitation, ranging in size from 13 to 39 nm. NPs exhibited negative surface charges, with ζ-potentials of −12.9, −15.5, and −17.9 mV for BTPT-OD, r-BTPT, and ir-BTPT NPs, respectively. Irradiation at a wavelength of 730 nm revealed that r-BTPT and ir-BTPT polymer NPs exhibited a 22- to 40-fold greater phototoxicity against A-549, Sk-Br-3, and MCF-7 human carcinoma cells than the non-polymeric analogue BTPT-OD. The measured photothermal conversion efficiencies ranged from 24 to 27 ± 5%. At the same time, the intracellular ROS generation quantified by the 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) assay was low, allowing us to propose heat-mediated photothermal therapy as a more significant cell death predictor than ROS-mediated photodynamic therapy. This work is one of the first to compare small and polymeric non-fullerene acceptor materials for phototherapy purposes, demonstrating the advantages of using polymers. Full article

Hydrogel-based solar-driven interfacial evaporators have recently emerged as high-efficiency and sustainable technology for desalination. By leveraging the unique three-dimensional network, remarkable hydrophilicity, and tunable physicochemical properties of hydrogels, these systems achieve efficient solar absorption and thermal conversion, significantly enhancing water evaporation rates. This review summarizes design strategies based on physical and chemical cross-linking, and explores key approaches for performance enhancement, including reduction of evaporation enthalpy and structural optimization. Through regulation of water states and construction of multi-scale porous and biomimetic architectures, synergistic improvements in photothermal conversion, water transport, and thermal management have been realized. Furthermore, hydrogel-based evaporators demonstrate great potential in integrated applications such as wastewater treatment, salt collection, and hydroelectric generation. Finally, challenges related to water purification applications are discussed. This review offers valuable insights for the future design of hydrogel-based solar evaporators to mitigate global water scarcity. Full article

MXenes are relatively new 2D materials made up of carbides and/or nitrides of transition metals with a chemical formula M_n+1X_nT_x. They are usually fabricated by chemically etching a ceramic phase. MXenes possess tunable catalytic, optical, and electronic properties, which have attracted significant research interest, primarily in energy storage and biosensing applications. Since their first fabrication in 2011, there has been a rapid increase in studies investigating the use of MXenes in a wide range of applications. In this review, the synthesis methods of MXenes are discussed. Then, the potential application of MXenes in cancer treatment is highlighted based on current research. The ability of MXene to convert light, usually NIR (I and II), to heat with improved conversion efficiencies makes it a competitive candidate for photothermal cancer therapy. Moreover, the surface of MXenes can be modified with drugs or nanoparticles, thereby achieving synergistic photo/chemo/, and sonodynamic therapy. This review also examines the available research on the biocompatibility and cytotoxicity of MXenes. Full article

Silver sulfide quantum dots (Ag₂S QDs) are promising nanomaterials for biomedical applications due to their near-infrared emission and biocompatibility. In this study, Ag₂S QDs were synthesized using bovine serum albumin (BSA) as a stabilizing and reducing agent to assess their potential in targeted photothermal therapy. The QDs showed an average size of 1.06 ± 0.38 nm by DLS and 4.42 nm by TEM. Conjugation to an anti-PSG1 monoclonal antibody was performed via EDC/Sulfo-NHS chemistry and confirmed by FTIR spectroscopy, a decrease in zeta potential, and a redshift in emission. The conjugate exhibited an average size of 22.82 ± 9.7 nm and a zeta potential of +85.7 mV, indicating high colloidal stability. Fluorescence studies showed that the conjugate emits at 590 nm when excited at 560 nm, whereas the BSA-Ag₂S QDs (non-conjugated) emit at 480 nm upon excitation at 400 nm, reflecting changes in optical properties due to conjugation. Thermal imaging under 808 nm laser irradiation revealed efficient photothermal conversion, with temperature increases up to 13.6 °C at 200 μg/mL and a conversion efficiency of 11.41 ± 0.04%. The conjugate was non-cytotoxic to fibroblasts but induced selective cytotoxicity in HeLa cells after laser exposure, with a selectivity index of 3.0. These findings suggest that Ag₂S-BSA QDs conjugated with anti-PSG1 represent promising candidates for further investigation in cancer nanotheranostics. Full article

The escalating crisis of bacterial antimicrobial resistance poses a severe threat to global health, necessitating novel strategies beyond conventional antibiotics. Photothermal therapy (PTT) has emerged as a promising alternative that leverages heat generated by laser irradiation to induce localized cellular damage and eradicate bacteria. Among various photothermal agents, carbon-based nanomaterials like graphene nanoplatelets (GNPs) offer exceptional properties for PTT applications. This study introduces a novel urinary catheter (UC) embedded with GNPs (GNPUC), specifically designed for photothermal sterilization to combat catheter-associated bacterial infections. GNPs were systematically incorporated into polydimethylsiloxane (PDMS) catheters at varying weight percentages (1% to 10%). The fabricated GNPUCs exhibited low wettability, hydrophobic characteristics, and low adhesiveness, properties that are crucial for minimizing bacterial interactions and initial adhesion. Upon exposure to near-infrared (NIR) laser irradiation (808 nm, 1.5 W/cm²), the UC containing 10 weight percent of GNPs (10GNPUC) achieved a significant temperature of 68.8 °C, demonstrating its potent photothermal conversion capability. Quantitative agar plate tests confirmed the enhanced, concentration-dependent photothermal antibacterial activity of GNPUCs against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Notably, 5% and higher GNP concentrations achieved 100% mortality of S. aureus, while 1% and higher concentrations achieved 100% mortality of E. coli. These findings underscore the significant potential of GNP-embedded catheters as a highly effective photothermal antibacterial platform for future clinical applications in combating catheter-associated infections. Full article

This review summarizes recent advances in photoactive nanomaterials containing metals and their biomedical applications, particularly in cancer diagnosis and therapy. Conventional approaches such as chemotherapy and radiotherapy suffer from low specificity, systemic toxicity, and resistance, while light-based therapies, including photothermal therapy (PTT) and photodynamic therapy (PDT), offer minimally invasive and localized alternatives. Metal nanomaterials, especially gold and silver, exhibit unique localized surface plasmon resonance (LSPR) effects that enable efficient light-to-heat or light-to-reactive oxygen conversion, supporting precise tumor ablation, drug delivery, and imaging. We discuss strategies for structural design, surface functionalization, and encapsulation to enhance stability, targeting, and therapeutic efficiency. Emerging hybrid systems, such as carbon-based nanostructures and metal–organic frameworks, are also considered for their complementary properties. Computational modeling tools, including finite element and discrete dipole approximations, are highlighted for predicting nanomaterial performance and guiding rational design. Finally, we critically assess challenges such as toxicity, long-term biocompatibility, and clinical translation, and provide perspectives for future development. By integrating materials design, simulation, and preclinical findings, this review aims to inform the advancement of safer and more effective nanotechnology-based platforms for personalized cancer treatment and diagnosis. Full article

The intensifying freshwater crisis underscores the critical need for all-weather, low-energy atmospheric water harvesting technologies. Inspired by the scale-like protrusions and interconnected channels of Tillandsia leaves that enable efficient water capture and release, a polyvinyl alcohol-based foam featuring a three-dimensional porous structure is fabricated using the supercritical carbon dioxide foaming technology. Compared to the traditional freeze-drying method, this approach significantly reduces preparation energy consumption and shortens the production cycle. Lithium chloride integration endows the foam with exceptional moisture absorption capacity, reaching 300% of its weight. Leveraging graphene’s outstanding photothermal conversion properties, the foam achieves a photothermal dehydration rate of 80.7% within 80 min under 1 Sun irradiation, demonstrating a rapid water release capacity. Furthermore, the polyvinyl alcohol-based foam exhibits no performance degradation after 60 cycles, indicating remarkable stability. This technology provides a scalable, low-cost, and all-climate-applicable solution for water-scarce regions. Full article

Cell membranes and the cytoskeleton play crucial roles in the regulation of cellular responses by mediating mechanical forces and physical stimuli from the microenvironment through their viscoelastic properties. Investigating these properties provides valuable insights into disease mechanisms and therapeutic strategies. Gold nanorods (GNRs), especially under irradiation, exhibit lethal effects against Leishmania parasites through plasmonic photothermal conversion. In this study, we focus on evaluating the effects of non-irradiated GNRs on macrophage properties to better understand their intrinsic interactions with cells and support the development of future phototherapy applications. Here, defocusing microscopy (DM), a quantitative phase microscopy technique, was used to analyze membrane fluctuations in macrophages ($M\varnothing s$) exposed to GNRs (average length of $43\pm 8 \mathrm{n}\mathrm{m}$ and diameter of $20\pm 4 \mathrm{n}\mathrm{m}$) and infected with Leishmania amazonensis. By quantifying membrane–cytoskeleton fluctuation from defocused images, we extracted viscoelastic parameters, including bending modulus ($k_c$) and viscosity ($\eta$), to characterize membrane behavior in detail. Our results show that infection increases both $k_c$ and $\eta$, while treatment at IC₅₀ reduces infection and selectively increases $k_c$ without affecting $\eta$. In healthy macrophages, exposure to GNRs resulted in a reduction in both parameters, indicative of increased membrane fluidity and cytoskeletal rearrangement. These findings provide new insights into the biomechanical effects of GNRs on macrophages and may enlighten the design of future phototherapeutic approaches. Full article

Solid–liquid phase change materials (PCMs), promising for thermal management, face limited application due to leakage and low thermal conductivity. In this work, a shape-stabilized composite PCM was fabricated using a one-pot in situ process by mixing polyethylene glycol (PEG) with the novel metal–organic network called CFK, which was synthesized from carboxylated multi-walled carbon nanotubes (CMWCNTs), FeCl₃, and Kevlar nanofibers (KNFs). The morphology, composition, and thermophysical characteristics of the composite PCM were assessed. Key properties analyzed to validate its performance included leakage rate, thermal conductivity, latent heat, light absorption, photothermal conversion efficiency, and cycling stability. This composite PCM exhibits reduced leakage while maintaining remarkable thermal energy charge/discharge performance. The study establishes that the composite PCM containing 89.9 wt% PEG has a leakage rate of 0.76% since the PEG molecules are deeply embedded in the pores of CFK. The thermal conductivity of this composite PCM was enhanced by 170.5% relative to pure PEG, and the latent heat was measured as 147.9 J·g⁻¹ for fusion and 143.7 J·g⁻¹ for crystallization. Additionally, this composite PCM reveals excellent light absorption capacity, a photothermal conversion efficiency as high as 83.4%, and outstanding stability in photothermal cycling experiments. In short, this work offers a new strategy for both preparing high-performance composite PCMs and applying them in visible light conversion. Full article

Interfacial solar evaporation has emerged as a promising strategy for freshwater production, where 3D evaporators offer distinct advantages in heat management and salt rejection. Freeze–thaw cycling is a widely adopted fabrication method for 3D hydrogel evaporators, yet the impact of preparation conditions (e.g., freezing temperature) on their evaporation performance remains poorly understood, hindering rational optimization of fabrication protocols. Herein, we report the fabrication of chitosan-based hydrogel evaporators via freeze–thaw cycles at different freezing temperatures (−20 °C, −40 °C, and −80 °C), leveraging its low cost and environmental friendliness. Characterizations of crosslinking density and microstructure reveal a direct correlation between freezing temperature and network porosity, which significantly influences evaporation rate, photothermal conversion efficiency, and anti-salt performance. It is noteworthy that the chitosan hydrogel prepared at −80 °C demonstrates an excellent evaporation rate in high-salinity environments and exhibits superior salt resistance during continuous evaporation testing. Long-term cyclic experiments indicate that there was an average evaporation rate of 3.76 kg m⁻² h⁻¹ over 10 cycles, with only a 2.5% decrease observed in the 10th cycle. This work not only elucidates the structure–property relationship of freeze–thaw fabricated hydrogels but also provides a strategic guideline for tailoring evaporator architectures to different salinity conditions, bridging the gap between material design and practical seawater desalination. Full article

Photothermal therapy (PTT) is one of the rapidly developing methods for cancer treatment based on the strong light-to-heat conversion by nanoparticles. Over the past decade, the palette of photonic materials has expanded drastically, and nanoparticle fabrication techniques can now preserve the optical response of a bulk material in produced nanoparticles. This progress potentially holds opportunities for the efficiency enhancement of PTT, which have not fully explored yet. Here we study the photothermal performance of spherical nanoparticles (SNs) composed of novel two-dimensional (2D) and conventional materials with existing or potential applications in photothermal therapy such as MoS₂, PdSe₂, Ti₃C₂, TaS₂, and TiN. Using the Mie theory, we theoretically analyze the optical response of SNs across various radii of 5–100 nm in the near-infrared (NIR) region with a particular focus on the therapeutic NIR-II range (1000–1700 nm) and radii below 50 nm. Our calculations reveal distinct photothermal behaviors: Large (radius > 50 nm) nanoparticles made of van der Waals semiconductors and PdSe₂ perform exceptionally well in the NIR-I range (750–950 nm) due to excitonic optical responses, while Ti₃C₂ nanoparticles achieve broad effectiveness across both NIR zones due to their dual dielectric/plasmonic properties. Small TiN SNs excel in the NIR-I zone due to the plasmonic response of TiN at shorter wavelengths. Notably, the van der Waals metal TaS₂ emerges as the most promising photothermal transduction agent in the NIR-II region, particularly for smaller nanoparticles, due to its plasmonic resonance. Our insights lay a foundation for designing efficient photothermal transduction agents, with significant implications for cancer therapy and other biomedical applications. Full article