A Carbon Nanodot Based Near-Infrared Photosensitizer with a Protein-Ruthenium Shell for Low-Power Photodynamic Applications

Nanoengineering Carbon Dot-Polymer Brush Interfaces for Adaptive Optical Materials

We present a versatile platform for fabricating two-photon excitable carbon dot-based nanocomposite thin films by harnessing the structural versatility of polymer brushes in combination with electron-beam lithography (EBL). This approach enables the precise spatial organization of carbon dots (CDs) at the nanoscale, facilitating dynamic modulation of their photoluminescent properties in response to environmental stimuli. Three model systems were examined, incorporating pH- and thermally responsive polymers, functionalized through covalent and dynamic covalent bonding strategies. By leveraging the spatial control afforded by nanostructured polymer brushes, we achieved precise tuning of optical properties while mitigating aggregation-induced quenching, a longstanding challenge in solid-state CD applications. In addition to the advances in controlling optical properties, this work highlights the potential of polymer brush systems to function as optically active, reprogrammable surfaces. The resulting nanoscale-engineered materials exhibit highly responsive, reconfigurable photonic behavior, offering a scalable pathway for integrating advanced optical interfaces into microchip technologies, biosensing platforms, and multiplexed diagnostic systems. The fusion of polymer brushes, carbon dots, and advanced lithographic techniques marks a substantial advancement in the development of functional materials with nanoscale precision and stimuli-responsive properties.

Advance of Near-Infrared Emissive Carbon Dots in Diagnosis and Therapy: Synthesis, Luminescence, and Application

Carbon dots (CDs) with good optical properties, biocompatibility, easy functionalization, and small size have attracted more and more attention and laid a good foundation for their applications in the biomedicine field. CDs emitted in near-infrared regions (NIR-CDs) can achieve high penetration depth imaging and produce high cytotoxic substance for disease treatment. Therefore, NIR-CDs are promising materials to realize high-quality imaging-guided diagnostic and therapeutic integration. This review first introduces the current mainstream synthesis methods of NIR-CDs by "top-down" and "bottom-up". Second, the luminescence modes of NIR-CDs are introduced, and the luminescence mechanisms based on carbon core state, surface state, molecular state, and crosslinking enhanced emission are summarized. Third, the applications and principles of NIR-CDs in imaging, drug delivery, and non-invasive therapeutics are introduced from a view of diagnosis and therapy. Finally, their prospects and challenges in biomedical and biotechnological applications are outlined.

Leveraging the Photofunctions of Transition Metal Complexes for the Design of Innovative Phototherapeutics

Despite the advent of various medical interventions for cancer treatment, the disease continues to pose a formidable global health challenge, necessitating the development of new therapeutic approaches for more effective treatment outcomes. Photodynamic therapy (PDT), which utilizes light to activate a photosensitizer to produce cytotoxic reactive oxygen species (ROS) for eradicating cancer cells, has emerged as a promising approach for cancer treatment due to its high spatiotemporal precision and minimal invasiveness. However, the widespread clinical use of PDT faces several challenges, including the inefficient production of ROS in the hypoxic tumor microenvironment, the limited penetration depth of light in biological tissues, and the inadequate accumulation of photosensitizers at the tumor site. Over the past decade, there has been increasing interest in the utilization of photofunctional transition metal complexes as photosensitizers for PDT applications due to their intriguing photophysical and photochemical properties. This review provides an overview of the current design strategies used in the development of transition metal complexes as innovative phototherapeutics, aiming to address the limitations associated with PDT and achieve more effective treatment outcomes. The current challenges and future perspectives on the clinical translation of transition metal complexes are also discussed.

Carbon dots as a novel photosensitizer for photodynamic therapy of cancer and bacterial infectious diseases: recent advances

Carbon dots (CDs) are novel carbon-based nanomaterials that have been used as photosensitizer-mediated photodynamic therapy (PDT) in recent years due to their good photosensitizing activity. Photosensitizers (PSs) are main components of PDT that can produce large amounts of reactive oxygen species (ROS) when stimulated by light source, which have the advantages of low drug resistance and high therapeutic efficiency. CDs can generate ROS efficiently under irradiation and therefore have been extensively studied in disease local phototherapy. In tumor therapy, CDs can be used as PSs or PS carriers to participate in PDT and play an extremely important role. In bacterial infectious diseases, CDs exhibit high bactericidal activity as CDs are effective in disrupting bacterial cell membranes leading to bacterial death upon photoactivation. We focus on recent advances in the therapy of cancer and bacteria with CDs, and also briefly summarize the mechanisms and requirements for PSs in PDT of cancer, bacteria and other diseases. We also discuss the role CDs play in combination therapy and the potential for future applications against other pathogens.

Near-Infrared Dyes: Towards Broad-Spectrum Antivirals

Broad antiviral activity in vitro is known for many organic photosensitizers generating reactive oxygen species under irradiation with visible light. Low tissue penetration of visible light prevents further development of antiviral therapeutics based on these compounds. One possible solution to this problem is the development of photosensitizers with near-infrared absorption (NIR dyes). These compounds found diverse applications in the photodynamic therapy of tumors and bacterial infections, but they are scarcely mentioned as antivirals. In this account, we aimed to evaluate the therapeutic prospects of various NIR-absorbing and singlet oxygen-generating chromophores for the development of broad-spectrum photosensitizing antivirals.