ChemPhotoChem最新文献

Photoelectrochemical hydrogen production is a promising and cost-effective strategy to provide clean and sustainable fuel. Due to its excellent electrical and optical properties, tungsten trioxide (WO₃) is one of the most studied electrode materials in this field, and it is well known that the incorporation of pores into the semiconductor can improve its photoelectrochemical performance. Using a facile and scalable template-assisted sol–gel technique, porous WO₃ thin films were tailored by simply varying the number of dip coating cycles. By crystallizing these films at 400 °C, a $$-orthorhombic/$$-monoclinic crystal structure and an average surface area of 32 m² g⁻¹ were obtained. By optimizing the layer thickness of these photoanodes on fluorine-doped tin oxide, photocurrents of up to 3.3 mA cm⁻² at 1.23 V_RHE (in 0.1M H₂SO₄, pH = 0.71) were achieved without the use of any co-catalysts or sacrificial agents. Our photoelectrodes also showed highly reproducible photocurrents, and their high stability was proven in cycling tests, long-term measurement and post-photoelectrochemical characterization. Our work represents a very simple preparation optimization to achieve high-performing WO₃ photoanodes for photoelectrochemical applications.

Photodynamic therapy (PDT) is a noninvasive therapeutic approach for treating cancer and various other diseases. A PDT system relies on three key components: a light source, photosensitizers (PSs), and oxygen. Conventional PDT, which utilizes external light sources to activate PSs, has already been approved for clinical use. However, external light has limited tissue penetration depth and may sometimes cause photoallergic reactions. As a result, internal light sources, such as chemiluminescence (CL) and bioluminescence (BL), have emerged as promising alternatives for future PDT applications. In this review, recent advances in CL/BL-based PDT systems over the past five years are summarized and future trends and design strategies are proposed to guide further research. Specifically, 1) “All-in-one”; 2) covalent linkage; 3) direct PDT for CL-based PDT systems and 1) fusion protein; 2) gene transfection and 3) engineered microorganisms for BL-based PDT systems are discussed. Among these strategies, the “All-in-one” approach—which encapsulates all necessary components within a single delivery system—is possibly the most feasible for optimizing PDT efficacy and the easiest to integrate with chemotherapy or immunotherapy. To advance CL/BL-based PDT toward clinical translation, further evaluation is needed regarding the toxicity and cost of well-designed systems.

The extensive use and improper disposal of nitro-antibiotics in veterinary medicine pose significant environmental and health risks, necessitating sensitive and selective detection methods. Furthermore, distinguishing between nitroimidazoles and nitrofurans remains challenging. Here, an amino acid-scaffolded metal nanocluster-based differential nitro-antibiotic detection strategy leveraging the inner filter effect (IFE) is presented. Nanoclusters are engineered to align with the distinct absorption maxima of nitroimidazoles (λ_abs^max = 320 nm) and nitrofurans (λ_abs^max = 370 nm). L-tyrosine-capped silver nanoclusters (Tyr-Ag NCs) (excitation/emission: 320/410 nm) showed significant photoluminescence (PL) quenching in response to both nitro-antibiotics classes, enabling a turn-off-based detection method. In contrast, L-tryptophan- and L-cysteine-capped copper nanoclusters (Trp-Cu and Cys-Cu NCs), with excitation/emission around 380/500 nm, overlapped spectrally only with nitrofurans, enabling selective quenching and simple visual detection without instrumentation. All three NCs demonstrated nanomolar sensitivity, high selectivity, and minimal interference from non-target species, with their detection mechanisms elucidated in detail. The practicality of the assay is validated through the successful detection of nitro-antibiotics in cow milk and groundwater, demonstrating its reliability in real-world samples. Overall, this study establishes a strategic sensing platform that intentionally leverages the IFE—traditionally considered an experimental artifact—as a powerful and selective tool for antibiotic detection.

Organic room-temperature phosphorescence (RTP) materials have received considerable research interest in photoelectric devices, sensing and imaging, and information encryption owing to the advantageous properties, including low toxicity, broad structural tunability, outstanding processability, and good biocompatibility. Despite the progress made in the past two decades, obstacles such as limited material structure and complex regulation processes are still persisting. In this minireview, the research advances in the RTP of propeller-like organic molecules according to the molecular skeleton will be summarized. Future perspectives and remaining challenges will be discussed at the end.

Optical readouts have gained a considerable attention due to their high spatial resolution, high signal to noise ratio and fast response times. Among these, light-emitting diodes (LEDs) as optical transducers enable to encode chemical information in the current passing through the diode and as a consequence in its light emission amplitude. Recently, the synergy between the principle of bipolar electrochemistry and the optical and electric advantages of LEDs have been explored, in order to develop novel and straightforward approaches to visualize chemical information. This has been increasingly exploited in multiple applications ranging from electroanalysis to chiral recognition, dynamic systems, and multimodal imaging. This review aims to highlight the use of endogenous (thermodynamically spontaneous) and exogenous (externally driven) bipolar electrochemistry for the design of wireless optical readouts based on the operating principle of LEDs.

A new concept for fluorescent probes capable of reporting on the concentrations of weak bases in aqueous solution was recently reported, and suggested as a potential tool for studying cellular buffer systems and metabolite pools (Jakobsen et al., Chem Sci, 2025, 16, 7450). These probes are based on proton coupled electron transfer (PCET) quenching of a phenol substituted diazaoxatriangulenium (DAOTA⁺) fluorophore, promoted by the weak bases acting as proton acceptors for the phenol group. The fluorescence lifetime is reduced as function of the proton transfer (PT) rate and base concentration. Herein, we report the synthesis of a new series of related DAOTA+ probes designed to elucidate the involvement of water bridges in PT. The 5-hydroxy-3-benzoic acid substituted DAOTA⁺ probe showcases intramolecular PT that can only happen by water bridging between the carboxylate proton acceptor and phenol donor groups. This exemplifies how the PCET based PT probes can be designed to investigate the role of Grotthuss-like water bridges in acid/base reactions. Furthermore, the negatively charged carboxylate group, through electrostatic repulsion, prohibits ground state association between the probe and negatively charged bases. These new probes showcase a further development of dynamic PCET probes for studies of PT rates in complex systems.

In this work, a semi-automated pipeline for the transition state search of molecular switches (PiTS³) is reported, which facilitates the search, optimization, and conformational analysis of transition states of user-generated molecular structures. This tool is oriented towards the casual user interested in simulating the thermal properties of photochemical switches. Hence, the pipeline can easily read the commonly used .cdxml files as input, and leverages different established packages such as ORCA, xTB, CREST, and pysisyphus. Additional scripts are provided to combine different inputs to create libraries of compounds from chemical drawings, to explore large chemical spaces of photoswitches based on the stilbene, imine, aza-diarylethene, and norbornadiene structures.

For the first time, an unconventional sunlight-induced photocatalytic protocol for the synthesis of deep-blue light emissive carbazolyl-α-aminophosphonates (CAPs) (4) via a solvent-free Kabachnik–Fields reaction under open air atmosphere has been developed. The reaction is assumed to proceed through a single electron transfer mechanism. The prepared photocatalyst, TiO₂ nanowires has been characterized by X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy analysis. Nature-friendly reaction profile, simple to perform, use of a renewable energy source, shorter reaction times, good functional group tolerance, excellent yields (91–98%), scalability, reuse of photocatalyst, products do not need chromatographic purification, and the green chemistry metrics are close to the ideal values are the notable advantages of the present MCR strategy. Therefore, the present approach is very close to the theory of “benign by design” concept. Further, the photophysical and electrochemical behavior of CAPs (4) are examined. The results indicate that the synthesized bifunctional (hole-transporting and deep-blue light emitters) CAPs (4) could be promising materials for the construction of economical and efficient blue light-emitting organic optoelectronic devices.

Cost-effective and efficient photocatalysis is highly desirable in chemical synthesis. Here a honeycomb-like porous carbon nitride (P-C₃N₄) with defects was prepared by a simple one-step calcination of an aqueous urea solution. By introducing the hierarchical porous structure and defects, the P-C₃N₄ was able to make more efficient use of visible light and enhance mass transfer. This catalyst exhibits 44% longer carrier lifetime than bulk C₃N₄ and can be easily scaled up and demonstrates excellent catalytic reactivity in various types of cross-dehydrogenative coupling (CDC) reactions under visible light irradiation. A very high reaction rates of 6467 and 10,625 μmolg⁻¹h⁻¹ were achieved by P-C₃N₄ in model reaction of aza-Henry type and Mannich type of CDC reaction, which are 26.8 and 2.8 times higher than previous reports, respectively. Moreover, P-C₃N₄ can maintain 95% yield of target product in aza-Henry CDC reaction after 21 cycles of repeated experiments. Our low-cost, easy-to-process, and highly efficient C₃N₄ photocatalyst is expected to bring new insights in chemical synthesis.

A novel ratiometric fluorescent platform, composed of a rodamine derivative and dansyl moiety, is designed and synthesized as a prototype sensor capable of responding to proton concentration. It is well known that, under neutral or basic conditions, rhodamine derivatives in their spirolactam form do not absorb or emit in the visible range. However, metal or proton ions can induce spirolactam ring opening, resulting in visible absorption and strong fluorescence emission. Although many rhodamine derivatives have been developed to detect metal ions or pH changes, the sensing mechanism related to spirolactam ring opening remains not fully understood. To address this, the hybrid platform described in this work is investigated across a wide pH range, particularly under high proton concentration, to study and clarify the proton-mediated ring opening mechanism of the rhodamine spirolactam. This investigation combined spectrophotometric and potentiometric measurements, supported by DFT calculations.