ChemPhotoChem最新文献

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.

Chiral liquid crystals (LCs) are essential for optoelectronic devices. Two representative achiral luminescent compounds, pyrene and perylene, are doped into a mixed chiral nematic LC (N*-LC) comprising achiral LC 4′-pentyl-4-biphenylcarbonitrile (5CB) and chiral LC 2-octyl-4-[4-(hexyloxy)benzoyloxy]benzoate (2OHBB). Consequently, despite being achiral luminescent materials, the doped pyrene and perylene successfully generate strong circularly polarized luminescence (CPL) from the resulting chiral N*-LC composed of 5CB and 2OHBB. The rotation direction of the extracted CPL can be controlled by the chirality of the LC molecule 2OHBB. Furthermore, these N*-LCs demonstrate continuous and reversible CPL responses depending on the presence or absence of a direct current (DC) electric field. This result demonstrates the successful design of a CPL LC system, where the rotation direction of CPL can be controlled not only by the chirality of 2OHBB, but also through the ON–OFF–ON switching of the DC electric field. This behavior is attributed to a reversible transition from a helical structure to another ordered structure (chiral nematic phase to chiral nematic phase transition). This study provides an effective strategy for controlling CPL properties by exposing N*-LC to DC electric fields and for developing functional CPL devices.

A Ruddlesden–Popper phase-layered perovskite Fe₂SnO₄ is coupled with graphitic carbon nitride (gCN) in an S-scheme heterojunction. The Fe₂SnO₄/gCN heterojunction is synthesized using the sonication–calcination method. The layered structure of Fe₂SnO₄ enhances charge migration toward the junction interface and enables the internal electric field, increasing the charge separation in the overall composite. The optical characteristics of Fe₂SnO₄/gCN show an excellent visible light utilization ability, thus expanding its applicability in solar (visible light)-driven catalytic approaches. A significant formate generation rate (2.043 mM h⁻¹ gcat⁻¹) is measured over the photocatalyst using the aqueous bicarbonate as the CO₂ precursor. The isotope labeling test corroborates the generation of formate from bicarbonate. Fe₂SnO₄/gCN also displays a good stability over five reaction–regeneration cycles. The band structure of Fe₂SnO₄/gCN in conjunction with the radicals detected via spin trapping confirms the development of the S-scheme heterojunction in Fe₂SnO₄/gCN. Herein, the fabrication of the layered perovskite-based S-scheme heterojunction paves a path for pursuing the solar-driven environmental remediation strategies.