Journal of Photochemistry and Photobiology C: Photochemistry Reviews最新文献

Photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) combine light and photosensitizers to treat cancers and microbial infections, respectively. In PACT, the excitation of a photosensitizer drug with appropriate light generates reactive oxygen species (ROS) that kill pathogens in the proximity of the drug. PACT has considerably advanced with new light sources, biocompatible photosensitizers, bioconjugate methods, and efficient ROS production. The PACT technology has evolved to compete with or replace antibiotics, reducing the burden of antibiotic resistance. This review updates recent advances in PACT, with special references to light sources, photosensitizers, and emerging applications to microbial infestations. We also discuss PACT applied to COVID-19 causing SARS-CoV-2 treatment and disinfecting food materials and water. Finally, we discuss the pathogen selectivity and efficiency of PACT.

Hydrogen plays an important role in developing a clean and sustainable future energy scenario. Substantial efforts to produce green hydrogen from water splitting, biomass and hydrogen sulfide (H₂S) have been made in recent years. H₂S, naturally occurring or generated in fuel gas processing and industrial wastewater treatment, can be split into hydrogen and sulfur via photocatalysis. Although it is not as widely used as water splitting for green hydrogen production, this process is considered to be an appropriate and sustainable way to meet the future energy demands, adding value to H₂S. Therefore, it is essential to understand how to improve the solar light utilization and splitting efficiency of H₂S based on the existing technology and materials. Along with that effort, molecular modeling and theoretical calculations are indispensable tools to provide guidance to effectively design photocatalysts for improving hydrogen generation efficiency. In this review, we summarize the published work on H₂S photocatalysis modeling and illustrate the use of different computational methods to gain more in-depth insight into the reaction mechanisms and processes. Moreover, an overview of quantum mechanical and molecular simulation approaches combined with other modeling techniques, relevant to material science and catalysis design and applicable to H₂S splitting is also presented. Challenges and future directions for developing H₂S splitting photocatalysts are highlighted in this contribution, which is intended to inspire further simulation developments and experiments for H₂S splitting, tailoring photocatalysts design towards highly efficient hydrogen production.

Over the years, microorganisms have developed several resistance mechanisms against standard treatments, thus limiting the effect of drugs and rendering ineffective therapies. Considering the growing number of resistant pathogens and adverse effects of conventional therapies, new antimicrobial technologies able to provide more effective, rapid, and safer treatments to inactivate pathogens, with unlikely chances of inducing resistance, are needed. In this regard, antimicrobial photodynamic inactivation (aPDI) has emerged as an alternative modality of treatment. In particular, Zn(II) porphyrins (ZnPs) hold great potential as photosensitizers (PSs) for aPDI and have been attracting increasing attention. The chemical structure of ZnPs can be tailored to produce PSs with improved chemical stability and photophysical properties, also modulating their amphiphilic and ionic characters, bioavailability, and (sub)cellular distribution. Thus, in this review, we provide a detailed report of studies published in about the last 10 years (2010–2021) focusing on aPDI mediated by ZnPs over a variety of pathogens, including bacteria, fungi, viruses, and protozoa. Fundamentals of aPDI, and porphyrin and its derivatives, especially ZnPs, are also included herein. We hope that this review can guide and be a reference for future studies related to aPDI mediated by ZnPs, and encourages more detailed studies on ZnP photophysical and photochemical properties, aiming to improve the fight against infectious diseases.

Solar energy conversion is inciting tremendous research efforts in many fields due to the vast potential of sunlight as a sustainable energy source. For solar energy to become widely used and become a major component of our energy mix, energy storage on large scales must be addressed and the components used must be abundant. Artificial photosynthesis to produce solar fuels holds promise as a way to convert solar energy into storable energy. Organic photocatalysts have rapidly established themselves as a viable alternative to inorganic systems. Organic photocatalyst can be prepared from inexpensive precursors and offer a synthetic versatility and tunability that can be exploited to improve efficiencies. Carbon nitride (CN_x) has emerged as a leading organic photocatalyst with advantageous chemical and photo stabilities. Recombination of photogenerated electrons and holes limit the efficiency of CN_x materials below levels necessary to become a viable energy production system. To improve the efficiency and key characteristics such as light harvesting, charge carrier lifetime, and interfacial rate of charge transfer, a second material is put in contact with CN_x to form a heterojunction. While there are many examples of heterojunctions improving the photocatalytic activity beyond that of the isolated CN_x, we are still lacking the deep understanding of charge carrier dynamics necessary to rationalize the improvements and design optimal junctions. This review covers the studies of CN_x heterojunctions that have used optical methods to monitor the charge carrier dynamics. Time-resolved photoluminescence (TRPL) is the most common technique used and there are many examples that have used transient absorption spectroscopy (TAS) to probe the charge carrier dynamics. However, attempting to link the lifetime change to the activity differences does not yield a clear trend. It is likely that the reactive charges are not consistently being monitored and is obscuring the expected correlations. Both shorter and longer charge carrier lifetimes can be observed with both TRPL and TAS techniques and can be interpreted as arising from interfacial charge separation. Even when the same materials are used in the junction there is no consistency in observing a shorter or longer lifetime. The holistic view of charge carrier dynamics in CN_x heterojunctions presented here intends to identify overarching themes from a wide range of CN_x-containing systems and help take stock of where our current understanding stands. More specific spectral assignments and linking the observed lifetimes to certain photophysical or photochemical processes are needed to build models to help us understand the links between the charge carrier dynamics and the activity. These are crucial to develop general strategies that will lead to optimal CN_x heterojunctions.

Cocrystallization has evolved as an attractive prospect to broaden the chemical landscape of a drug entity, expand its therapeutic scope, and address physicochemical deficiencies of an active pharmaceutical ingredient (API). The non-covalent approaches to address the solubility and bioavailability of BCS Class-II and Class-IV drugs is an archetypal example and is a prolific topic. The present review highlights various supramolecular methods employed in addressing the photoinstability in drugs, emphasizing crystal engineering approaches. Because a greater proportion of the drugs are formulated in the solid-state, the structural factors—crystal packing, intermolecular interactions, packing density—remain a critical determinant in the observed extent of stability. Comprehending and amending these structural determinants using crystal engineering concepts proposes to address the photoinstability in drugs. Also, we highlight the pros and cons of the different adopted strategies in terms of formulation and the underlying challenges and put in prospect. The review provides a correlative assessment of the structure-property relations that could further augment the foundations of factual knowledge in drug stability.

Perovskite solar cells (PSCs) fabricated with two-dimensional (2D) halide and 2D-3D mixed-halide materials are remarkable for their optoelectronic properties. The 2D perovskite structures are extremely stable but show limited charge transport and large bandgap for solar cell applications. To overcome these challenges, multidimensional 2D-3D perovskite materials are used to maintain simultaneously, a long-term stability, and high performance. In this review, we discuss the recent progress and the advantages of 2D and 2D-3D perovskite materials as absorber for solar cell applications. First, we discuss the structure and the unique properties of 2D and multidimensional 2D-3D perovskites materials. Second, the stability of 2D and 2D-3D mixed perovskites and the perspects of PSCs are hashed out.

Phthalocyanine (Pc) dyes are photoactive compounds that can absorb and emit light in a large range of the UV–vis spectrum, with recognized potential for medical applications. Considering the low solubility of Pc macrocycles in water, it is important to use cationic symptoms on their skeleton to improve their amphiphilicity for biomedical applications. The use of suitable pyridinium groups on Pc is a good strategy to solve this drawback and make them more eff ;ective to photoinactivate microorganisms via a photodynamic inactivation (PDI) approach. This review focuses the synthesis of quaternized Pc dyes, their photophysical and photochemical properties, and their antimicrobial photoinactivation efficiency. This innovative study compares, for the first time, different cationic moieties on Pc taking into account the efficiency of singlet oxygen (¹O₂), quantum yield (Φ_Δ) generation, fluorescence quantum yield (Φ_F), (photo)stability, light irradiation type (visible/white and/or red light), maximized overlapped absorption effect of Pc (S- and/or Q-band) vs light system irradiation type, and water solubility (n-octanol/water partition coefficient, P_o/w), when these parameters are determined and provided in the multidisciplinary reports. This approach is also relevant to conjugate free-base (H₂Pc) and metalated phthalocyanines (MPc, M = Zn²⁺, Mg²⁺, In³⁺, Ga³⁺, Ge³⁺, Si⁴⁺, etc.) with aromatic or aliphatic substituents linked by N, O or S atoms on the peripheral or axial positions of the Pc structures, such as e.g. (methoxy, oxy, or thio)pyridinium, ammonium, or benzimidazolium units, etc. Here, the influence of the structural peripheral (α- and/or β-position of Pc) or axial substituents type, number and positive charge position that can affect the PDI process will be analysed. These aspects are important to design versatile molecules that can interact with pathogenic microorganisms of variable size, subcellular architecture, biochemical composition, and susceptibility to externally added chemical agents. This review highlights the important developments of several modifications of cationic Pc dyes for the PDI of microorganisms, such as pathogenic bacteria, fungi, and virus.