Journal of Photochemistry and Photobiology A-chemistry最新文献

{"title":"Optimized PEG/eudragit-Zn4V2O9 nanostructures for effective catalytic and antibacterial activity with computational insights","authors":"Muhammad Ahmad ,&nbsp;Ali Haider ,&nbsp;Iram Shahzadi ,&nbsp;Anwar Ul-Hamid ,&nbsp;Muhammad Imran ,&nbsp;Muhammad Ali Khan ,&nbsp;Ghafar Ali ,&nbsp;Mohamed Mohamed Soliman ,&nbsp;Muhammad Ikram","doi":"10.1016/j.jphotochem.2025.116365","DOIUrl":"10.1016/j.jphotochem.2025.116365","url":null,"abstract":"<div><div>A low-temperature co-precipitation approach was used to synthesize polyethylene glycol (PEG) and eudragit (Eud) doped zinc vanadate (Zn₄V₂O₉) for effective methyl orange dye reduction and antibacterial activity. This study aimed to increase the catalytic and antibacterial efficacy of Zn₄V₂O₉, by providing more active sites, and charge transfer efficacy with dopants. Varying concentrations of PEG were doped into Eud-Zn₄V₂O₉, 3 % PEG/Eud-Zn₄V₂O₉ was optimized for catalytic activity and 6 % PEG/Eud-Zn₄V₂O₉ was optimized for antibacterial activity. Comprehensive characterizations revealed monoclinic crystal structure, polycrystalline behavior, reduced bandgap energy, and multiple morphologies of PEG/Eud-Zn₄V₂O₉. The optimized sample showed 97.85 % degradation of methyl orange with a reducing agent without the presence of light. 6 % PEG/Eud-Zn₄V₂O₉ proved to be an effective to be an effective antibacterial agent (inhibition zone 6.55 ± 0.02) against <em>S. aureus</em>. The docking analysis of Eud-doped Zn₄V₂O₉ and PEG/Eud-doped Zn₄V₂O₉ laid out the suppressive effects of DNA gyrase enzyme in <em>S. aureus,</em> besides their antibacterial properties.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116365"},"PeriodicalIF":4.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Poly (ionic liquid-co-acrylic acid)/oxidized carbon nitride (P/P/O) with enhanced photocatalytic and synergistic bacteriostasis performance","authors":"Zhiyong Tan ,&nbsp;Tingting Song ,&nbsp;Yucong Liu ,&nbsp;Haifeng Sun ,&nbsp;Yuhua Dai ,&nbsp;Jianxiang Yu","doi":"10.1016/j.jphotochem.2025.116367","DOIUrl":"10.1016/j.jphotochem.2025.116367","url":null,"abstract":"<div><div>Overconsumption of non-renewable energy sources has caused the energy crisis and environmental pollution. Photocatalytic technology can utilize solar energy as a driving force for the energy conversion. Herein, 1-vinyl-3-ethylimidazolium tetrafluoroborate (VEImBF₄) and acrylic acid (AA) were used as monomers to prepare poly(1-vinyl-3-ethylimidazolium tetrafluoroborate-co-acrylic acid/ oxidized carbon nitride) (P/P/O) by in situ radical copolymerization with oxygenated graphite carbon nitride (OCN). Specifically, the molecular structure, optical properties, photocatalytic removal of organic pollutants and photocatalytic bacterial inhibition were investigated for different P/P/O ratios. The results showed that P/P/O exhibited excellent light absorption and a high electron-hole separation rate. In addition, it also showed superior photocatalytic removal of MB ability with great cycle stability. Considering the effects of AA and OCN contents on the inhibition performance, P/P/O-2 exhibited the optimal bacteriostatic effect. It can effectively inhibit the growth of <em>E. coli</em> and <em>S. aureus</em> under visible light excitation, which showed the excellent synergistic inhibition performance. The diameters of the inhibition zone of P/P/O-2 on <em>E. coli</em> and <em>S. aureus</em> reached 21.49 mm and 22.36 mm, respectively. Meanwhile, the inhibition rate of P/P/O-2 on <em>E. coli</em> and <em>S. aureus</em> in 24 h reached 98.57 % and 98.59 %, respectively. Simultaneously, the minimum inhibitory concentration (MIC) for <em>E. coli</em> and <em>S. aureus</em> was 0.0469 mg/mL, at the same time, the inhibitory activity of P/P/O was concentration-dependent and broad-spectrum. Therefore, P/P/O with enhanced photocatalytic performance demonstrated its application potential in the field of photocatalytic bacteriostatic or self-cleaning.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"466 ","pages":"Article 116367"},"PeriodicalIF":4.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of halogenation on the photophysics of salicylideneimine-boron compound: An unusual behaviour with bromination","authors":"Suman Bhowmik ,&nbsp;Dipankar Mondal ,&nbsp;Kiran Arora ,&nbsp;Prakash P. Neelakandan ,&nbsp;Pratik Sen","doi":"10.1016/j.jphotochem.2025.116361","DOIUrl":"10.1016/j.jphotochem.2025.116361","url":null,"abstract":"<div><div>Understanding and controlling intersystem crossing (ISC) is crucial to generate triplet states, which have diverse applications across various fields. A commonly employed strategy to enhance ISC involves the incorporation of heavy atoms within the molecule. However, the introduction of heavy atoms, such as halogens, not only influences the ISC process but also alters the overall photophysical properties of the molecule. In this study, we investigated the photophysics of an organoboron compound (SB) with a donor–acceptor–BF₂ (D–A–BF₂) framework, and explored how halogenation modulates its excited-state dynamics. While organoboron compounds are generally known for their strong luminescence, our parent SB compound exhibited remarkably low fluorescence quantum yield and lifetime. Halogenation with heavy atoms, such as bromine and iodine, was expected to further quench fluorescence, as observed in the iodo derivative of SB (5ISB). Surprisingly, the bromo derivative (5BrSB) shows the opposite effect, with enhanced fluorescence quantum yield and lifetime. Our study suggests that the low fluorescence in the parent SB compound is probably due to the presence of a conical intersection (CI) between the S₁ and S₀ states, which facilitates the rapid non-radiative decay from the S₁ state. The introduction of heavy atoms seems to hinder the structural relaxation process, limiting the molecule’s ability to achieve the geometry required to form the CI. Additionally, the heavy atom effect in 5BrSB is insufficient to substantially enhance spin–orbit coupling (SOC). As a result, an increased fluorescence observed in the bromo-substituted compound.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"466 ","pages":"Article 116361"},"PeriodicalIF":4.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dipoles affect conformational equilibrium","authors":"Eli M. Espinoza ,&nbsp;J. Omar O’Mari ,&nbsp;James B. Derr ,&nbsp;Mimi Karen Billones ,&nbsp;John A. Clark ,&nbsp;Maryann Morales ,&nbsp;Tomasz Szreder ,&nbsp;Bing Xia ,&nbsp;Javier Ceballos ,&nbsp;Ctirad Červinka ,&nbsp;Valentine I. Vullev","doi":"10.1016/j.jphotochem.2025.116362","DOIUrl":"10.1016/j.jphotochem.2025.116362","url":null,"abstract":"<div><div>Electric dipoles are ubiquitous. They affect charge transfer, self-assembly, materials performance, and enzymatic activity. Herein, we demonstrate dipole effects on molecular geometry. An aromatic amide, 5-<em>N</em>-amide derivative of anthranilamide (Aaa), assumes two stable conformations with drastically different dipole moments. In non-polar solvents, Aaa exists predominantly as the conformer with the smaller dipole as nuclear Overhauser effect (NOE) and density-functional theory (DFT) analysis reveal. Increasing medium polarity drives the emergence of the other structure with the larger dipole. Splitting of the NMR signals at low temperature is consistent with capturing the two Aaa conformers upon its aggregation. Analysis employing density-functional theory quantifies the dynamics of the equilibrium between the two conformations and how solvent polarity affects it. This synergy between molecular electric dipoles and medium polarity reveals a paradigm for conformational switching.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116362"},"PeriodicalIF":4.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing photodynamic therapy: Talaporfin-encapsulated silica nanoparticles for red blood cell disruption in cancer treatment","authors":"Ghaseb N. Makhadmeh ,&nbsp;Tariq AlZoubi ,&nbsp;Samer H. Zyoud ,&nbsp;Mahmoud Al-Gharram ,&nbsp;M.H.A. Mhareb ,&nbsp;Osama Abu Noqta ,&nbsp;Abdulsalam Abuelsamen","doi":"10.1016/j.jphotochem.2025.116356","DOIUrl":"10.1016/j.jphotochem.2025.116356","url":null,"abstract":"<div><div>Photodynamic therapy (PDT) is a highly effective cancer treatment that combines a photosensitizer (PS), and light for targeted cancer cell destruction in present of oxygen. However, the delivery of photosensitizers remains a challenge due to degradation risks and systemic toxicity. This study investigates the encapsulation of Talaporfin, a second-generation chlorin-based photosensitizer, within silica nanoparticles (SiNPs) to enhance PDT efficacy and safety. The research focuses on using red blood cells (RBCs) as a model system, highlighting their critical role in the tumor microenvironment. By targeting and destroying RBCs in proximity to tumors, PDT can disrupt the oxygen supply, indirectly leading to cancer cell death. Talaporfin-encapsulated SiNPs (T-SiNPs) were synthesized via a microemulsion method and characterized for size, morphology, and stability. The photodynamic effects of encapsulated versus naked Talaporfin were evaluated under varying concentrations and light exposure times. Results revealed that T-SiNPs achieved higher therapeutic efficacy, requiring lower concentrations and shorter exposure durations. This enhanced performance is attributed to improved light absorption and ROS production due to reduced aggregation of Talaporfin within SiNPs. Additionally, mathematical equations were developed to correlate the concentrations of encapsulated and naked Talaporfin with the 50% mortality rate (t₅₀) of RBCs. These equations provide a predictive framework for optimizing PDT protocols, enabling the determination of optimal drug concentrations and exposure times without extensive experimental trials. This study underscores the potential of silica nanoparticles as efficient carriers for photosensitizers, enhancing PDT outcomes by targeting both RBCs and cancer cells. The findings pave the way for innovative cancer therapies that leverage nanotechnology to achieve precise, effective, and safer treatments. Future applications of this approach may extend to broader therapeutic areas, further revolutionizing modern medicine.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116356"},"PeriodicalIF":4.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visible light photocatalytic selective oxidation of alcohols by rhodium@graphitic carbon nitride nanosheets as effective catalyst","authors":"Razieh Nejat ,&nbsp;Somaye Shahraki ,&nbsp;Parisa Shahriary","doi":"10.1016/j.jphotochem.2025.116360","DOIUrl":"10.1016/j.jphotochem.2025.116360","url":null,"abstract":"<div><div>In this work, we present the development of a novel photocatalyst system based on graphitic carbon nitride (g-C₃N₄) nanosheets decorated with Rhodium, denoted as Rh/g-C₃N₄, in Selective Oxidation of alcohols. The graphitic carbon nitride nanosheets were synthesized from OAT (Oxi Amino Triazine) as a waste material which is a by-product of the melamine unit of North Khorasan Petrochemical Company. The rhodium precursors employed were 5-methyl-5-(2-pyridyl)-2,4-imidazolidenedione and K₃[RhCl₆], which formed Rh metallic nanoparticles on the surface of the g-C₃N₄ support. The Rh particles anchored on g-C₃N₄ are instrumental in enhancing the efficient separation of photogenerated charges and exhibit considerable absorption under the visible-light. More notably, Rh/g-C₃N₄ demonstrates performance that exceeds that of both bare g-C₃N₄ and thecomplex. This new class of heterogeneous photocatalysts demonstrates exceptional activity and selectivity in the oxidation of alcohols under visible light irradiation. A conversion rate of 88 % was achieved using the Rh/g-C₃N₄ photocatalyst after 120 min of visible light irradiation. These features make the developed g-C₃N₄-supported Rh particles a promising candidate for practical applications in organic synthesis. The produced catalyst was characterized using a variety of techniques.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116360"},"PeriodicalIF":4.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-step synthesis of multicolor room temperature phosphorescent carbon dots for information encryption applications","authors":"Xuechun Xu ,&nbsp;Jinyue Liang ,&nbsp;Xujing Zheng ,&nbsp;Jie Shen ,&nbsp;Liangliang Lin ,&nbsp;Xiting Chen ,&nbsp;Yiming Zhao ,&nbsp;Wenfei Xue","doi":"10.1016/j.jphotochem.2025.116320","DOIUrl":"10.1016/j.jphotochem.2025.116320","url":null,"abstract":"<div><div>Room temperature phosphorescent carbon dots (RTP CDs) are widely applied in fields due to their unique phosphorescent properties. However, some current synthesis methods for RTP CDs are relatively complex and the RTP CDs often have poor phosphorescence stability. Here, the multicolor RTP CDs with green and yellow was proposed in a one-step method. Using biuret as the precursor, the introduction of different matrices (boric acid and inorganic salts) makes the RTP CDs emitting different phosphorescence colors. Both of the RTP CDs exhibit excellent resistance to both prolonged UV exposure and ambient air. Structural analysis reveals that the hydrogen bonds formed between the RTP CDs and the matrix exhibits good oxygen-blocking and water-resistance properties, resulting in good phosphorescence stability. The carbonyl and nitrogen heterocycles on the biuret are the main contributors to the phosphorescent emission of the CDs. Moreover, the halogen bonds and covalent bonds between the CDs and the matrix also influence the phosphorescence emission wavelength. Additionally, the RTP CDs were successfully applied in information encryption. This study provides an effective strategy for preparing RTP CDs with improved phosphorescence stability.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116320"},"PeriodicalIF":4.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and validation of a green spectrofluorimetric method for brivaracetam determination using N-doped graphene quantum dots: Mechanistic insights and bioanalytical applications","authors":"Reem M. Alnemari ,&nbsp;Maram H. Abduljabbar ,&nbsp;Yusuf S. Althobaiti ,&nbsp;Sameer Alshehri ,&nbsp;Farooq M. Almutairi ,&nbsp;Humood Al Shmrany ,&nbsp;Eid Semer Alatwi ,&nbsp;Ahmed Serag ,&nbsp;Atiah H. Almalki","doi":"10.1016/j.jphotochem.2025.116357","DOIUrl":"10.1016/j.jphotochem.2025.116357","url":null,"abstract":"<div><div>Brivaracetam is an important antiepileptic drug, and its sensitive and selective determination in biological matrices is crucial for therapeutic drug monitoring and pharmacokinetic studies. However, the currently available analytical methods suffer from limitations such as low sensitivity, high environmental impact, and complex sample preparation. In this work, a highly sensitive and selective spectrofluorimetric method was developed for the determination of brivaracetam in human plasma and pharmaceutical formulations. The method is based on the interaction between brivaracetam and N-doped graphene quantum dots (GQDs) leading to fluorescence quenching. The quenching mechanism was investigated using density functional theory calculations, Stern-Volmer analysis and thermodynamic studies. A static quenching process was observed indicating complex formation between the analyte and nanomaterial. Different factors affecting the quenching efficiency were carefully optimized such as pH, GQDs concentration, and incubation time. The proposed method was validated according to the ICH M10 guidelines and showed excellent linearity in the concentration range of 0.1–2.5 μg/mL with a limit of detection of 0.033 μg/mL. Furthermore, the method displayed good precision and accuracy, and selectivity in the presence of common plasma/formulation excipients. Hence, the developed method was successfully applied for the determination of brivaracetam in pharmaceutical formulations as well as pharmacokinetic monitoring in human plasma samples. The “greenness”, “blueness” and “whiteness” of the proposed method was also evaluated using the AGREE, BAGI and RGB12 metrics, respectively, confirming its eco-friendly, high practicability and sustainable nature transcending the reported conventional analytical techniques, posing the developed method as a promising analytical tool for brivaracetam determination.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116357"},"PeriodicalIF":4.1,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uptake of luminescent colloidal Ag–In–S nanoprobes by BC cells differing in metastasis propensity","authors":"E. Kontareva ,&nbsp;E. Pershikova ,&nbsp;A. Sizikov ,&nbsp;A. Mutali ,&nbsp;M. Pustovalova ,&nbsp;S. Leonov ,&nbsp;Y. Merkher","doi":"10.1016/j.jphotochem.2025.116359","DOIUrl":"10.1016/j.jphotochem.2025.116359","url":null,"abstract":"<div><div>This study investigates the metastasis-dependent cellular uptake of luminescent colloidal silver–indium–sulfur (Ag–In–S) nanoprobes in breast cancer (BC) cells. We developed water-soluble fluorescent semiconductor nanocrystals (quantum dots, QDs) that exhibit exceptional brightness, remarkable photostability, and impressive resistance to photobleaching. The Ag–In–S quantum dots, coated with either mercaptopropionic acid (MPA–Ag–In–S) or branched polyethyleneimine (BPEI–Ag–In–S), demonstrate a broad emission spectrum ranging from deep red to bluish green, achieving photoluminescence quantum yields of up to 47 %. The absorption spectra revealed peaks ranging from 290 nm to 440 nm, with a persistent peak at 555 nm observed across all quantum dots. The size of MPA–Ag–In–S nanoparticles ranged from 2 to 5 nm, while BPEI-–Ag–In–S nanoparticles ranged from 150 to 200 nm.</div><div>We employed a scanning microplate fluorometer to accurately measure the cellular uptake of QDs, normalizing the fluorescence data based on DNA content quantified using Hoechst 33,342 dye. Our findings revealed that cells exhibiting high MP internalized significantly more QDs compared to those with low MP, showing an increase of 1.5–1.7 times. Toxicity assays demonstrated that MPA–Ag–In–S QDs exhibited no toxic effects on both high and low MP cells. In contrast, BPEI–Ag–In–S QDs caused substantial cell death within just one hour of exposure.</div><div>Comparative analysis with commercially available nanoparticles highlighted the superior concentration and fluorescence properties of our synthesized QDs. These results indicate that Ag–In–S nanoprobes may be a powerful tool for distinguishing the metastatic potential of cancer cells, presenting a promising avenue for enhanced targeted cancer diagnostics and treatment.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116359"},"PeriodicalIF":4.1,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic behavior of the fluorescence features of Eosin Y in PVA-Borax hydrogel","authors":"Soghra Mohammadzadeh,&nbsp;Ali Bavali,&nbsp;Ali Rahmatpanahi,&nbsp;Farzad Mokhtari","doi":"10.1016/j.jphotochem.2025.116358","DOIUrl":"10.1016/j.jphotochem.2025.116358","url":null,"abstract":"<div><div>In most biophotonics applications of dye-gel blends, the gel is illuminated by a light source (usually a laser or LED) for a considerable period of time. Therefore, it is crucial to examine the temporal behavior of the corresponding luminescence features. In the present report, a photosensitive hydrogel was synthesized using Eosin Yellow (EY) as the dye, Polyvinyl Alcohol as the polymer and Borax as the cross-linking agent (EY-PVA-Borax hydrogel). Dynamic behavior of the corresponding fluorescence emission due to excitation of by a diode laser at λ = 445 nm (which is the isosbestic point of the EY absorption spectrum during the photodegradation process) were studied parametrically and evaluated using difference spectra analysis (DSA). In general, the wavelength at the fluorescence peak underwent hypsochromic shift with irradiation time, while the intensity increased in the first 9.0 s and then decreased gradually. Hydrogen bonding between the hydroxyl group of PVA and the carboxyl group of EY, aggregation of the EY molecules and debromination of the EY monomers under light irradiation were considered to explain the dynamic behavior of the fluorescence emission from the gel. Considering the use of hydrogels as photo-convertors, the influence of gel layer thickness on the fluorescence spectrum was examined. The results obtained are of particular importance for the design of fluorescence-based biosensors and also in the field of fluorescence biomodulation.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":"465 ","pages":"Article 116358"},"PeriodicalIF":4.1,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}