Visible Dye Research Articles

Nanolabels Prepared by the Entrapment or Self-Assembly of Signaling Molecules for Colorimetric and Fluorescent Immunoassays

Nanomaterials have attracted significant attention as signal reporters for immunoassays. They can directly generate detectable signals or release a large number of signaling elements for readout. Among various nanolabels, nanomaterials composed of multiple signaling molecules have shown great potential in immunoassays. Generally, signaling molecules can be entrapped in nanocontainers or self-assemble into nanostructures for signal amplification. In this review, we summarize the advances of signaling molecules-entrapped or assembled nanomaterials for colorimetric and fluorescence immunoassays. The nanocontainers cover liposomes, polymers, mesoporous silica, metal–organic frameworks (MOFs), various nanosheets, nanoflowers or nanocages, etc. Signaling molecules mainly refer to visible and/or fluorescent organic dyes. The design and application of immunoassays are emphasized from the perspective of nanocontainers, analytes, and analytical performances. In addition, the future challenges and research trends for the preparation of signaling molecules-entrapped or assembled nanolabels are briefly discussed.

Hyperspectral Image Transects during Transient Events in Rivers (HITTER): Framework Development and Application to a Tracer Experiment on the Missouri River, USA

Rivers convey a broad range of materials, such as sediment, nutrients, and contaminants. Much of this transport can occur during or immediately after an episodic, pulsed event like a flood or an oil spill. Understanding the flow processes that influence the motion of these substances is important for managing water resources and conserving aquatic ecosystems. This study introduces a new remote sensing framework for characterizing dynamic phenomena at the scale of a channel cross-section: Hyperspectral Image Transects during Transient Events in Rivers (HITTER). We present a workflow that uses repeated hyperspectral scan lines acquired from a hovering uncrewed aircraft system (UAS) to quantify how a water attribute of interest varies laterally across the river and evolves over time. Data from a tracer experiment on the Missouri River are used to illustrate the components of the end-to-end processing chain we used to quantify the passage of a visible dye. The framework is intended to be flexible and could be applied in a number of different contexts. The results of this initial proof-of-concept investigation suggest that HITTER could potentially provide insight regarding the dispersion of a range of materials in rivers, which would facilitate ecological and geomorphic studies and help inform management.

Stability and photophysical study of bright day light fluorescent material and its fabrication in laser patterning and LED application

Developing aggregation-induced emission (AIE) active highly visible fluorescent dyes is of great importance because of its numerous applications. We have successfully developed and synthesized two novel napthalimide based molecules PU1 and PU2, that exhibit bright greenish yellow in day light and vivid green emission when exposed to UV light. Compounds PU1 and PU2 exhibit variable emission behavior at different solvent polarities. Upon raising the solvent polarity from ether to DMF, emission maxima of PU1 and PU2 underwent a bathochromic shift. Additionally, compounds PU1 and PU2 show signs of AIE, which cause a restriction in intramolecular mobility. A distinct self-assembled structure was generated at 30 % aqueous DMF solution following aggregation, as demonstrated by experiments using dynamic light scattering and field emission scanning electron microscopy. Compounds PU1 and PU2 have been blended with poly(urethane) to develop a polymeric film. Tensile strain studies, and TGA, DSC analyses were used to examine the thermal/mechanical stability of PU films. The photostability of PU1 and PU2 in both solution and polymeric film was examined using a 5-h UV-beam irradiation. Furthermore, in the presence of trifluoroacetic acid, the blended polymeric film and 365 nm LED light coated material exhibits distinct colorimetric and fluorimetric transformations. Finally, laser-induced periodic surface structure (LIPSS) pattern processing on PU1 coated substrates can be extended for optical applications.

Incorporation of pre- and intra-operative sentinel lymph node mapping techniques in dogs with apocrine gland anal sac adenocarcinoma

The high incidence of nodal metastasis, variable lymphatic drainage patterns, and prognostic significance of nodal metastasis in dogs with apocrine gland anal sac adenocarcinoma (AGASACA) highlight the need for development of standardized techniques for lymph node staging in canine AGASACA. The aim of this study was to develop and describe the utility of pre- and intra-operative sentinel lymph node (SLN) mapping techniques for subsequent nodal extirpation and histologic assessment in dogs with AGASACA. A prospective clinical trial was performed as a pilot study. Eight client-owned dogs with unilateral AGASACA were enrolled. Preoperative contrast-enhanced ultrasound (CEUS) via transrectal ultrasound (TRUS) and CT-lymphography (CTL) was followed by intraoperative SLN mapping within 7 days utilizing a visible dye (methylene blue [MB]) and a near-infrared (NIR) fluorescent dye (indocyanine green [ICG]) with subsequent nodal extirpation and routine anal sacculectomy. In all dogs, preoperative CTL and intraoperative SLN mapping identified at least one SLN. Pre- and intra-operative findings differed in 4/8 dogs. Preoperative CEUS identified a SLN in 7/8 dogs, but the exact location of the SLN was indeterminate. Extirpated lymph nodes were metastatic in 2/8 dogs. Preoperative CTL and intraoperative MB and ICG were an effective combination of SLN mapping techniques in dogs with AGASACA. These techniques each provided unique advantages. Combined, they identified and guided extirpation of early metastatic lymph nodes. Large-scale, prospective studies utilizing the techniques described are needed to accurately determine the incidence and significance of early/occult nodal metastasis in canine AGASACA.

Green engineered Mo-CeO2@C nanocomposites for visible light-assisted dye decomposition and microbial apoptosis

The profound contamination of reservoirs triggered by industrial dyes and the growing phenomenon of antibiotic-resistant bacteria present substantial risks to both the environment and human health. Conventional approaches to water treatment and microbiological disinfection can frequently become ineffective, expensive, and detrimental to the environment, and this issue underscores the need for novel materials that possess refined photocatalytic and antibacterial characteristics that thrive efficiently in a setting of visible light. An innovative nanostructured nanocomposite, Mo-CeO2@C, was synthesized using a green chemistry method coupled with Mo-CeO2 nanoparticles and pristine CeO2. The impact of Ce, Mo, and carbon-based nanocomposites has been validated by leveraging XRD, FTIR, UV–vis spectra, and FE-SEM/EDX. The sunlight-mediated photodegradation performance of carbon-based nanocomposite exhibited a superior photodegradation efficiency of 99.5 %, higher than others. The photocatalytic activity of M.B. dye concentration, catalyst dosage, scavenger test, and recyclability were also conducted, which confirm the optimal catalyst loading of 20 mg, dye concentration 40 ppm, and pH 8 with reusability up to sixth cycles. The carbon-coated doped nanocomposite displays superior antibacterial efficacy against gram-positive S. aureus, gram-negative E. coli, and P. vulgaris bacteria in comparison to CeO2 and Mo-doped CeO2. This may be attributed to the combined effects of the generation of reactive oxygen species (R.O.S.) and the intrinsic characteristics of the dopant and carbon matrix. The results of our research emphasize the potential of carbon-based nanoparticles as versatile agents in the realms of environmental rehabilitation and biomedical research. These nanoparticles provide a method to achieve more efficient and resilient solutions in these areas.

Thermally synthesized hematite (α-Fe2O3) nanoparticles as efficient photocatalyst for visible light dye degradation.

In recent years, water pollution has become a pressing global issue because of the continuous release of organic dyes from various industries. Therefore, finding an easy way to remove these harmful dyes from water has drawn the attention of researchers. This study investigates the removal of toxic Rose Bengal (RB) dye using hematite nanoparticles as a visible light photocatalyst without any additive. It is observed that by controlling particle size, quantity of the nanoparticles and reaction temperature, the dye degradation can be improved up to 95.33% with a half-life of 26 min. To understand photodegradation kinetic behavior, the Langmuir-Hinshelwood kinetic equation can be employed. The scavenger test indicated that the OH* radicals majorly led to the photodegradation process. The reaction rate values strongly depended on the size, quantity of the nanoparticles and reaction temperature. Controlling the optimizing condition, faster reaction rate (k = 0.027 min-1) can be achieved as compared to earlier reports. It is also noted that the change in the degradation efficiency of the reused catalyst is negligible when compared to the fresh one. Here, the dye degradation mechanism is discussed. Overall, this study reveals that hematite nanoparticles can be used as efficient photocatalyst for dye degradation applications by optimizing the controlling factors. These observations provide novel perspectives on the development of effective and sustainable photocatalytic technologies for pollution control and water treatment applications.

Evaluation of the benefit of indocyanine green as an educational and practical tool for ureteral identification in laparoscopic pelvic surgery: a cross-sectional study

Background Indocyanine green (ICG) is a visible near-infrared fluorescent dye. Several studies have reported its benefit in identifying important anatomical structures, tissue vascularization, and sentinel lymph nodes in the case of tumors. Studies have shown that ICG is critical and safe in gynecologic surgeries. However, research on how ICG dye can help surgeons in laparoscopic surgeries correctly identify the course of the ureter has yet to be further investigated. Method This cross-sectional study enrolled 62 gynecology attending and resident surgeons who were asked to identify the course of the ureter on images of laparoscopic surgeries. The results were then compared with images in which ICG dye highlighted the course of the ureter. The purpose of this study was to detect the ability of surgical assistants and residents to adequately identify the course of the ureter in laparoscopic pelvic surgeries. Results No statistically significant differences were found in terms of year of residency, years of experience, number of laparoscopic procedures attended, and correct identification of ureter course. ICG proved useful in identifying the correct ureteral trajectory. Conclusions ICG can be a valuable tool to improve the correct identification of ureters and improve surgical outcomes.

Chemical spray deposited SnO2:MoO3 composite thin films for visible light photocatalytic dye degradation application

Chemical spray deposited SnO2:MoO3 composite thin films for visible light photocatalytic dye degradation application

Miniature wireless LED-device for photodynamic-induced cell pyroptosis

The inability of visible light to penetrate far through biological tissue limits its use for phototherapy and photodiagnosis of deep-tissue sites of disease. This is unfortunate because many visible dyes are excellent photosensitizers and photocatalysts that can induce a wide range of photochemical processes, including photogeneration of reactive oxygen species. One potential solution is to bring the light source closer to the site of disease by using a miniature implantable LED. With this goal in mind, we fabricated a wireless LED-based device (volume of 23 mm3) that is powered by RF energy and emits light with a wavelength of 573 nm. It has the capacity to excite the green absorbing dye Rose Bengal, which is an efficient type II photosensitizer. The wireless transfer of RF power is effective even when the device is buried in chicken breast and located 6 cm from the transmitting antenna. The combination of a wireless device as light source and Rose Bengal as photosensitizer was found to induce cell death of cultured HT-29 human colorectal adenocarcinoma cells. Time-dependent generation of protruding bubbles was observed in the photoactivated cells suggesting cell death by light-induced pyroptosis and supporting evidence was gained by cell staining with the fluorescence probes Annexin-V FITC and Propidium Iodide. The results reveal a future path towards a wireless implanted LED-based device that can trigger photodynamic immunogenic cell death in deep-seated cancerous tissue.

Retraction Note: Visible light-enhanced photocatalytic dye degradation and hydrogen evolution performance of BiVO4 thin films prepared at various annealing temperatures

Retraction Note: Visible light-enhanced photocatalytic dye degradation and hydrogen evolution performance of BiVO4 thin films prepared at various annealing temperatures

α-Fe2O3/g-C3N4 nanocomposite with type II heterojunction for methylene blue photodegradation

Recently, the widespread use of industrial dyes, such as methylene blue, is raising concerns about organic pollutants. These compounds can persist in the environment, contaminating water sources and harming aquatic ecosystems. The aim of the current study is to develop a nano-composite by mechanically grinding graphitic carbon nitride g-C3N4 and hematite α-Fe2O3, which cloud potentially be used for degradation of Methylene bleu organic pollutant. The obtained heterojunction nanocomposite, named 1 % α-Fe2O3/g-C3N4 (Fe/gCN), was characterized using XRD, ATR-FTIR, and SEM-EDS analysis. The industrial methylene blue (MB) dye was used to assess the visible light photodegradation efficiency of the Fe/gCN nanocomposite. The findings revealed a notable improvement in the photocatalytic degradation performance of the Fe/gCN nanocomposite. Furthermore, the band gap of Fe/gCN nanocomposite was narrowed from 2,78 to 2,54 eV Comparing to gCN alone. Compared with pure α-Fe2O3 and gCN, the Fe/gCN nanoparticles showed enhanced visible-light-induced photocatalytic performance which degrade efficiently 99,64 % of MB dye. The optimal conditions were determined as: pH =10,3, photocatalyst mass of 0,6 g/l and contact time t = 120 min for the Fe/gCN composite. •OH and •O2− radicals were identified as the dominant active species responsible for MB degradation and played the most crucial roles, while h+ and e− radicals were less contributing in MB photocatalytic elimination. Kinetic studies indicated that the MB photocatalytic decomposition of by Fe/gCN followed a pseudo second-order (PSO) model. These findings underscore the great potential of Fe/gCN nanocomposite for the visible light-induced MB dye photodecomposition.

Effect of Position of Donor Units and Alkyl Groups on Dye-Sensitized Solar Cell Device Performance: Indoline-Aniline Donor-Based Visible Light Active Unsymmetrical Squaraine Dyes.

Indoline (In) and aniline (An) donor-based visible light active unsymmetrical squaraine (SQ) dyes were synthesized for dye-sensitized solar cells (DSSCs), where the position of An and In units was changed with respect to the anchoring group (carboxylic acid) to have In-SQ-An-CO2H and An-SQ-In-CO2H sensitizers, AS1-AS5. Linear or branched alkyl groups were functionalized with the N atom of either In or An units to control the aggregation of the dyes on TiO2. AS1-AS5 exhibit an isomeric π-framework where the squaric acid unit is placed in the middle, where AS2 and AS5 dyes possess the anchoring group connected with the An donor, and AS1, AS3, and AS4 dyes having the anchoring group connected with the In donor. Hence, the conjugation between the middle squaric acid acceptor unit and the anchoring -CO2H group is short for AS2, AS5, and AK2 and longer for AS1, AS3, and AS4 dyes. AS dyes showed absorption between 501 and 535 nm with extinction coefficients of 1.46-1.61 × 105 M-1 cm-1. Further, the isomeric π-framework of An-SQ-In-CO2H and In-SQ-An-CO2H exhibited by means of changing the position of In and An units a bathochromic shift in the absorption properties of AS2 and AS5 compared to the AS1, AS3, and AS4 dyes. The DSSC device fabricated with the dyes contains short acceptor-anchoring group distance (AS2 and AS5) showed high photovoltaic performances compared to the dyes having longer distance (AS1, AS3, and AS4) with the iodolyte (I-/I3-) electrolyte. DSSC device efficiencies of 5.49, 6.34, 6.16, and 5.57% have been achieved for AS1, AS2, AS3, and AS4 dyes, respectively; without chenodeoxycholic acid (CDCA), small changes have been observed in the device performance of the AS dyes with CDCA. Significant changes have been noted in the DSSC parameters (open-circuit voltage VOC, short-circuit current JSC, fill factor ff, and efficiency η) for the AS5 dye while sensitized with CDCA and showed highest DSSC efficiency of 8.01% in the AS dye series. This study revealed the potential of shorter SQ acceptor-anchoring group distance over the longer one and the importance of alkyl groups on the overall DSSC device performance for the unsymmetrical squaraine dyes.

Abstract 76: Correlated multi-scale 3D optical microscopy of tumor tissues

Abstract Three-dimensional (3D) optical microscopy in combination with advanced tissue clearing methods permits the interrogation of intact large-sized tumor tissues. There are many optical microscopy methods (e.g. light-sheet and confocal microscopy) offering 3D tumor images at varying levels of spatial resolution (e.g. organ, tissue, cell, and molecule level). However, it is a challenge to correlatively integrate various resolution 3D images obtained by different optical microscopy of tumor tissue. In this project, we developed a correlated multi-scale 3D optical microscopy method that enables the acquisition of macroscopic to microscopic spatial information from a single tumor tissue in 3D. Firstly, we used light sheet microscopy to image a whole large-sized, cleared tumor tissue and analyzed the results to identify regions of interests (ROIs). After defining ROIs in the 3D whole tumor image, we added a UV-activatable visible dye, spiropyran, in the agarose gel surrounding the cleared tumor and exposed the sample to a UV light sheet horizontally at the height (z-axis) of the tumor where the ROIs present. The activated dye showed ‘purple’ colored lines in the agarose gel and we physically marked the gel along the visible colored lines. We further sectioned the tumor at the ROI positions using a vibratome after reversing tissue clearing process. After immunofluorescence staining and aqueous-based tissue clearing, confocal microscopy allowed the localization of various cell types in the ROIs of tumor macrosections. To validate the method for multi-scale evaluation of cancer immunotherapy, we tested it with control and DMXAA-treated mouse mammary tumor tissues. We successfully acquired the 3D images of whole tumors by capturing autofluorescence signals with a 633 nm excitation laser and its matched emission filter. Based on the autofluorescence tumor images, we defined two ROIs for each control and treated tumor and performed optical marking and physical sectioning of the tumors as described above. Next, we stained the macrosections (400 µm thick) with DAPI, CK8-DL488, CD45-DL550, and ER-TR7-DL680 to visualize cancer, immune, and stromal cells in the ROIs at cellular resolution. We quantitatively analyzed the correlated multi-scale 3D image data for assessment of the effects of DMXAA treatment on the tumor microenvironment including eradiation of cancer cells, immune infiltration, and remodeling of tumor stroma. In summary, this new microscopy method will provide comprehensive spatial information of tumor tissues and benefit a broad cancer research field such as the discovery of new tumor biomarkers and the development of effective cancer therapies. Citation Format: Jingtian Zheng, Steve Seung-Young Lee. Correlated multi-scale 3D optical microscopy of tumor tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 76.

Sensitive and Specific Loop-Mediated Isothermal Amplification Assays for Detection of Salmonella, CTX-M-1 Group Genes, mph(A), and ermB in Stool and Blood Samples Based on Orange to Green Visible Dye.

Salmonella is a globally prevalent foodborne bacterium, and ceftriaxone and azithromycin have been regarded as drugs of choice for treating Salmonella infections, particularly in children. With the growing incidence of ceftriaxone and azithromycin resistance in Salmonella, there is an urgent requirement for a rapid and dependable gene testing approach to enhance the efficacy of treating Salmonella infections. Utilizing the orange to green visible dye approach, this study developed loop-mediated isothermal amplification (LAMP) assays for the sensitive and specific detection of Salmonella, ceftriaxone and azithromycin resistance genes (including CTX-M-1 group, mph(A), and ermB genes) in stool and blood samples. The specificity and sensitivity of primers during the LAMP assays for detection of Salmonella, CTX-M-1 group, mph(A), and ermB genes were determined in this study. The detection threshold for Salmonella was found to be 1.5 × 103 colony-forming units (CFU)/mL, while it was 1.5 × 102 CFU/mL for CTX-M-1 group genes (including blaCTX-M-3, blaCTX-M-15, and blaCTX-M-55), 1.5 × 102 CFU/mL for mph(A), and 1.5 × 102 CFU/mL for ermB, showing 10-103-fold, 103-fold, and 105-fold increased sensitivity compared with the polymerase chain reaction assay, respectively. Results indicated that the LAMP primers designed for Salmonella, CTX-M-1 group, mph(A), and ermB genes possess high specificity (100%) and sensitivity (over 94%). This novel approach advocates its application in detecting Salmonella, CTX-M-1 group, mph(A), and ermB genes.

Abstract 3771: 3D correlated multi-scale cellular and molecular architecture of solid tumors

Abstract A solid tumor presents heterogeneous 3D structures at tissue, cell, and molecule levels. To develop advanced cancer diagnostics and therapies, it is important to understand in-depth cellular and molecular architecture of a tumor at multiple scales. Here we introduce novel optical microscopy methodologies for in-depth 3D spatial analysis of tumor tissues: 1) LED photobleaching-mediated 3D multiplex immunofluorescence (IF) microscopy, 2) Correlated 3D multi-resolution optical microscopy, and 3) 3D tissue region-based cell type-selective multi-omics. We built a high-power LED light irradiator with a broad emission spectrum (490-700 nm) that bleaches a broad wavelength of fluorescence signals simultaneously throughout an optically cleared, 400 µm-thick tumor tissue. Cyclic workflow involving IF staining, optical tissue clearing, 3D confocal microscopy, and LED photobleaching enables visualization of multiple cell types in the same whole 400 µm-thick tumor tissue after computational 3D image registration. The constructed multiplex image offers comprehensive 3D cellular landscape of a tumor. We also developed a method for tracking regions of interest (ROIs) in the middle of a large tumor tissue using a UV-activated visible dye in light sheet microscopy. Light sheet microscopy allows imaging an optically cleared large-sized tumor tissue at a low spatial, tissue resolution. To mark the ROI positions on a tumor, the dye is infused into agarose gel surrounding the tumor tissue and be activated and present purple-colored lines where are exposed to UV light sheets in light sheet microscopy. The tumor tissue was physically sectioned at the marked ROI positions using a vibratome after reversing tissue clearing process. Sequential IF staining and high-resolution confocal microscopy permit for visualizing detailed cellular compositions of the ROIs in the tumor. The tissue and cellular-resolution 3D images from light sheet and confocal microscopy are correlatively integrated to display ‘Google Earth’-like multi-scale view of a tumor tissue. To further analyze the ROIs of a tumor at molecular level, we have developed optical microscope-mediated fluorescence lithography methods that allow fluorescently labeling of a selected cell type in ROIs of an optically cleared 3D tumor tissue. After wash free from clearing solution and dissociation of the tumor into cells, fluorescence-marked, intact cells from the ROIs are collected through flow cell sorting. Proteins and mRNAs are extracted from the collected cells and sent to LC-MS/MS analysis and RNA sequencing. The spatial multi-omics method provides in-depth molecular information of selected cells in the ROIs of a tumor. We believe all these 3D microscopy methods will provide powerful spatial analysis tools for better understanding cellular and molecular architecture of solid tumors. Citation Format: Steve Seung-Young Lee, Yi-Chien Wu, Jingtian Zheng, Elie Abi Khalil, Samuel Wang, Alexander Lippert, Joshua Plank. 3D correlated multi-scale cellular and molecular architecture of solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3771.

Visible light photocatalytic dye degradation, antimicrobial activities of green synthesized Ag/TiO2 nanoparticles

The co-precipitation approach was used in this study to synthesize Ag/TiO2 nanoparticles (NPs) using an extract of the flowers from C. pulcherrima. As a reducing agent and a stabilizer during the synthesis process, the flower extract performed a dual function. The surface plasmon resonance in the diffuse reflectance spectroscopy spectrum provided assurance that the Ag+, and Ti4+ ions were significantly reduced. The bandgap study of the Ag/TiO2 NPs revealed that they are suitable for optical and catalytic applications. The NPs were analyzed using X-ray diffraction (XRD) to assess their size and crystal structure. Through scanning and transmission electron microscopy (SEM and TEM), the shape and size changes of the Ag/TiO2 NPs were studied. Energy-dispersive X-ray spectroscopy (EDX) analysis was employed to investigate the elements' chemical composition in the produced NPs. A Fourier transform infrared spectroscopy (FTIR) study was carried out to identify functional groups that might be present in the plant extract and might be involved in the chemical reduction, stabilization, and bonding processes. The photocatalytic disintegration of the hazardous organic dye pollutant methylene blue was studied for 40 min while being exposed to visible light. The flower extract was used to create Ag/TiO2 NPs efficiency degradation rate of 94 %. Additionally, then NPs antimicrobial capacity was assessed, and it was discovered that they were most effective against the infections P. aeruginosa and E. coli.

Visible, Far-Red, and Near-Infrared Active Unsymmetrical Squaraine Dyes Based on Extended Conjugation within the Polymethine Framework for Dye-Sensitized Solar Cells

Visible, Far-Red, and Near-Infrared Active Unsymmetrical Squaraine Dyes Based on Extended Conjugation within the Polymethine Framework for Dye-Sensitized Solar Cells

Polyoxometalate-dependent Photocatalytic Activity of Radical-doped Perylenediimide-based Hybrid Materials.

Inorganic-organic hybrid materials are a kind of multiduty materials with high crystallinity and definite structures, built from functional inorganic and organic components with highly tunable photochemical properties. Perylenediimides (PDIs) are a kind of strong visible light-absorbing organic dyes with π-electron-deficient planes and photochemical properties depending on their micro-environment, which provides a platform for designing tunable and efficient hybrid photocatalytic materials. Herein, four radical-doped PDI-based crystalline hybrid materials, Cl4-PDI⋅SiW12O40 (1), Cl4-PDI⋅SiMo12O40 (2), Cl4-PDI⋅PW12O40 (3), and Cl4-PDI⋅PMo12O40 (4), were attained by slow diffusion of polyoxometalates (POMs) into acidified Cl4-PDI solutions. The obtained PDI-based crystalline hybrid materials not only exhibited prominent photochromism, but also possessed reactive organic radicals under ambient conditions. Furthermore, all hybrid materials could be easily photoreduced to their radical anions (Cl4-PDI⋅-), and then underwent a second photoexcitation to form energetic excited state radical anions (Cl4-PDI⋅-*). However, experiments and theoretical calculations demonstrated that the formed energetic Cl4-PDI⋅-* showed unusual POM-dependent photocatalytic efficiencies toward the oxidative coupling of amines and the iodoperfluoroalkylation of alkenes; higher photocatalytic efficiencies were found for hybrid materials 1 (anion: SiW12O40 4-) and 2 (anion: SiMo12O40 4-) compared to 3 (anion: PW12O40 3-) and 4 (anion: PMo12O40 3-). The photocatalytic efficiencies of these hybrid materials are mainly controlled by the energy differences between the SOMO-2 level of Cl4-PDI⋅-* and the LUMO level of the POMs. The structure-photocatalytic activity relationships established in present work provide new research directions to both the photocatalysis and hybrid material fields, and will promote the integration of these areas to explore new materials with interesting properties.

Novel MgO and Ag/MgO nanoparticles green-synthesis for antibacterial and photocatalytic applications: A kinetics-mechanism & recyclability

The present study identifies the novel nano production of MgO nanoparticles as well as the Ag decoration of MgO nanoparticles using Morinda tinctoria plant extract. Green compounds are used to reduce zero valent atoms and to decorate metal oxide surfaces. X-ray Diffractometer analysis (XRD) was used to examine the cubic structure of MgO (28 nm) and Ag/MgO (21 nm) nanoparticles. Fourier transform infrared spectroscopy (FTIR) analysis was used to determine the reactive functional groups, metal–oxygen bonding, and OH molecules. Ultra-Violet Diffuse Reflectance Spectroscopy (UV-DRS) analysis revealed the optical entity and their orbital electron shift. Using the Kubelka-Munk relation, the optical defect of MgO (4.68 eV) and Ag/MgO (3.18 eV) nanoparticles was calculated. Scanning Electron Microscope (SEM) indicated surface decorations and their pure MgO nanoparticles rod-like shape, and Energy-Dispersive X-Ray Spectroscopy (EDX) identified their elements. TEM analysis confirmed the poly-dispersive nature of the Ag decorations on the MgO surface. X-Ray Photoelectron Spectroscopy (XPS) was used to determine the valency of metal (Ag-3d) and metal oxide (Mg-2 s&O-1 s). MgO and Ag/MgO were used in visible light photocatalytic dye degradation of Rh-B dye. The biological properties were tested against S.aureus and E.coli. The plasmonic decoration on the MgO surface accelerated photodegradation and increased biological susceptibility. The innovative characteristics of this work squeeze the green synthesis of Ag/MgO nanoparticles, their improved photocatalytic and antibacterial performance, and their potential applications in water remediation and biomedicine.

Visible light-driven dye degradation by magnetic cobalt-doped zinc oxide/iron oxide photocatalyst

Zinc oxide (ZnO) serves as a photocatalyst, but it faces challenges due to its high band gap energy, limiting photoactivation to ultraviolet irradiation and rendering it scarcely recoverable after degradation. This work focuses on enhancing the photocatalytic efficiency of ZnO through cobalt doping and immobilization onto magnetic iron oxide (Fe3O4) via co-precipitation. The concentration of the cobalt precursor (0–10 mol %) and the molar ratio between Co–ZnO and Fe3O4 (5:1–15:1) were varied to achieve the optimal degradation efficiency and magnetic properties. Characterization tools such as the scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), attenuated total reflectance – Fourier-transform infrared spectroscopy (ATR-FTIR), and X-ray diffraction analysis (XRD) were utilized to evaluate the effect of cobalt doping on the physicochemical properties of the developed photocatalyst. Tauc plots indicated that 5 mol % Co–ZnO (Co5–ZnO) had the smallest band gap energy (2.79 eV), resulting in the highest photodegradation of methylene blue (88.72 %), compared to pristine ZnO (74.88 %) with a band gap energy of 3.39 eV. Co–ZnO/Fe3O4 showed a slight degradation efficiency decline, reaching a minimum of 84.53 % for the 5:1 molar ratio. These photocatalysts exhibited magnetic properties, with recovery efficiency ranging between 69.8 % and 72 %. Active radicals trapping experiments confirmed the involvement of holes, hydroxyl, and superoxide radicals in the degradation process, with superoxide radicals playing the most significant roles. In summary, this study successfully demonstrated that the synthesized Co–ZnO photocatalysts gained visible light sensitivity, and the incorporation of Fe3O4 imparted magnetic separability to the composite, thereby facilitating photocatalyst recovery.