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Photophysicochemical properties and photodynamic therapy activity of chloroindium(III) tetraarylporphyrins and their gold nanoparticle conjugates
摘要： Novel chloroindium(III) complexes of tetra(4-methylthiophenyl)porphyrin (2a) and tetra-2-thienylporphyrin (2b) dyes have been synthesized and characterized. The main goal of the project was to identify fully symmetric porphyrin dyes with Q-band regions that lie partially in the therapeutic window that are suitable for use in photodynamic therapy (PDT). 2a and 2b were found to have fluorescence quantum yield values ≤ 0.01 and moderately high singlet oxygen quantum yields (0.54?0.73) due to heavy atom effects associated with the sulfur and indium atoms. The dark toxicity and PDT activity against epithelial breast cancer cells (MCF-7) were investigated over a dose range of 3.0?40 mg . mL-1. The in vitro dark cytotoxicity of 2a is significantly lower than that of 2b at ≤ 40 mg . mL-1. 2a was conjugated with gold nanoparticles (AuNPs) to form a nanoconjugate (2a-AuNPs), which exhibited a higher singlet oxygen quantum yield (FD) value and PDT activity than was observed for 2a alone. The results suggest that the AuNPs nanoconjugates of readily synthesized fully symmetric porphyrin dyes are potentially suitable for PDT applications, if meso-aryl substituents that provide scope for nanoparticle conjugation can be introduced that shift the Q bands into the therapeutic window.
关键词： porphyrins,photophysics,dark toxicity,singlet oxygen,gold nanoparticles,photodynamic therapy
更新于2025-09-23 15:22:29
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A Guide to Small-Scale Energy Harvesting Techniques || Quest for Lead-Free Perovskite-Based Solar Cells
摘要： Today, the perovskite solar cells (PSCs) are showing excellent potentials in terms of simple processing, abundance of materials, and architectural integration, as well as very promising device’s power conversion efficiencies (PCEs), rocketed from 3.8% in 2009 to 23.3% in 2018. However, the toxic lead (Pb) element containing the chemical composition of typically used organic-inorganic halide perovskites hinders the practical applications of PSCs. This chapter starts with a general discussion on the perovskite crystal structure along with the serious efforts focused on Pb replacement in these devices. Section 2 will elaborate the fundamental features of tin (Sn)-based perovskites together with their performance in the PSCs. Other alternative elements, such as copper (Cu), germanium (Ge), bismuth (Bi), and antimony (Sb), will be discussed in Section 3. The end will summarize the challenges and opportunities based on the chapter contents.
关键词： stability,lead-free perovskites,chemical composition,toxicity
更新于2025-09-23 15:21:01
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Degradation of Ciprofloxacin and Inactivation of Ciprofloxacin Resistant E. Faecium during UV-LED (275 nm)/Chlorine Process
摘要： Ciprofloxacin and ciprofloxacin-resistant bacteria are emerging concerns that threaten public health due to the heavy use of antibiotics and the development of bacterial resistance in water environments. In this study, we examined an energy-efficient treatment driven by a UV-LED/chlorine reaction with UV-LED chip emitting UV275 nm to remove ciprofloxacin and ciprofloxacin-resistant bacteria in water. Ciprofloxacin degradation during the UV-LED/chlorine reaction followed pseudo-first-order kinetics, and the excessive chlorine dosage has a negative effect on ciprofloxacin removal. Alkaline pH showed the best efficiency for ciprofloxacin removal, and the reactive chlorine species (RCS) played a major role at alkaline pH values. The cleavages of piperazine, cyclopropyl, and quinolone moieties are considered as the principal degradation reactions in the UV-LED/chlorine reaction. Seven byproducts (m/z = 362.9262, 306.1246, 289.0995, 288.1504, 263.0825, 147.0657, and 1183.9977), two chlorinated compounds (chloroform and chlorate) and two anions (formate and nitrate ions) were observed as the identified byproducts. Toxicity of tentatively identified byproducts were estimated by using quantitative structure activity relationship (QSAR). The complete detoxification of D. magna was achieved when applying UV-LED/chlorine process into hospital wastewater containing CIP. The UV-LED/chlorine process showed the best disinfection ability of E. faecium compared to UV-LED photolysis, chlorination, and UV-LED/H2O2 reactions. A significantly lower EE/O value (6.63 × 10-2 kWh/m3/order) during the UV-LED/chlorine reaction was also observed. Our results indicate that the UV-LED/chlorine process can effectively degrade ciprofloxacin and inactivate ciprofloxacin-resistant bacteria.
关键词： toxicity,UV-LED,ciprofloxacin,byproducts,antibiotic-resistant bacteria,Chlorine
更新于2025-09-23 15:21:01
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Protein Corona Formation of Human Serum Albumin with Carbon Quantum Dots from Roasted Salmon
摘要： As the food-borne nanoparticles enter the biological system, they will contact with various proteins to form protein coronas, which can affect their physicochemical properties and biological identity. In this study, the protein corona formation of carbon quantum dots (CQDs) from roast salmon with human serum albumin (HSA), as well as biological identity involving cell apoptosis, energy, glucose and lipid metabolism and acute toxicity in mice, were investigated. The HSA-CQD coronas formed between HSA and CQDs via static binding mechanism, and the binding site of CQDs on HSA located both in Sudlow’s site I and site II. The HSA-CQD coronas entered the cytoplasm and present in lysosomes or autolysosomes. Importantly, the HSA coronas mitigated the cytotoxicity of CQDs from 18.65% to 9.26%, and the energy metabolism was rectified from glycolytic to aerobic metabolism. The glucose and lipid metabolite profile of the HSA-CQD coronas differed from that of the CQDs, indicating that HSA-CQD coronas rectified disturbance in metabolism. Histopathological and blood biochemical analysis revealed no statistically significant difference between the testing and control mice after a single CQDs dose of 2000 mg/kg body weight. Overall, the results confirmed the formation of protein corona between HSA and food-borne fluorescent CQDs, and could be helpful for evaluating the safety of fluorescent CQDs from roast food items.
关键词： cytotoxicity,acute toxicity,protein coronas,human serum albumin,carbon quantum dots,metabolism,food-borne nanoparticles
更新于2025-09-23 15:21:01
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Influence of Carbon Quantum Dots on the Biome
摘要： The latest class of engineered nanomaterials, viz., carbon quantum dots (CQDs), has attracted attention because they are synthesized through green chemical procedures and from organic waste matter. The synthesis of these nano-sized particles synthesized from biomass such as fruit peel and other organic matter results in mixtures of CQD species that di?er in chemical identity, activity and photo-physical properties. Generally used collectively as chemically heterogeneous ensemble, they have already had an impact on multiple sectors of our environment by use as wastewater sensors, switches, model agro-fertilizers, and in biomedicine. The transitioning of their applications to crops is an important crossover point that calls for an accurate and detailed assessment of their genomic, proteomic, and metabolomics impact on agriculturally important crops and produce. We review the current status of CQDs vis-à-vis their impact on the biosphere via recent model studies and comment on the knowledge gaps that need to be bridged to ensure their safe use in agronomy. A detailed knowledge of their impact on aquatic systems and the food-chain is critical for human and environmental safety and sustainability.
关键词： agriculture,environmental implications,Carbon Quantum Dots,toxicity
更新于2025-09-23 15:21:01
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Highly Efficient Energy Transfer from Water Soluble Zinc Silver Indium Sulphide Quantum Dot to Organic J-Aggregates
摘要： The present work has been carried out with an aim to design and develop an efficient light harvesting inorganic-organic hybrid nanoscale material by employing less toxic, environment friendly inorganic substance and also to understand the mechanism of inter-particle electronic interaction between the inorganic and organic components of the nanomaterial. Specifically, the inorganic-organic hybrid associate has been made by integrating water soluble semiconductor QDs (Zinc-silver-indium-sulfide (ZAIS)) and organic J-aggregates of a cyanine dye (S2165). The fabrication of present nano-hybrid system has been achieved via electrostatically driven self-assembly of organic dyes over ZAIS QDs. The interaction between QD and J-aggregates have been investigated by steady state and time resolved fluorescence measurements. Zeta potential measurements have also been performed to understand the role of electrostatic interaction and thermodynamic feasibility of the association process. The investigations have revealed that energy transfer (ET) process between QD and J-aggregates mediated through dipole-dipole mechanism. Interestingly, data analysis based on F?rster theory has further revealed that the ET from QD to J-aggregates is very high indicating efficient electronic coupling between the inorganic QD and the organic J-aggregates. Zeta potential measurements and thermodynamic calculations have demonstrated that the interaction between QD and organic dye is electrostatically driven and the association of organic dyes over QD is thermodynamically feasible. The outcome of the present study is expected to be helpful in designing efficient nanoscale light harvesting devices. Additionally, fluorescence microscopy and toxicity studies on the QDs have also shown its suitability for biological applications.
关键词： energy transfer,fluorescence microscopy,electrostatic interaction,J-aggregates,inorganic-organic hybrid,toxicity studies,quantum dots
更新于2025-09-23 15:21:01
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Ergebnisse spektraler optischer Koh?renztomografie bei den mit Chloroquin behandelten Patienten mit systemischem Lupus erythematodes
摘要： Purpose To recognise possible retinal changes in patients with SLE treated with chloroquine phosphate, as depending on the duration of treatment. Methods The study included 41 patients (82 eyes) who received treatment for SLE with chloroquine or hydroxychloroquine phosphate and had not previously been diagnosed with retinal pathology. Participants were divided into two groups according to the duration of treatment. The first group included 18 patients (36 eyes) treated for up to five years and the second group consisted of 23 patients (46 eyes) treated from five to twenty years. We performed a thorough eye exam, including best-corrected visual acuity, colour vision, visual field examination, dilated fundus examination, auto-fluorescence imaging, color fundus photography and spectral domain optical coherence tomography. Results Mean duration of treatment in the first group was 2.79 ± 1.37 years, and in the second group 8.67 ± 2.26 years. The difference in central retinal thickness between the two groups was not statistically significant (p > 0.05). Comparison of parafoveal thickness between the two groups was statistically non-significant in all quadrants (p > 0.05). Visual field examination, autofluorescence images and colour fundus photographs were without noteworthy pathology. Conclusion Our results indicate that there were no significant changes in retinal structure between groups that depended on the duration of treatment. Hence, we can conclude that a yearly follow-up of these patients is sufficient to discover possible preclinical maculopathy.
关键词： systemic lupus erythematosus,hydroxychloroquine,retinal toxicity,optical coherence tomography
更新于2025-09-23 15:21:01
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Aluminum foil as a substrate for metal enhanced fluorescence of bacteria labelled with quantum dots, shows very large enhancement and high contrast
摘要： Very high surface/metal enhanced fluorescence was observed for E. coli single bacteria cells labeled with composite CdSeS/ZnS quantum dots (QDs) on three substrates: aluminum foil, aluminum film and gold film. The enhancement factors relative to maximum fluorescence intensity on glass for those substrates were in the range of several hundred (up to 500) for two-excitation wavelengths 532 and 633 nm. Contrast as a ratio of signals from QD labeled to signals of QD unlabeled (control) cells was also in the range of 100 s for those substrates and the highest contrast of 370 was observed on Al film. When CdTe QDs were used for labelling cells on all substrates or when fluorescence from cells with both QDs was measured on silver film, low or no enhancement was observed. Overall, untreated aluminum foil demonstrated great potential as low-cost substrate for surface/metal enhanced fluorescence, which delivers even more reproducible signal than gold film.
关键词： E. coli,Bacteria,Enhancement facor,Quantum dots,Single bacterial cell detection,Metal enhanced fluorescence,Contrast,Surface enhanced fluorescence,Aluminum foil,QD toxicity
更新于2025-09-23 15:21:01
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Comparison of acetaminophen degradation in UV-LED-based advance oxidation processes: Reaction kinetics, radicals contribution, degradation pathways and acute toxicity assessment
摘要： Ultraviolet light emitting diode (UV-LED)-based advanced oxidation processes (AOPs) including UV-LED/chloramine (UV-LED/NH2Cl), UV-LED/hydrogen peroxide (UV-LED/H2O2) and UV-LED/persulfate (UV-LED/PS), were adopted for acetaminophen (AAP) removal. Results showed that AAP could be effectively degraded by the hybrid processes compared to solely using with UV irradiation and oxidants. The AAP degradation in the three UV-LED-based AOPs were in the order of UV-LED/PS N UV-LED/H2O2 N UV-LED/NH2Cl and followed a pseudo-?rst-order kinetics. The degradation rate constant (kobs) increased with increasing oxidant dosage, whereas overdosing lowered the AAP degradation. The second-order rate constants of HO?, SO4??, and Cl? with AAP were calculated as 5.15 × 109, 7.66 × 109 and 1.08 × 1010 M?1 s?1, respectively. Under neutral conditions, the contributions of UV-LED, HO?, and Cl? to AAP degradation were 4.21%, 60.15% and 35.64% in the UV-LED/NH2Cl system, whereas the respective contributions of UV-LED, HO? and SO4?? to AAP degradation were 2.09%, 22.84% and 75.07% in UV-LED/PS system, respectively. Meanwhile, the corresponding contributions of the involved reactive species were found to be pH-dependence. The natural organic materials (NOM) inhibited the ? had different effects on AAP degradation in the ?, and NO3 AAP degradation, and the presence of Cl?, HCO3 three hybrid processes. The AAP degradation was signi?cantly inhibited in the three UV-LED-based AOPs in real water. In addition, the intermediate products were also identi?ed, and possible degradation pathways were proposed in the three UV-LED-based AOPs. The acute toxicity bioassay using bacterium Vibrio ?scheri suggested that the UV-LED/PS process was more effective than the UV-LED/H2O2 and UV-LED/NH2Cl processes in reducing the acute toxicity of the reacted AAP solution. Among the three UV-LED-based AOPs, the UV-LED/PS was found to be the most ef?cient process for AAP degradation.
关键词： Acute toxicity,Rate constants,UV-LED-based AOPs,Degradation pathways,Acetaminophen
更新于2025-09-23 15:21:01
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Enhanced solar- photocatalytic activity for the simultaneous degradation and detoxification of multiple chlorophenols by embedding plasmonic Pt into TiO2/H3PW12O40 nanopore
摘要： A novel Pt-TiO2/H3PW12O40 film was fabricated, which showed a considerable nonselective degradation and detoxification efficiency towards multiple chlorophenols (CPs), owing to the enhanced yield and separation efficiency of photogenerated electrons and holes. Based on the Mott-Schottky analysis, the carrier density of as-prepared Pt-TiO2/H3PW12O40 film reached 9.72 × 1022 cm?1, which was higher than that of Pt-TiO2, TiO2/H3PW12O40, and TiO2. The outstanding properties were attributed to the SPR effect and the formation of electrons traps from Pt0 (which was well protected by the nanopores that were formed by Ti-O-W and Ti-O-P); and H3PW12O40 that can efficiently transport electrons via its self-generated redox cycle. Meanwhile, the Pt-TiO2/H3PW12O40 film considerably lowers ecological risks of multiple CPs because O2?, as the primary radicals, can largely avoid the generation of products with a quinoid structure. The degradation pathways of multiple CPs were similar to those of single CP because the same hydroxyl substitution intermediate products were detected during the degradation, all of which followed the first-order reaction kinetics. Moreover, the excellent recycling performance of the Pt-TiO2/H3PW12O40 film guaranteed the reduction in economic cost and risks of secondary pollution. Therefore, the Pt-TiO2/H3PW12O40 film showed a considerable application potential in the removal of organic contaminants in aqueous environments.
关键词： Acute toxicity,Schottky junction,SPR effect,Multiple CPs,Degradation pathway
更新于2025-09-23 15:19:57