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3D Ultrasensitive Polymers-Plasmonic Hybrid Flexible Platform for In-Situ Detection
摘要： This paper introduces a three-dimensional (3D) pyramid to the polymers-plasmonic hybrid structure of polymethyl methacrylate (PMMA) composite silver nanoparticle (AgNPs) as a higher quality flexible surface-enhanced Raman scattering (SERS) substrate. Benefiting from the effective oscillation of light inside the pyramid valley could provide wide distributions of 3D 'hot spots' in a large space. The inclined surface design of the pyramid structure could facilitate the aggregation of probe molecules, which achieves highly sensitive detection of rhodamine 6G (R6G) and crystal violet (CV). In addition, the AgNPs and PMMA composite structures provide uniform space distribution for analyte detection in a designated hot spot zone. The incident light can penetrate the external PMMA film to trigger the localized plasmon resonance of the encapsulated AgNPs, achieving enormous enhancement factor (~6.24 × 108). After undergoes mechanical deformation, the flexible SERS substrate still maintains high mechanical stability, which was proved by experiment and theory. For practical applications, the prepared flexible SERS substrate is adapted to the in-situ Raman detection of adenosine aqueous solution and the methylene-blue (MB) molecule detection of the skin of a fish, providing a direct and nondestructive active-platform for the detecting on the surfaces with any arbitrary morphology and aqueous solution.
关键词： PMMA,AgNPs,adenosine,SERS,methylene-blue,in-situ
更新于2025-09-19 17:13:59
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Waste to wealth translation of e-waste to plasmonic nanostructures for surface-enhanced Raman scattering
摘要： Here we report, for the first time, a simple one-step recycling of discharged batteries, a major constituent of electronic waste (e-waste), into value-added fluorescent nanomaterials-carbon quantum dots (CQDs). The e-waste derived CQDs (eW-CQDs) were systematically characterized for their optical properties, including absorption, photoluminescence, quantum yield, and emission lifetime. The morphology of these nanomaterials was determined by high-resolution transmission electron microscopy, selected area electron diffraction, and X-ray diffraction, whereas Raman spectroscopy was used to confirm their carbonaceous architecture. To broaden the range of applications, the eW-CQDs were employed in the synthesis of plasmonic nanostructures (eW-Au@CQDs) via a one-step chemical reduction strategy. Both eW-CQDs and eW-Au@CQDs were further tested for their suitability to be used as surface-enhanced Raman (SERS) substrates for the detection of methylene blue (MB), a model dye and Raman reporter. Our results show that while eW-CQDs are not ideal for SERS applications, eW-Au@CQDs, when deposited on a gold-modified screen-printed carbon electrode (SPE), produce strong MB SERS signals. With further optimization, these eW-Au@CQDs-modified SPEs could find applications in SERS-based sensing. This study demonstrates a new, promising, and sustainable approach of converting e-waste such as discharged batteries into value-added products with potential for a wide range of applications.
关键词： E-waste,Discharged batteries,Recycling,SERS,Carbon quantum dots,Methylene blue
更新于2025-09-19 17:13:59
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Controlled synthesis of Ag-doped CuO nanoparticles as a core with poly(acrylic acid) microgel shell for efficient removal of methylene blue under visible light
摘要： Nowadays, constructing a narrow bandgap nanocomposite photocatalyst that can degrade contamination under visible light is critical but challenging. In this report, poly (acrylic acid) microgel (PAA) based nanocomposites (Ag@CuO/PAA NC) were constructed via free radical solution polymerization by varying the concentration of silver-doped copper oxide nanoparticles (Ag@CuO NPs) from 0 to 12%. As prepared Ag@CuO and Ag@CuO/PAA were characterized by X‐ray diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray and X-ray photoelectron spectroscopy. The size of Ag@CuO NPs was found to be 30–50?nm. The photocatalytic activity of CuO is increased by Ag doping and C3 NPs show the best photodegradation of methylene blue (MB). Then, 4% of Ag@CuO nanoparticles were incorporated into PAA microgel, the resultant nanocomposite showed a drastic increase in photodegradation of MB. Ag@CuO/PAA NC completely degraded dye in only 30?min which was degraded up to 65% in 60?min. by Ag@CuO NPs. The successful combination of PAA with Ag@CuO boosts the photocatalytic activity because microgel provides a large surface to adsorb pollutants. Ag@CuO/PAA NC reused successfully for photodegradation of dye due to the recycling ability of microgels. This study gives a good insight into planning a significant visible‐light‐driven photocatalyst for environmental remediation.
关键词： photocatalytic degradation,methylene blue,Ag-doped CuO nanoparticles,visible light,poly(acrylic acid) microgel
更新于2025-09-19 17:13:59
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The synthesis of Co <sub/>x</sub> Ni <sub/>1?x</sub> Fe <sub/>2</sub> O <sub/>4</sub> /multi-walled carbon nanotube nanocomposites and their photocatalytic performance
摘要： A series of CoxNi1?xFe2O4/multi-walled carbon nanotube (CoxNi1?xFe2O4/MWCNTs) nanocomposites as photocatalysts were successfully synthesized, where CoxNi1?xFe2O4 was synthesized via a one-step hydrothermal approach. Simultaneously, methylene blue (MB) was used as the research object to investigate the catalytic effect of the catalyst in the presence of hydrogen peroxide (H2O2). The results showed that all the photocatalysts exhibited enhanced catalytic activity compared to pure ferrite. In addition, compared with the other photocatalysts, the reaction time was greatly shortened a significantly higher removal rate was achieved using 3-CNF/MWCNTs. There was no significant decrease in photodegradation efficiency after three catalytic cycles, suggesting that CoxNi1?xFe2O4/MWCNTs are recyclable photocatalysts for wastewater treatment. Our results indicate that the CoxNi1?xFe2O4/MWCNT composite can be effectively applied for the removal of organic pollutants as a novel photocatalyst.
关键词： methylene blue,photocatalysts,hydrothermal approach,wastewater treatment,multi-walled carbon nanotube,hydrogen peroxide,CoxNi1?xFe2O4
更新于2025-09-16 10:30:52
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Determination of Infrared Laser Energy Dose for Cancer Cells Inactivation as a Candidate of Photodynamic Therapy
摘要： The aim of this research is to find out the effect of GaAlAs diode laser 808 nm exposure on MCF-7 breast cancer cells in vitro with and without the addition of a photosensitizer. Methylene blue (C16H18N3SCl) with concentration of 2 μM is used as the photosensitizer based on the preliminary results of cytotoxicity assay. Energy dose is set in the range of 23,043 to 322,062 J/cm2. Laser exposure with the addition of the photosensitizer generates the highest percentage of cell death of 20.80% at energy dose of 184,344 J/cm2 and cell death begin to decrease at energy dose above this value. This behavior is likely caused by photodegradation and photobleaching effect of the photosensitizer due to the longer exposure time. However, the percentage of cell death without the addition of photosensitizer is increased proportionally to the increase of energy dose and achieved 32,45% cell mortality at 299,559 J/cm2. This study not only shows that the exposure of infrared laser can be used to inactivate cancer cells but also determines its optimum energy dose, makes it a possible candidate for photodynamic therapy in the future.
关键词： MCF-7 cells,photodynamic therapy,photochemical,methylene blue,diode laser,photothermal
更新于2025-09-16 10:30:52
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Flexible organic light-emitting diodes for antimicrobial photodynamic therapy
摘要： Bacterial infection and the growth of antibiotic resistance is a serious problem that leads to patient suffering, death and increased costs of healthcare. To address this problem, we propose using flexible organic light-emitting diodes (OLEDs) as light sources for photodynamic therapy (PDT) to kill bacteria. PDT involves the use of light and a photosensitizer to generate reactive oxygen species that kill neighbouring cells. We have developed flexible top-emitting OLEDs with the ability to tune the emission peak from 669 to 737 nm to match the photosensitizer, together with high irradiance, low driving voltage, long operational lifetime and adequate shelf-life. These features enable OLEDs to be the ideal candidate for ambulatory PDT light sources. A detailed study of OLED–PDT for killing Staphylococcus aureus was performed. The results show that our OLEDs in combination with the photosensitizer methylene blue, can kill more than 99% of bacteria. This indicates a huge potential for using OLEDs to treat bacterial infections.
关键词： Photodynamic therapy,Flexible organic light-emitting diodes,Staphylococcus aureus,Antimicrobial,Methylene blue
更新于2025-09-12 10:27:22
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Synthesis, Characterization,and Photocatalytic activity of Silver nanoparticledoped Phosphomolybdic acid supportedZirconia
摘要： An ecofriendly solid acid catalyst was synthesized by impregnating phosphomolybdic acid on zirconia followed by doping with Silver nanoparticles to form composite. We report here, the synthesis, characterization and photocatalytic behavior of AgNPs doped Keggin Ions/ Zirconia which is synthesized by wet impregnation method. The resulting nanocomposite was characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy. The photocatalytic activity of the catalyst was evaluated for the degradation of azo dye under the Visible light irradiation. In the photoreaction study, it is found that photocatalytic activity increases by doping the noble metal silver nanoparticles on PMA/ZrO2 surface to form the composite.
关键词： Phosphomolybdic acid,Zirconia,Methylene blue dye,Photocatalytic activity
更新于2025-09-12 10:27:22
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Nano-sized SnO <sub/>2</sub> by a facile nanosecond laser irradiation in aqueous solution
摘要： A green and facile route was devised for the synthesis of SnO2 nanoparticles (NPs) using pulse laser irradiation of an aqueous solution of stannous chloride dihydrate and sodium hydroxide. The process employed ascorbic acid as a passivating agent, and SnO2 was obtained without any hazardous chemical reducing agent or high temperature calcination process. A nanosecond laser generating pulses with a peak wavelength of 355 nm and pulse repetition rate of 10 Hz was employed. Structural characterisations of the as-synthesized nanoparticles were carried out. The morphology of the SnO2 NPs were mostly spherical and their average crystalline sizes in the range 48.0–62.5 nm as obtained from the TEM images. The particles size showed a direct relationship with the irradiation time, and a decrease in the monodispersity was observed with increase in the time of exposure to the laser beam. The photocatalytic activity of the NPs, obtained with the least time of exposure to the laser beam, was evaluated for the photodegradation of methylene blue under visible light. The nanoparticles achieved about 84% efficiency towards the degradation of the dye within 180 min.
关键词： methylene blue,SnO2,laser irradiation,photocatalysis,nanoparticles
更新于2025-09-12 10:27:22
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New Perspectives in Surgical Marking Since the Advent of Infrared Laser Angiography
摘要： This study investigates the utility of common surgical dyes under direct visualization and infrared laser angiography. Pigments affecting light within the visual (λ = 400–700 nm) and infrared (λ = 700–1000 nm) spectra were placed on subjects spanning the Fitzpatrick scale. Photometric properties of these pigments were assessed under direct visualization and infrared laser angiography. Among patients of various Fitzpatrick classifications, black ink pigment and pigment within the violet spectrum (λ = 380–450 nm) were most distinguishable under direct visualization. Colored inks, gentian violet and methylene blue dyes, were not visualized under infrared laser angiography. Black permanent ink appeared under both direct visualization and infrared laser angiography. Indocyanine green suspended in ethyl alcohol and applied to skin as a marking pen appeared clear under direct visualization and was detectable under infrared laser angiography. Black permanent marking ink allows visualization of surgical markings under infrared laser angiography, whereas gentian violet and methylene blue did not interfere with infrared visualization. Indocyanine green suspended in ethyl alcohol is a contemporary marking pen that may be used to outline anatomical surface landmarks under infrared laser angiography.
关键词： dye,methylene blue,skin marking,surgical marking,infrared laser angiography,marking pen,indocyanine green,gentian violet,surgical planning,ink
更新于2025-09-12 10:27:22
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Investigating the efficiency of α-Bismuth zinc oxide heterostructure composite/UV-LED in methylene blue dye removal and evaluation of its antimicrobial activity.
摘要： Heterostructured α-Bismuth zinc oxide (α-Bi2O3-ZnO) photocatalyst was fabricated by a facile and cost-effective, ultrasound assisted chemical precipitation method followed by hydrothermal growth technique. As synthesized α-Bi2O3-ZnO photocatalyst showed enhanced photocatalytic performance for the MB dye degradation in contrast to pure ZnO and α-Bi2O3. Light emitting diodes (UV-LED) were used in the experimental setup, which has several advantages over conventional lamps like wavelength selectivity, high efficacy, less power consumption, long lifespan, no disposal problem, no warming-up time, compactness, easy and economic installation. XRD study confirmed the presence of both the lattice phases i.e. monoclinic and hexagonal wurtzite phase corresponding to α-Bi2O3 and ZnO in the α-Bi2O3-ZnO composite photocatalyst. FESEM images showed that α-Bi2O3-ZnO photocatalyst is composed of dumbbell like structures of ZnO with breadth ranging 4-5 μm and length ranging from 10 to 11 μm respectively. It was observed that α-Bi2O3 nanoparticles were attached on the ZnO surface and were in contact with each other. Low recombination rate of photo-induced electron-hole pairs, due to the migration of electrons and holes between the photocatalyst could be responsible for the 100 % photocatalytic efficiency of α-Bi2O3-ZnO composite. In addition, photocatalyst was also observed to show the excellent antimicrobial activity with 1.5 cm zone of inhibition for 1 mg/L dose, against the human pathogenic bacteria (S. aureus).
关键词： Heterostructure,antimicrobial activity,Methylene blue,Photocatalyst,α-Bi2O3-ZnO,UV-LED,α-Bi2O3
更新于2025-09-11 14:15:04