修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

122 条数据
?? 中文(中国)
  • Development of Carbon Quantum Dota??Labeled Antibody Fluorescence Immunoassays for the Detection of Morphine in Hot Pot Soup Base

    摘要: Morphine is the most representative characteristic alkaloid existed in the extract solution of poppy shell. The analysis of morphine can be used to judge whether poppy shell is illegally added to the hot pot soup base. A sensitive, environmental-friendly carbon quantum dots (C-Dots)–based fluorescence immunoassay (C-Dots-FLISA) was developed to detect morphine (MOP). Novel water-soluble C-Dots were synthesized using a one-step hydrothermal reaction, with citric acid serving as the carbon source and ethylene diamine acting as the nitrogen source. Moreover, the C-Dots displayed blue fluorescence with an emission peak at 440 nm (350 nm excitation), which also showed good stability. C-Dots which contained amine were used to conjugate with anti-morphine antibody by glutaraldehyde as coupling reagents. The anti-morphine antibody–labeled C-Dots (Abs-labeled C-Dots) were characterized by fluorescence spectrum, transmission electron microscopy (TEM), and gel electrophoresis. C-Dots-FLISA was developed and applied to quantitative detection of morphine. Under the optimal conditions, the linear range spanned from 3.2 × 10?4 to 10 mg/L (R2 = 0.992), and the detection limit was 3 × 10?4 mg/L. These results demonstrated that the developed C-Dots-FLISA could be applied as a sensitive and convenient tool for rapid detection of morphine.

    关键词: Fluorescence immunoassay,Carbon quantum dots,Anti-morphine antibody,Morphine,Hot pot soup base

    更新于2025-09-23 15:19:57

  • Blue luminescence carbon quantum dots derived from oil palm empty fruit bunch biomass

    摘要: Carbon quantum dots (CQDs) have attracted tremendous attention for their interesting properties such as excellent chemical and photo stability, good water dispersibility, biocompatibility and possessing outstanding photoluminescence (PL) properties. In this study, oil palm biomass is used as the carbon precursor to produce CQDs and exhibit high luminescent properties. However, a large amount of biomass produces by the oil palm industry is either burnt in the open air or disposed in waste ponds and contributes to global climate change via emissions of carbon dioxide and methane. Hence, synthesis the CQDs from oil palm biomass by hydrothermal treatment method has formed excellent properties in optical properties that could be comparable to semiconductor quantum dots. The results have shown the diameter size of CQDs in the range of 2-5 nm. While, the optical properties, UV-vis spectrum of CQDs have given a strong absorption at 282 nm and obtains in brown color under visible light and emitting blue luminescence under 365 nm of UV lamp. Furthermore, PL spectra of CQDs have shown excitation and emission wavelength at 360 nm and 450 nm, respectively. This is attribute to the excitation-wavelength dependent of PL properties. Hence, the spectra from FTIR showed the existence of hydroxyl and carboxyl groups on the CQDs would have originated from lignocellulosic materials, thus resulted in excellent water stability and solubility properties of CQDs. The presented study is the green approached reprocessed biomass from waste to materials with excellent optical properties that could utilize in various field of applications.

    关键词: hydrothermal treatment,photoluminescence,optical properties,Carbon quantum dots,oil palm biomass

    更新于2025-09-23 15:19:57

  • Carbon quantum dots modified anatase/rutile TiO2 photoanode with dramatically enhanced photoelectrochemical performance

    摘要: Titanium dioxide (TiO2) is a promising photoanode material for photoelectrochemical (PEC) water splitting, but the severe bulk recombination of photongenerated carriers, the sluggish oxygen evolution reaction (OER) kinetics and the poor visible light response are the main bottleneck problems. Here, the carbon quantum dots (CQDs) modified anatase/rutile TiO2 photoanode (CQDs/A/R-TiO2) was designed by growth of anatase TiO2 nanothorns on the rutile TiO2 nanorods and further surface modification of CQDs. The results revealed that A/R-TiO2 heterojunction significantly suppressed the bulk recombination of photogenerated carriers. With further incorporation of CQDs into A/R-TiO2, dramatical improvement of OER kinetics and light harvesting were obtained. The bulk charge separation efficiency (ηbulk) and the surface charge injection efficiency (ηsurface) of CQDs/A/R-TiO2 are 1.69 and 5.74 times higher than that of the pristine TiO2 at 0.6 V vs. RHE, respectively. The photocurrent of CQDs/A/R-TiO2 is increased by 11.72 times and the onset potential of CQDs/A/R-TiO2 is negatively shifted by 240 mV.

    关键词: Anatase/rutile TiO2 heterojunction,Carbon quantum dots,Bulk and surface charge transfer kinetics,PEC,Light harvesting

    更新于2025-09-23 15:19:57

  • Upconverting carbon quantum dots: An eco-friendly material for light energy harvesting and bio-imaging

    摘要: Eco-friendly carbon quantum dots (CQDs) are finding many applications in the field of chemical sensing, photocatalytic applications, photovoltaic applications, bio-imaging, etc. Herein, CQDs are grown via a cost-effective manner, where the lemon and onion extracts are used as the reaction precursors. Formed CQDs are characterized using electronic spectroscopic and microscopic techniques. The emission yield of the present CQDs is found to be 11.2%. In contrast to general fluorophores/ semiconductors, this material showed an upconverting photoluminescence. Upon exciting with a lower energy continuous wave light of 695 nm, we observed an upconverted emission centered at 438 nm. For upconversion, as the excitation wavelength is at the lower energy, the photodecomposition of the material will be minimum. This will increase the efficiency and the lifetime of the light harvesting devices as the photodecomposition is minimum at lower wavelengths. Also, upconverting CQDs can be a potential candidate for the bio-imaging applications as the light induced decomposition of the biological samples will be minimum.

    关键词: Eco-friendly material,Carbon quantum dots,Light harvesting applications,Upconversion

    更新于2025-09-23 15:19:57

  • Phytochemical properties and antioxidant activity of Echinops persicus plant extract: green synthesis of carbon quantum dots from the plant extract

    摘要: Echinops persicus is a species of Echinops that can be found in Europe and western Asia especially in Iran. In this paper, the phytochemical properties of Echinops persicus were thoroughly investigated and studied. In this way, total amounts of flavonoid, tannins, phenols, carotenoids, saponins, alkaloids, and anthocyanin were measured by various analytical methods. The major phenolic and flavonoid content was found in the root acetone and flower ethanolic extract of the plant. Also, major saponins and carotenoid contents was found in root and leaf of the plant. These measurements were also performed for root, leaf, and flower of the plant in various solvent extracts. The results indicated that Echinops persicus is a rich source of secondary metabolites. Also, the plant extract demonstrated a considerable antiradical activity, which evaluated qualitatively as well as quantitatively. The largest capacity to neutralize DPPH radicals was found for root water extract of Echinops persicus plant. Finally, the possibility of the plant extract was evaluated for the green preparation of carbon quantum dots (CQDs). As-prepared CQDs were characterized by TEM, HRTEM, UV–Vis, XRD, and EDX analyses.

    关键词: Antioxidant,Echinops persicus,Secondary metabolites,Green preparation of CQDs,Carbon quantum dots

    更新于2025-09-23 15:19:57

  • Synthesis of 3D CQDs/urchin-like and yolk-shell TiO2 hierarchical structure with enhanced photocatalytic properties

    摘要: A novel CQDs/TiO2 hierarchical structure with enhanced photocatalytic properties was achieved by uniformly decorating urchin-like and yolk-shell TiO2 microspheres (UYTMs) with carbon quantum dots (CQDs) through an environmentally friendly hydrothermal process. The CQDs were ?rstly synthesized by the electrochemical method, and the TEM, Raman and PL characterizations strongly indicated that the as-prepared CQDs exhibited good dispersion, high crystallinity and unique up-conversion properties. The UYTMs synthesized by a NaOH-assisted hydrothermal process showed stable 3D hierarchical structure and large surface area, which was bene?cial for light absorption and contacting with contamination. The good combination of CQDs and UYTMs was further successfully achieved during the hydrothermal process, and demonstrated by a series of tests. The photocatalytic experiments suggested that the CQDs/UYTMs exhibited better photocatalytic activities than the pure UYTMs and P25 under both visible and UV light irradiation. The CQDs/UYTMs combining with 6 wt% of CQDs showed the best photocatalytic e?ciency, while excessive CQDs tended to inhibit the photocatalytic activity. According to the results and discussions, a possible mechanism in improving the photocatalytic e?ciency of the CQDs/UYTMs is signi?cantly proposed. The up-conversion property of CQDs can broaden the absorption spectrum of CQDs/UYTMs to the visible light. Moreover, the CQDs, as the electron reservoirs, are e?cient to separate the electrons and holes, leading to an improved photocatalytic activity of CQDs/UYTMs.

    关键词: Carbon quantum dots,Urchin-like microspheres,Photocatalytic activity,TiO2,Yolk shell

    更新于2025-09-23 15:19:57

  • Polyurethane-Supported Graphene Oxide Foam Functionalized with Carbon Dots and TiO2 Particles for Photocatalytic Degradation of Dyes

    摘要: The design and optimal synthesis of functional nanomaterials can meet the requirements of energy and environmental science. As a typical photocatalyst, TiO2 can be used to degrade dyes into non-toxic substances. In this work, we demonstrated the in-situ hydrothermal synthesis of carbon quantum dots (CQDs)-modified TiO2 (CQDs/TiO2) particles, and the subsequent fabrication of three-dimensional (3D) graphene oxide (GO) foam doped with CQDs/TiO2 via a facile strategy. By making full use of the up-conversion characteristics of CQDs, the synthesized CQDs/TiO2 exhibited high catalytic activity under visible light. In order to recover the photocatalyst conveniently, CQDs/TiO2 and GO were mixed by ultrasound and loaded on 3D polyurethane foam (PUF) by the multiple impregnation method. It was found that GO, CQDs/TiO2, and PUF reveal synergistic effects on the dye adsorption and photocatalytic degradation processes. The fabricated 3D CQDs/TiO2/GO foam system with a stable structure can maintain a high photocatalytic degradation efficiency after using at least five times. It is expected that the fabricated 3D materials will have potential applications in the fields of oil water separation, the removal of oils, and the photothermal desalination of seawater.

    关键词: carbon quantum dots,graphene oxide,TiO2,photocatalysis,water purification

    更新于2025-09-19 17:15:36

  • Carbon quantum dots implanted CdS nanosheets: Efficient visible-light-driven photocatalytic reduction of Cr(VI) under saline conditions

    摘要: Chromium(VI) (Cr(VI)), a toxic metal, is generally present together with ionic salts in industrial effluents. An efficient reduction of Cr(VI) to Cr(III) in saline water is an imperative issue but still a challenging task. Literature has rarely addressed reducing Cr(VI) effectively under saline conditions. Herein, carbon quantum dots (CQDs) were successfully implanted in the CdS nanosheets (CdS-NSs) to prepare nanocomposites (i.e., CCNs) for the first time to efficiently reduce Cr(VI) to Cr(III). The newly fabricated CCNs demonstrated superior performance to reduce Cr(VI) compared to pristine CdS-NSs and CQDs-deposited CdS nanosheets (i.e., CQD/CdS-NSs) in saline water. The nanostructures were examined by spectral and photoelectrochemical measurements as well as density functional theory (DFT) calculations. Results showed that CCNs facilitated the photo-electron transport and thus suppressed charge recombination via formation of micro-regional heterostructures. A lower band gap of CCNs relative to pristine CdS-NSs and CQD/CdS-NSs extended the light absorption spectrum. The optimal photocatalyst, denoted as CCNs-2, exhibited an efficiency of ~94% for photocatalytic Cr(VI) reduction within 10 min in water containing 1200 mg/L salts. The obtained rate constant of reduction of Cr(VI) was (2.62 ± 0.04) × 10-1 min-1, approximately 4 and 3 times higher than that of pristine CdS-NSs and CQD/CdS-NSs, respectively. After 3 cycles, the CCNs-2 still showed an efficiency of ~78% aqueous Cr(VI) reduction within 10 min. Our results clearly presented that implantation relative to deposition of CQDs for CdS-NSs is a preferential strategy to enhance photocatalytic Cr(VI) reduction in saline water under visible light irradiation.

    关键词: Saline water,Implantation,Photocatalytic Cr(VI) reduction,Carbon quantum dots,Cadmium sulfide nanosheets

    更新于2025-09-19 17:13:59

  • Principles, mechanisms, and application of carbon quantum dots in sensors: a review

    摘要: The Carbon quantum dots (CQDs) as an emerging class of quantum dots (QDs) with advantages such as good photoluminescence (PL) properties, easy synthesis routes, economical synthesis, cheap starting materials, water-solubility, low level of toxicity, chemical stability, and easy functionalization have received great attention during recent years. The CQDs have been used in versatile sensor applications. The CQDs sensors could be ultimately sensitive, and the limit of detection (LOD) for these sensors can reach the nanomolar, picomolar or even femtomolar ranges. The CQDs-based sensors and biosensors work with different mechanisms including fluorescence quenching, static quenching, dynamic quenching, energy transfer, inner filter effect (IFE), photo-induced electron transfer (PET), and fluorescence resonance energy transfer (FRET). The CQDs-based sensors and biosensors have been applied for detection of different species such as metal ions, acids, proteins, biothiols, polypeptides, DNA and miRNA, water pollutants, hematin, drugs, vitamins, and other chemicals. It seems that the CQDs-based sensors and biosensors are promising candidates for high performance and yet accurate sensors in different areas. In this review, the CQDs are introduced, and the synthesis methods and optical properties of the CQDs are discussed. Different types of CQDs-based sensors and biosensors and their working mechanisms are clarified.

    关键词: Carbon quantum dots,Sensors,Electrochemiluminescence,Photoluminescnece,Chemiluminescence,Fluorescence resonance energy transfer

    更新于2025-09-19 17:13:59

  • SILICA a?? CARBON QUANTUM DOTS DECORATED TITANIUM DIOXIDE AS SUNLIGHT-DRIVEN PHOTOCATALYST TO DIMINISH ACETAMINOPHEN FROM AQUATIC ENVIRONMENT

    摘要: The presence of pharmaceutical compound (i.e., acetaminophen) in aquatic environment has been declared as environmental issue since researchers found that it has potential risk to human health. Photocatalytic process as a promising method for waste degradation commonly employs titanium dioxide, TiO2. However, TiO2 has narrow light absorption and rapid charge recombination resulting in ineffective photocatalytic activity. In this study, silica – carbon quantum dots (Si-CQDs) from rice husk are decorated into TiO2 matrix through facile mixing approach to minimize the limitations of TiO2. Preliminary studies regarding TiO2 transformation and Si-CQDs incorporation in various amount were systematically investigated. It is observed that 1 wt% is the optimum amount of Si-CQDs in composite in order to maximize the photocatalytic ability of TiO2. Under sunlight irradiation, 1 wt% Si-CQDs/TiO2 composite is able to completely degrade 5 mg/L of acetaminophen within 240 min (33.3% faster than pure TiO2). The excellent performance of the composite is attributed to synergistic effect of Si-CQDs addition on TiO2 surface, which acted as photo sensitizer and electron trapper. Si-CQDs extend light absorption of TiO2 by reducing band gap energy from 3.20 to 3.12 eV, as confirmed by UV-Vis Diffuse Reflectance Spectroscopy (DRS) spectra. Photoluminescence (PL) spectra and N2 sorption isotherm reveal that Si-CQDs addition prolongs the lifetime of charge separation and improves surface area (17% larger than TiO2), respectively. The composite of Si-CQDs/TiO2 also demonstrates good stability which is beneficial for pharmaceutical waste removal in the future.

    关键词: sunlight,photocatalyst,Titanium dioxide,acetaminophen,carbon quantum dots,pharmaceutical

    更新于2025-09-19 17:13:59