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Modification of nanocrystalline TiO <sub/>2</sub> coatings with molecularly imprinted TiO <sub/>2</sub> for uric acid recognition
摘要： Combining the surface modification and molecular imprinting technique, a novel piezoelectric sensing platform with excellent molecular recognition capability was established for the detection of uric acid (UA) based on the immobilization of TiO2 nanoparticles onto quartz crystal microbalance (QCM) electrode and modification of molecularly imprinted TiO2 (MIT) layer on TiO2 nanoparticles. The performance of the fabricated biosensor was evaluated, and the results indicated that the biosensor exhibited high sensitivity in UA detection, with a linear range from 0.04 to 45 μM and a limit of detection of 0.01 μM. Moreover, the biosensor presented high selectivity towards UA in comparison with other interferents. The analytical application of the UA biosensor confirmed the feasibility of UA detection in urine sample.
关键词： highly selective detection,uric acid biosensor,piezoelectric sensing,surface modification,molecularly imprinted TiO2
更新于2025-09-23 15:23:52
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Could a chelant improve the effect of curcumin-mediated photodynamic antimicrobial chemotherapy against dental intact biofilms?
摘要： To our knowledge, there is still no evidence in relation to the combination of curcumin with chelants to improve the effects of antimicrobial photodynamic therapy (aPDT) on complex dental caries biofilms. Therefore, the aim of this study was to evaluate the antimicrobial effect of curcumin-ethylenediaminetetraacetic acid (EDTA)-mediated aPDT on the vitality of intact biofilms of dentin caries microcosms. Biofilms were grown on glass slabs in McBain medium plus 1% sucrose in microaerophily at 37 °C for 5 days. Then, biofilms were treated with associations of 600 μmol L?1 curcumin combined or not with 1% EDTA and 37.5 or 75 J cm?2 LED (455 nm). The vitality was determined by a confocal laser scanning microscopy (CLSM) after staining biofilms with a mixture of 2.5 g L?1 fluorescein diacetate and 0.25 g L?1 ethidium bromide. Statistical analysis was conducted by Kruskal-Wallis and post hoc Dunn’s test (P < 0.05). Three treatments were able to reduce the vitality of overall biofilms: curcumin + 75 J cm?2 LED, curcumin-EDTA + 37.5 J cm?2 LED, and curcumin-EDTA + 75 J cm?2 LED. Also, the vitality of inner layers of biofilms was significantly reduced only after the combination of aPDT with EDTA. Therefore, the association of curcumin and EDTA improved the antimicrobial effect of aPDT on dentin caries microcosms, considering the application of lower light densities and deeper layers of biofilms.
关键词： Curcumin,Biofilm,Ethylenediaminetetraacetic acid,Dental caries,Photochemotherapy
更新于2025-09-23 15:23:52
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Phenanthroline-Derivative Functionalized Carbon Dots for Highly Selective and Sensitive Detection of Cu2+ and S2? and Imaging inside Live Cells
摘要： Developing effective methods for the instant detection of Cu2+ and S2? is highly desired in the biological and environmental fields. Herein, a novel fluorescent nanoprobe was elaborately designed and synthesized by grafting a phenanthroline derivative onto the surface of carbon dots (CDs). The obtained functionalized CDs (FCDs) exhibited blue fluorescence (FL) with excellent photostability and possessed a mean diameter around 4 nm. Cu2+ can be selectively captured by the phenanthroline group of FCDs to generate an absorptive complex in situ, leading to obvious quenching of the FCDs’ FL signal through an inner filter effect. Furthermore, the FL of the FCD–Cu2+ can be effectively recovered by S2? anions due to the release of FCDs from the FCD–Cu2+ complex owing to the formation of stable CuS (Ksp = 1.27 × 10?36) between S2? and Cu2+. The detection limits of the FCDs were determined to be 40.1 nM and 88.9 nM for Cu2+ and S2?, respectively. Moreover, this nanoprobe can also be used for the imaging of intracellular Cu2+ and S2?, which shows strong application prospects in the field of biology.
关键词： carbon dots,fluorescent nanoprobe,(2,3-f)-pyrazino(1,10)phenanthroline-2,3-dicarboxylic acid,Cu2+,S2?
更新于2025-09-23 15:23:52
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Crystal Structure and Luminescence of a Novel Binuclear Zinc(II) Complex with Di-2-Pyridylamine And 4,4′-Sulfonyldibenzoate
摘要： A binuclear Zn(II) complex [Zn2(SDBA)2(DPA)2?2H2O] (1) (DPA = di-2-pyridylamine, H2SDBA = 4,4′-sulfonyldibenzoic acid) is synthesized and characterized using single crystal X-ray diffraction, IR spectroscopy, and elemental analysis. The single crystal X-ray diffraction analysis reveals that complex 1 is a binuclear zinc(II) complex. The binuclear molecules are further connected by three types of N–H?O, C–H?O, and O–H?O hydrogen bonds, generating a three-dimensional supramolecular structure. Meanwhile, S–O?π interactions further consolidate the three-dimensional supramolecular framework of 1. In addition, the thermal stability and luminescent properties of the title complex are briefly investigated. The luminescence measurements reveal that complex 1 exhibits fluorescent emission in the solid state at room temperature.
关键词： luminescence,4′-sulfonyldibenzoic acid,crystal structure,4,Zn(II) complex,di-2-pyridylamine
更新于2025-09-23 15:23:52
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Synthesis, Crystal Structure and Fluorescent Property of a Onedimensional Coordination Polymer Constructed By 1,3-Bis(1,2,4-Triazol-1-Ylmethyl)- Benzene And 4,4′-Oxydiphthalic Acid
摘要： A one-dimensional Cd(II) complex [Cd(H3ODPT)2(MBTZ)2?2H2O]n (1) (MBTZ = 1,3-bis(1,2,4-triazol-1-yl-methyl)benzene, H4ODPT = 4,4′-oxydiphthalic acid) is synthesized and characterized using single crystal X-ray diffraction, IR spectroscopy, and elemental analysis. Single crystal X-ray diffraction analysis reveals that complex 1 is a one-dimensional double chain polymer containing 24-membered rings with MBTZ ligands as the bridges arranged parallel to the b crystal direction, while the singly deprotonated H4ODPT ligands are extended on both sides of such double chains. In addition, the luminescence measurements reveal that complex 1 exhibits strong fluorescent emission in the solid state at room temperature.
关键词： 4,4′-oxydiphthalic acid,1,3-bis(1,2,4-triazol-1-ylmethyl)benzene,fluorescent property,Cd(II) complex,crystal structure
更新于2025-09-23 15:23:52
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Photocatalytic degradation of phenol by LaFeO3 nanocrystalline synthesized by gel combustion method via citric acid route
摘要： Focusing on the photocatalytic degradation of phenol under visible light, the synthesized lanthanum orthoferrites (LaFeO3) by gel combustion method using citric acid as sacrificial agent were investigated. With the highest reaction temperature of 200 °C, the physicochemical properties of synthesized samples were characterized by X-Ray diffraction (XRD) analysis, Brunauer–Emmet–Teller (BET), and Energy Dispersive X-Ray spectroscopy (EDS). On the other hand, UV–Vis spectroscopy analysis was carried out to determine the phenol photodegradation activities and mechanism. The results suggested the well-defined LaFeO3 nanocrystals with specific area of 28 m2 g?1 were successfully synthesized. Besides that, variations in operating parameters such as pH, catalyst dosage and initial concentration of phenol in synthetic wastewater were also examined. In conclusion, LaFeO3 nanocrystalline exhibited an exceptional photocatalytic activity for phenol degradation, thus providing a perfect alternative for pharmaceutical wastewater treatment.
关键词： Citric acid,Photocatalytic activity,Lanthanum orthoferrite,Phenol,Gel combustion
更新于2025-09-23 15:23:52
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Spectroscopic and Theoretical Studies of Dual Fluorescence in 2-Hydroxy-N-(2-phenylethyl)benzamide Induced by ESIPT Process – Solvent Effects
摘要： This work discusses the theoretical ([TD]DFT) and spectroscopic investigation into 2-Hydroxy-N-(2-phenylethyl)benzamide (SAL3) and its physiochemical behaviour in the selected organic solvents. The compound demonstrated a dual fluorescence effect in alcoholic solutions (methanol, ethanol, isopropanol), while in acetonitrile (ACN), dimethylsulfoxide (DMSO) and non-polar solvents (n-Hexane, n-Heptane, chloroform) only a single emission maximum was observed. The noticeable shortening of average fluorescence lifetime, the employed detailed analysis of solvatochromic shifts of absorption spectra in the function of polarizability related to a change in the induction polarization of the environment and, above all, the performed quantum-mechanical calculations [TD] DFT with a detailed analysis of excited states, clearly indicate a connection between the observed fluorescence effects and processes related to changes in the system’s structure in the excited state. Based on these experimental and theoretical studies, it has been proposed that the environment (solvent) polarity-induced dual fluorescence effect in SAL3 is related to the Excited-State Intramolecular Proton Transfer (ESIPT) process. Also, the quantum-mechanic studies [TD] DFT point to the specific conformation of SAL3 molecule characteristic of dual fluorescence emission.
关键词： dual fluorescence effect,salicylic acid derivatives,[TD] DFT calculations,molecular spectroscopy,H-bonds
更新于2025-09-23 15:23:52
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High acetic acid sensing performance of Mg-doped ZnO/rGO nanocomposites
摘要： Mg-doped ZnO/reduced graphene oxide (rGO) nanocomposites were synthesized using a facile and cost-effective sol-gel procedure to detect acetic acid vapor. Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy, and photoluminescence (PL) analysis were utilized to characterize morphologies, compositions of the nanocomposites, and optical properties of the synthesized nanostructures. The gas sensing measurements of spin-coated Mg-doped ZnO/rGO thin films were carried out for a temperature range of 150–350 oC at various acetic acid vapour concentrations. It was found that the Mg-doped sample with 20 wt. %/v of GO solution concentration exhibited the response/recovery time of 60 s/35 s with the best response of ~200% for 100 ppm of acetic acid at 250 oC.
关键词： Mg-doped ZnO/rGO,Gas sensor,Acetic acid,Nanoparticles
更新于2025-09-23 15:23:52
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Mass Production of High-Purity Semiconducting Carbon Nanotubes by Hydrochloric Acid-assisted Gel Chromatography
摘要： Mass production of high-purity semiconducting single-wall carbon nanotubes (s-SWCNTs) is critical for their application in the electronic and optoelectronic devices. Here we reported a method for the high-efficiency separation of high-purity s-SWCNTs with the acid-assisted gel chromatography, in which hydrochloric acid (HCl) was used to selectively oxidize metallic SWCNTs (m-SWCNTs) and enhance the difference in the interaction of metallic and semiconducting nanotubes with gel. Specifically, the concentration of HCl in the eluent was gradually increased to elute the carbon nanotubes adsorbed in the gel column step by step. The m-SWCNTs were firstly eluted at a low HCl concentration, and high-purity s-SWCNTs were selectively eluted at a higher HCl concentration. The final residues containing a relatively high content of m-SWCNTs and amorphous carbon impurities were left in the gel columns. Optical and electrical characterizations confirmed that the purity of the s-SWCNTs extracted from various raw SWCNT materials, especially CoMoCAT (7, 6), was improved greatly. Moreover, multiple single-chirality SWCNTs were firstly separated from the purified semiconducting CoMoCAT (7, 6) nanotubes. Our present work provides a simple and controllable way for the mass separation of high-purity s-SWCNTs and single-chirality species, which would accelerate their application in the field of electronics, optoelectronics and bio-imaging.
关键词： hydrochloric acid,separation,gel chromatography,Semiconducting carbon nanotubes,single-chirality
更新于2025-09-23 15:23:52
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Battery lifetime enhancement via smart hybrid energy storage plug-in module in standalone photovoltaic power system
摘要： Standalone photovoltaic power system is one of the feasible solutions in rural electri?cation. However, due to the intermittent nature of solar energy and signi?cant demand variations due to small load size, energy storage devices are needed to ensure power quality and reliability. Lead-acid battery bank has been widely used in such systems to act as the intermediate bu?er to compensate the power mismatch between generation and demand, despite the poor lifetime characteristics and relatively short service life compared to other energy storage devices. Most charge controllers only provide basic battery charging functionality and prevent the battery bank from overcharging and deep-discharging. While other notable aging factors such as frequent charge-discharge transition, high C-rate and surge power are often neglected. This paper presents a smart hybrid energy storage plug-in module that aims to enhance the service life of Lead-acid battery in standalone photovoltaic-battery power systems by mitigating life-limiting factors such as current ?uctuations and surge current. This module is designed as a plug-in module that can be adopted directly in existing infrastructure in installed standalone PV-battery power system. The e?ectiveness of the proposed plug-in module in mitigating battery stresses is simulated in Matlab Simulink with actual solar irradiance data and estimated load pro?le for a rural community in Sarawak Malaysia. The simulation results are validated experimentally with the scaled-down photovoltaic-battery power system. The e?ectiveness in mitigating battery stress is quantitatively evaluated with battery health cost function, while the reduction in overall battery cost is analyzed and discussed.
关键词： Renewable energy,Hybrid energy storage system,Photovoltaic,Supercapacitor,Lead-acid battery,Li-ion battery
更新于2025-09-23 15:23:52