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oe1(光电查) - 科学论文

9 条数据
?? 中文(中国)
  • 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

  • In-situ synthesis of gold nanocrystals anchored graphene oxide and its application in biosensor and chemical sensor

    摘要: This research demonstrated the development of graphene oxide (GO)-gold nanocrystals (AuNCs) composite-modified glassy carbon electrode (GCE) for the sensitive detection of dopamine (DA), uric acid (UA), and 4-aminophenol (4-AP). The GO was synthesized by modified Hummer’s method, which was utilized to prepare GO-AuNCs composites by in situ synthesis method using sodium L(-) malate as a reducing agent. Morphological, X-ray diffraction, and spectral analysis revealed the homogeneous formation of AuNCs with high crystallinity and purity on the GO surface and the sizes of the NCs were decreased with increasing the concentrations of sodium L(-) malate. The optimal GCE/GO-AuNCs sensor exhibited excellent electrocatalytic activity towards the oxidation of DA, UA, and 4-AP. The sensor showed interference-free and selective detection of DA and UA with sensitivities of ca. 30.3 and 17.28 μA/cm2/μM, respectively, and detection limits of ca. 28 and 50 nM, respectively, with wider dynamic ranges, measured by differential pulse voltammetry (DPV) technique. Whereas, it displayed a sensitivity and detection limit of ca. 5.70 μA/cm2/mM and 0.017 nM, respectively, for the detection of 4-AP, using current density (J)-voltage (V) measurement method. The sensor also revealed excellent stability, reproducibility, and recoveries of DA, UA, and 4-AP in real samples.

    关键词: dopamine,4-aminophenol,Graphene Oxide-Au nanocrystals,uric acid,electrochemical detection

    更新于2025-09-23 15:22:29

  • S, N-doped carbon quantum dots enhanced Luminol-Mn(IV) chemiluminescence reaction for detection of uric acid in biological fluids

    摘要: Herein, S, N doped carbon quantum dots (S, N- CQDs) were prepared by a simple hydrothermal method and characterized by transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared (FTIR) analysis. The influence of as-prepared CQDs was studied on the luminol- Mn(IV) CL reaction. The results indicated that S, N-CQDs remarkably increase the CL intensity of this reaction (about 13 fold). Furthermore, it was found that the CL intensity of S,N-CQDs–luminol-Mn(IV) system was significantly declined by uric acid. We exploited the amplified CL system to design a novel probe for the detection of uric acid. The CL intensity of S,N-CQDs–luminol-Mn(IV) reaction was proportional to the logarithm of uric acid concentration in the range of 0.05 to 1.5 μM, with a limit of detection of 17 nM. Based on these results, a sensitive and straightforward CL method was developed for the analysis of uric acid in biological fluids with satisfactory results.

    关键词: Uric acid,sulfur-nitrogen doped carbon quantum dots,Chemiluminescence,Mn (IV)

    更新于2025-09-23 15:19:57

  • A luminescent terbium metal-organic framework for highly sensitive and selective detection of uric acid in aqueous media

    摘要: As the final product of purine metabolism, uric acid (UA) existing in urine and serum plays an important role in the body's metabolism, immunity and other functions. However, it is still difficult to sense UA in practice. Herein, a new terbium metal–organic framework (Me2NH2)2[Tb2(L)2]·(H2O)6 (ZJU-158-Tb, ZJU=Zhejiang University, L= 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid )for luminescent sensing of UA was designed and synthesized. It exhibits highly sensitive and selective detection to UA in aqueous solutions with a quite low detection limit of 7 nM by a luminescence turn-down phenomenon. Furthermore, the practical test papers made by ZJU-158-Tb possess fast monitoring ability for abnormal UA levels in artificial urine and serum through distinct color change, which could be even distinguished by the naked eye.

    关键词: uric acid,Metal-organic frameworks,test paper.,fluorescence sensor

    更新于2025-09-19 17:15:36

  • Simultaneous determination of ascorbic acid, dopamine, and uric acid using graphene quantum dots/ionic liquid modified screen-printed carbon electrode

    摘要: In this work, graphene quantum dots (GQDs) and ionic liquid (IL) modified screen-printed carbon electrode (GQDs/IL-SPCE) were introduced for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). GQDs were synthesized by directly pyrolyzing citric acid and then dropped onto the surface of IL-SPCE, which was prepared by screen-printing the mixture of IL and carbon ink on a portable substrate. UV-Vis spectrophotometry, fluorescence spectrophotometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to characterize the synthesized GQDs and the modified electrodes. The GQDs/IL-SPCE exhibited excellent electrocatalytic activity for the oxidation of AA, DA, and UA in the mixture solution. Moreover, the anodic peak responses of these three analytes were also resolved into three well-defined peaks. Under the optimized conditions, the linear response ranges for AA, DA, and UA were 25 - 400 μM, 0.2 - 10 μM, and 0.5 - 20 μM, respectively, with low detection limits (σ/N = 3) of 6.64 μM, 0.06 μM, and 0.03 μM, respectively. The proposed sensor exhibited high sensitivity, low cost and successfully applied for the simultaneous detection of AA, DA, and UA in pharmaceutical products and biological samples.

    关键词: Graphene quantum dots,Uric acid,Dopamine,Screen-printed carbon electrode,Ionic liquid,Ascorbic acid

    更新于2025-09-19 17:13:59

  • DC-biased optofluidic biolaser for uric acid detection

    摘要: Optofluidic biolaser is an emerging technology for chemical and biomedical sensing. However, the sensitivity of optofluidic laser is still limited by the laser threshold condition. In this paper we report a DC-biased optofluidic biolaser for uric acid (UA) detection. Inside a Fabry-Perot laser cavity, a coupled enzyme reaction was employed to transform the detection of UA into the detection of analyte-converted hydrogen peroxide (H2O2). The fluorescent product of the enzyme-catalyzed reaction, resorufin, was employed as gain medium for optofluidic lasing. An optimized concentration of H2O2 was pre-added as a DC bias to counterbalance the requirement of high analyte concentration for lasing. UA detection with a limit of detection of 3.63 μM was achieved with a low sample volume as small as 10 μl. This work provides a sensitive technology using optofluidic biolaser for the detection of substance in human body fluids that can be converted into H2O2.

    关键词: Optofluidic laser,uric acid,enzyme catalytic reaction,optical biosensing

    更新于2025-09-16 10:30:52

  • One-step hydrothermal synthesis of silver-doped carbon quantum dots for highly selective detection of uric acid

    摘要: In this paper, a simple and convenient fluorescence method for detection of uric acid (UA) based on Ag-doped carbon quantum dots (Ag-CQDs) is developed. The Ag-CQDs contain Ag species could bond with UA, which promoted the electron and/or energy transfer and produced high quenching extent. Thus, the fluorescence intensity of Ag-CQDs decreased in the presence of UA. Under the optimal condition, the UA sensor exhibited a linear response in the range of 0.005-100 μM with a detection limit of 0.35 nM (S/N=3). Ag-CQDs demonstrated high sensitivity and rapid response to UA over a wide range of concentration indicating their great potential as a fluorescent probe for chemical sensing. Moreover, this method has successfully applied to detect UA in human urine samples.

    关键词: silver,doping,carbon quantum dots,uric acid,fluorescence

    更新于2025-09-11 14:15:04

  • Investigating the electrochemical behaviour and detection of uric acid on ITO electrodes modified with differently doped N-graphene films

    摘要: Sensitive and selective electrochemical sensors based on indium-doped tin oxide electrodes (ITO) modified with differently nitrogen-doped graphene (NGr) films were successfully developed for the individual and simultaneous determination of uric acid (UA) in the presence of ascorbic acid (AA). The influence of the contents of various N-configurations on the detection of UA on the NGr/ITO based sensors is herein reported for the first time. The contents of various N-configurations on the NGr/ITO electrodes displayed varying promotional effects of the electro-oxidation of UA; attributed to the unique properties of the NGr films arising from the N-configurations. In particular, three N-doped materials prepared with varying amount of graphitic-N, pyrrolic-N, and pyridinic-N allowed the individual detection of UA, in the presence of AA, in the concentration range from 2-320 μM with the detection limits of 0.043 μM to 0.19 μM. Finally, the NGr/ITO-based sensors exhibited successful simultaneous detection of UA and AA, depicting detection limits of 0.051 - 0.19 μM and 0.93 – 5.1 μM within the concentration ranges of 6 - 280 μM and 8 – 800 μM, for the detection of UA and AA, respectively. The study provided insight into an understanding as to how the different contents of N-configurations influenced the electrocatalytic activity of NGr/ITO electrodes for the individual and simultaneous detection of uric acid.

    关键词: nitrogen-doped graphene,uric acid,indium-doped tin oxide,ascorbic acid,electrochemical sensors

    更新于2025-09-09 09:28:46

  • A comprehensive review on thin film-based nano-biosensor for uric acid determination: arthritis diagnosis

    摘要: This article aims to provide a survey on the development of thin film-based nano-biosensor over the decade, which includes sensing principles, electrode types and various thin film matrices. The theoretical and experimental results suggest that the thin film-based sensor are suitable for highly sensitive detection of low concentration bio molecules and can be used for early diagnosis and screening of arthritis, kidney diseases and other cardiovascular diseases. This review concludes that enzyme immobilisation and surface functionalisation methods were used to increase sensitivity of the biosensor and new combination of polymer nano-composites with metal oxide thin films results in increased efficiency due to its high biocompatibility.

    关键词: nanomaterials,enzymes,thin films,uric acid,immobilisation,biocompatibility

    更新于2025-09-09 09:28:46