Uricase-adsorbed carbon-felt reactor coupled with a peroxidase-modified carbon-felt-based H2O2 detector for highly sensitive amperometric flow determination of uric acid

School of Chemical Engineering, University of Science and Technology LiaoNing, 185 Qianshan Middle Road, High-tech Zone, Anshan, LiaoNing 114501, China.
Journal of pharmaceutical and biomedical analysis (Impact Factor: 2.98). 08/2011; 57(1):125-32. DOI: 10.1016/j.jpba.2011.08.021
Source: PubMed

ABSTRACT Uricase (urate oxidase, UOx) was adsorbed onto a porous carbon-felt (CF) surface and the resulting UOx-adsorbed CF (UOx-CF) was successfully used as a column-type enzyme reactor coupled with a peroxidase-adsorbed CF-based bioelectrocatalytic H(2)O(2) flow-detector to fabricate a flow-amperometric biosensor for uric acid. In this flow-biosensor system, H(2)O(2) produced in the UOx-CF reactor was cathodically detected by horseradish peroxidase (HRP) and a thionine (Th)-coadsorbed CF (HRP/Th-CF)-based bioelectrocatalytic flow-detector at -0.05V vs. Ag/AgCl. Various adsorption conditions of the UOx (i.e., pH of the adsorption solution, type and concentration of the buffer used as the adsorption solvent, UOx concentration and adsorption time) and the operational conditions of the UOx-CF and HRP/Th-CF-coupled flow-biosensor (i.e., carrier flow rate and carrier pH) were optimized to obtain highly sensitive, selective and stable peak current responses to uric acid. The analytical performance of the UOx-CF and HRP/Th-CF-coupled flow biosensor for uric acid was as follows: sensitivity, 0.25μA/uM; linear range, 0.3-20μM; lower detection limit, 0.18μM; and sample throughput, ca. 30-90 samples/h. The resulting amperometric flow-biosensor for uric acid allowed the determination of uric acid in highly diluted body fluids (human serum and urine), and the analytical results obtained by the present biosensor were in fairly good agreement with those obtained by conventional enzyme-based spectrophotometry.

1 Follower
8 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: The enzymatic spectrophotometric analysis of uric acid based on BSA-stabilized Au nanoclusters (Au NCs) as peroxidase mimetics was first developed. Compared with natural enzyme horseradish peroxidase (HRP), which was used widely to detect H2O2 generated by uric acid, the BSA-stabilized Au NCs as peroxidase mimetics are easy to prepare, low cost, and stable. Kinetic analysis indicates that the BSA-stabilized Au NCs have even higher catalytic activity than HRP. Under the optimum conditions, the detection limit for uric acid is 3.6 x 10(-7) mol L-1. The feasibility of the developed method for uric acid analysis in human serum was confirmed.
    Spectroscopy Letters 10/2012; 45(7):511-519. DOI:10.1080/00387010.2011.649440 · 0.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we fabricate a sensitive and stable amperometric UA amperometric biosensor using nanobiocomposite derived from thionine modified graphene oxide in this study. A simple wet-chemical strategy for synthesis of thionine-graphene oxide hybrid nanosheets (T-GOs) through π-π stacking has been demonstrated. Various techniques, such as UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and electrochemistry have been utilized to characterize the formation of the T-GOs. Due to the synergistic effect between thionine and graphene oxide, the nanosheets exhibited excellent performance toward H(2)O(2) reduction. The incorporation of thionine onto graphene oxide surface resulted in more than a twice increase in the amperometric response to H(2)O(2) of the thionine modified electrode. The as-formed T-GOs also served as a biocompatible matrix for enzyme assembly and a mediator to facilitate the electron transfer between the enzyme and the electrode. Using UOx as a model system, we have developed a simple and effective sensing platform for assay of uric acid at physiological levels. UA has been successfully detected at -0.1V without any interference due to other electroactive compounds at physiological levels of glucose (5mM), ascorbic acid (0.1mM), noradrenalin (0.1mM), and dopamine (0.1mM). The response displays a good linear range from 0.02 to 4.5mM with detection limit 7μM. The application of this modified electrode in blood and urine UA exhibited a good performance. The robust and advanced hybrid materials might hold great promise in biosensing, energy conversion, and biomedical and electronic systems.
    Analytica chimica acta 01/2013; 761:84-91. DOI:10.1016/j.aca.2012.11.057 · 4.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this work, we have developed a novel approach that fabricating carbon nanoelectrode ensembles (carbon NEEs) with the pores of 50–120 nm in radii by self-assembling a copolymer [poly(acrylonitrile-co-acrylic acid)]. Only conventional, inexpensive electrochemical instrument is required for this procedure, which is simple and fast. The electrochemical behavior of AA and UA at this carbon NEEs has been studied by CV and differential pulse voltammetry (DPV). The carbon NEEs can suppress the response of ascorbic acid (AA) drastically and resolve the overlapping voltammetric response of uric acid (UA) and AA into two well-defined peaks with a large anodic peak difference (ΔEpa) of about 330 mV. Meanwhile, the carbon-based electrodes have the weak absorption and fast electron transfer. The reaction of UA and AA take place in the different micro-environment in the presence of the carboxylic functional groups in the nanopores. The sensor offers the peak current that was linearly dependent on the UA concentration in the range from 5.0 × 10−7 mol/L to 5.0 × 10−5 mol/L at neutral pH (PBS, pH 6.86) with a correlation coefficient of 0.998, and the detection limit was 1.0 × 10−7 mol/L (S/N = 3). The carbon NEEs shows excellent sensitivity and selectivity and has been used for the determination of UA in real serum and urine samples with satisfied results.
    Sensors and Actuators B Chemical 05/2013; 181:194–201. DOI:10.1016/j.snb.2013.01.087 · 4.10 Impact Factor
Show more