An amperometric urea bisosensor based on covalent immobilization of urease on N2 incorporated diamond nanowire electrode.
N2 incorporated diamond nanowire (N-DNW) film electrochemical biosensor has utilized for the quantitative determination of urea in aqueous solution and urine sample. N-DNW electrode is wet-chemically cleaned (oxidation) by boiling in a mixture of H2SO4 and HNO3 (3:1) at 200°C for 2h to remove graphite. Urease (Urs) and glutamate dehydrogenase (GLDH) are covalently attached to the oxidized N-DNW electrode by activating the COOH group of N-DNW using ethyl(dimethylaminopropyl)carbodiimide as the coupling agent and N-hydroxysuccinimide as activator. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy data reveal that carboxylic and hydroxyl functionalized nature of N-DNW electrodes Urs-GLDH immobilized N-DNW (Urs-GLDH/N-DNW) has been successfully utilized in urea biosensor which exhibits good performance in sensitivity (6.18 μA/mg dL/cm(2)), stability (~1 month), reproducibility, lower detection limit (3.87 mg/dL) and fast response time (>10s). Urs-GLDH/N-DNW also exhibits electrochemical response when tested for different concentration of human urine in buffer solution (from 1:9 to 4:6). In addition, Urs-GLDH/N-DNW bioelectrode retains 80% of its initial enzyme activity for <1 month, when stored at 4-6°C in a refrigerator.
Department of Material Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC.
Jayakumar
J
Shalini
Department of Material Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC.
Kamatchi Jothiramalingam
KJ
Sankaran
Department of Material Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC. Electronic address: cylee@mx.nthu.edu.tw.
Chi-Young
CY
Lee
Department of Material Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC.
Nyan-Hwa
NH
Tai
Department of Physics, Tamkang University, New Taipei 251, Taiwan, ROC.
I-Nan
IN
Lin
D015374:Biosensing Techniques / Q000295:instrumentation*; D018130:Diamond / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D004867:Equipment Design; D005969:Glutamate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D057230:Limit of Detection; D053770:Nanowires / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D015203:Reproducibility of Results; D013388:Succinimides / Q000737:chemistry; D014508:Urea / Q000032:analysis / Q000652:urine*; D014510:Urease / Q000737:chemistry / Q000378:metabolism*
D004800:Enzymes, Immobilized; D013388:Succinimides; D018130:Diamond; D014508:Urea; D005969:Glutamate Dehydrogenase; D014510:Urease; C001426:N-hydroxysuccinimide; D009584:Nitrogen
Amperometry; Cyclic voltammetry; Electrochemical impedance spectrsocopy; N(2) incorporated diamond nanowire; Urea; Urs–GLDH/N-DNW