title: Electrochemiluminescent biosensor for hypoxanthine based on the electrically heated carbon paste electrode modified with xanthine oxidase.
abstract: A new electrochemiluminescent (ECL) biosensor based on an electrically heated carbon paste electrode (HCPE) that was surface modified by xanthine oxidase (XOD) was designed and constructed in this work. It was found that the ECL intensity of luminol could be enhanced at the surface of XOD/HCPE by adding hypoxanthine (HX) to the solution, and there was a linear relationship between the ECL intensity and the concentration of HX. On the basis of this, an ECL enzyme biosensor can thus be developed to detect HX. However, because the activity of XOD is highly dependent on temperature, the biosensor is very sensitive to the temperature of the electrode. Also, because the temperature of the electrode may also affect the diffusion and convection of the luminescent compounds near the electrode surface, a suitable temperature for XOD/HCPE has to be controlled to achieve the best ECL signal. The key feature of the designed biosensor is that the temperature of the electrode is controllable so the most suitable temperature for the enzyme reaction can be obtained. The obtained results showed that the ECL enzyme biosensor exhibited the best sensitivity at an electrode temperature of 35 degrees C for the detection of HX. The detection limit was 30-fold lower than that at room temperature (25 degrees C).
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety and Department of Chemistry, Fuzhou University, Fuzhou, Fujian, 350002, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lin
authors.forename: Jianjun
authors.initials: J
authors.lastname: Sun
authors.forename: Jinhua
authors.initials: J
authors.lastname: Chen
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
authors.forename: Yiting
authors.initials: Y
authors.lastname: Chen
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D019271:Hypoxanthine / Q000032:analysis* / Q000378:metabolism; D008163:Luminescent Measurements / Q000379:methods; D008165:Luminol / Q000737:chemistry*; D015203:Reproducibility of Results; D013696:Temperature; D014783:Viscosity; D014969:Xanthine Oxidase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004800:Enzymes, Immobilized; D019271:Hypoxanthine; D008165:Luminol; D002244:Carbon; D014969:Xanthine Oxidase