title: Biocompatible phosphonic acid-functionalized silica nanoparticles for sensitive detection of hypoxanthine in real samples.
abstract: A novel hypoxanthine biosensor fabricated by immobilizing the xanthine oxidase (XOD) onto the phosphonic acid-functionalized silica (SiO2-P) film on the surface of glassy carbon electrode (GCE) was designed and constructed in this work. A biomimetic platform was designed with the phosphonic acid-functionalized silica nanoparticles (SiO2-P NPs) synthesized by the method of reverse microemulsion and electrostatic binding. In such a platform, XOD was selected as model protein to fabricate hypoxanthine biosensor based on SiO2-P NPs. The nanocomposite was characterized with transmission electron microscopy (TEM), energy dispersive X-ray spectrometer (EDS) and electrochemical impedance spectroscopy (EIS). Based on the advantageous functions of SiO2-P NPs, the entrapped XOD could preserve its bioactivity and exhibited an excellent electrochemical behavior with a formal potential of -0.37 V in phosphate buffer solution (PBS, pH=7). Response studies to hypoxanthine were carried out using current-time response curve. The biosensor exhibited a wide linear response ranging from 1.00×10(-6) to 2.61×10(-4) M. The detection limit of 2.33×10(-7) M at a signal-to-noise ratio of 3 was lower than that most reported previously. In addition, the electrode modified with XOD/(SiO2-P NPs) film also had a strong anti-interference ability in the presence of uric acid (UA) and ascorbic acid (AA). The assay results of hypoxanthine in fish samples were in a good agreement with the reference values.
authors.affiliation: Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Shanshan
authors.initials: S
authors.lastname: Chen
authors.forename: Xianzheng
authors.initials: X
authors.lastname: Zhao
authors.forename: Yuhang
authors.initials: Y
authors.lastname: Ye
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Qinshu
authors.initials: Q
authors.lastname: Zhu
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhao
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Huang
authors.forename: Jian
authors.initials: J
authors.lastname: Shen
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry; D001672:Biocompatible Materials; D015374:Biosensing Techniques; D002244:Carbon; D002347:Carps / Q000378:metabolism*; D055664:Electrochemical Techniques; D004566:Electrodes; D004800:Enzymes, Immobilized; D006801:Humans; D019271:Hypoxanthine / Q000032:analysis* / Q000737:chemistry; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010757:Phosphorous Acids / Q000737:chemistry*; D059629:Signal-To-Noise Ratio; D012822:Silicon Dioxide / Q000737:chemistry*; D014527:Uric Acid / Q000737:chemistry; D014969:Xanthine Oxidase / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004800:Enzymes, Immobilized; D010757:Phosphorous Acids; C570063:phosphonic acid; D014527:Uric Acid; D019271:Hypoxanthine; D002244:Carbon; D012822:Silicon Dioxide; D014969:Xanthine Oxidase; D001205:Ascorbic Acid
keywords: Biomimetic; Biosensor; Phosphonic acid-functionalized; Silica; Xanthine oxidase