The nanoparticles of xanthine oxidase (XODNPs) were prepared by desolvation method and characterized by transmission electron microscopy(TEM) and Fourier transform Infra-red spectroscopy(FTIR). These XODNPs were immobilized directly onto surface of Au electrode via covalent bond. An improved amperometric xanthine biosensor was fabricated using XODNPs modified Au electrode, as working electrode (WE), Ag/AgCl as reference electrode and Pt wire as auxiliary electrode connected through potentiostat.The biosensor showed optimum current at 0.25 V within 5 s, at pH 7.0 and 35 °C.The working range of biosensor was 0.01–1.0 μM with a limit of detection of 0.01 μM.The % recovery of added xanthine (1 and 5 μM) was 94.1 ± 0.2 and 94.8 ± 0.31 respectively. Within and between batch coefficient of variation (CV) were <2% & < 2.5% respectively. A good correlation (R² = 0.996) was obtained between xanthine contents in various fish meat,as measured by the present biosensor and the standard bienzymic colorimetric method. The biosensor was employed for measuring xanthine level in fish meat at different stages of storage to test its freshness. The XODNPs modified Au electrode was stored dry at 4 °C for 2 months.

采用去溶剂法制备黄嘌呤氧化酶纳米粒（XODNPs），并通过透射电子显微镜（TEM）和傅里叶变换红外光谱（FTIR）进行表征。这些 XODNPs 通过共价键直接固定在 Au 电极的表面上。使用 XODNPs 修饰的 Au 电极作为工作电极 (WE)、Ag/AgCl 作为参比电极和 Pt 线作为通过恒电位仪连接的辅助电极制造了一种改进的电流型黄嘌呤生物传感器。该生物传感器在 5 秒内显示出最佳电流为 0.25 V，在 pH 值下7.0 和 35 °C。生物传感器的工作范围为 0.01–1.0 μM，检测限为 0.01 μM。添加的黄嘌呤（1 μM 和 5 μM）的回收率分别为 94.1 ± 0.2 和 94.8 ± 0.31。批次内和批次间的变异系数 (CV) 分别为 <2% 和 < 2.5%。²  = 0.996) 在各种鱼肉中的黄嘌呤含量之间获得，通过本生物传感器和标准双酶比色法测量。该生物传感器用于测量不同储存阶段鱼肉中的黄嘌呤水平，以测试其新鲜度。XODNPs 修饰的 Au 电极在 4°C 下干燥储存 2 个月。