Department of Biochemistry, M D University, Rohtak, India.
Int J Biol Macromol. 2012 Jan 1;50(1):112-8. doi: 10.1016/j.ijbiomac.2011.10.002. Epub 2011 Oct 15.
A chitosan-glutaraldehyde crosslinked uricase was immobilized onto Prussian blue nanoparticles (PBNPs) absorbed onto carboxylated multiwalled carbon nanotube (c-MWCNT) and polyaniline (PANI) layer, electrochemically deposited on the surface of Au electrode. The nanohybrid-uricase electrode was characterized by scanning electron microscopic (SEM), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry. An amperometric uric acid biosensor was fabricated using uricase/c-MWCNT/PBNPs/Au electrode as working electrode, Ag/AgCl as standard and Pt wire as auxiliary electrode connected through a potentiostat. The biosensor showed optimum response within 4s at pH 7.5 and 40°C, when operated at 0.4V vs. Ag/AgCl. The linear working range for uric acid was 0.005-0.8 mM, with a detection limit of 5 μM. The sensor was evaluated with 96% recovery of added uric acid in sera and 4.6 and 5.4% within and between batch of coefficient of variation respectively and a good correlation (r=0.99) with standard enzymic colorimetric method. This sensor measured uric acid in real serum samples. The sensor lost only 37% of its initial activity after its 400 uses over a period of 7 months, when stored at 4°C.
壳聚糖-戊二醛交联尿酸酶固定在普鲁士蓝纳米粒子（PBNPs）上，PBNPs 被吸附在羧基化多壁碳纳米管（c-MWCNT）和聚苯胺（PANI）层上，并通过电化学沉积在 Au 电极表面。纳米杂化尿酸酶电极通过扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和循环伏安法进行了表征。使用尿酸酶/c-MWCNT/PBNPs/Au 电极作为工作电极，Ag/AgCl 作为参比电极，Pt 丝作为辅助电极，通过电位计连接，制备了安培型尿酸生物传感器。在 pH 7.5 和 40°C 下，当在 0.4V 相对于 Ag/AgCl 时，生物传感器在 4s 内显示出最佳响应。尿酸的线性工作范围为 0.005-0.8mM，检测限为 5μM。该传感器在血清中添加尿酸的回收率为 96%，批内和批间的变异系数分别为 4.6%和 5.4%，与标准酶比色法具有良好的相关性（r=0.99）。该传感器可测量真实血清样品中的尿酸。在 7 个月的时间内，传感器在 4°C 下储存时，经过 400 次使用后，其初始活性仅损失了 37%。
