Arora Kavita, Sumana G, Saxena Vibha, Gupta R K, Gupta S K, Yakhmi J V, Pandey M K, Chand Subhash, Malhotra B D
Biomolecular Electronics & Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012, India.
Anal Chim Acta. 2007 Jun 26;594(1):17-23. doi: 10.1016/j.aca.2007.04.068. Epub 2007 May 16.
Uricase has been covalently immobilized using glutaraldehyde as cross-linker onto electrochemically synthesized polyaniline (PANI) films. These PANI-uricase electrodes have been characterized using spectroscopic, cyclic voltammetry and impedance measurements. The morphology and covalent linkage of uricase lead to high enzyme loading and better shelf life. The value of the Michaelis-Menton constant obtained as 5.1x10(-3) mM L(-1) for the immobilized uricase compared to 3.4x10(-1) mM L(-1) for the free uricase enzyme, suggests enhancement in affinity and/or activity of uricase attached to PANI. The influence of pH, temperature and concentration on electrode activity were studied. The enzyme electrodes were found to retain 95% of activity after 17-18 weeks when stored at 4 degrees C. These electrodes have a response time of about 60 s and have been used to measure uric acid concentration in serum. These PANI-uricase electrodes can be used for about 30 times for electrochemical measurements while retaining about 90% of its activity indicating improved performance.
使用戊二醛作为交联剂，将尿酸酶共价固定在电化学合成的聚苯胺（PANI）薄膜上。已使用光谱法、循环伏安法和阻抗测量对这些聚苯胺-尿酸酶电极进行了表征。尿酸酶的形态和共价连接导致高酶负载量和更好的保质期。固定化尿酸酶的米氏常数为5.1×10⁻³ mM L⁻¹，而游离尿酸酶的米氏常数为3.4×10⁻¹ mM L⁻¹，这表明附着在聚苯胺上的尿酸酶的亲和力和/或活性有所增强。研究了pH、温度和浓度对电极活性的影响。发现酶电极在4℃下储存17-18周后仍保留95%的活性。这些电极的响应时间约为60秒，已用于测量血清中的尿酸浓度。这些聚苯胺-尿酸酶电极可用于约30次电化学测量，同时保留约90%的活性，表明性能有所改善。
