Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana 124001, India.
Anal Biochem. 2011 Dec 15;419(2):277-83. doi: 10.1016/j.ab.2011.07.032. Epub 2011 Aug 11.
A mixture of commercial creatinine amidohydrolase (CA), creatine amidinohydrolase (CI), and sarcosine oxidase (SO) was coimmobilized covalently via N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) chemistry onto carboxylated multiwalled carbon nanotube (c-MWCNT)/polyaniline (PANI) nanocomposite film electrodeposited over the surface of a platinum (Pt) electrode. A creatinine biosensor was fabricated using enzyme/c-MWCNT/PANI/Pt as working electrode, Ag/AgCl as reference electrode, and Pt wire as auxiliary electrode connected through potentiostat. The enzyme electrode was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and electrochemical impedance spectroscopy (EIS). The biosensor detected creatinine levels as low as 0.1 μM, estimated at a signal-to-noise ratio of 3, within 5s at pH 7.5 and 35°C. The optimized biosensor showed a linear response range of 10 to 750 μM creatinine with sensitivity of 40 μA/mM/cm(2). The fabricated biosensor was successfully employed for determination of creatinine in human serum. The biosensor showed only 15% loss in its initial response after 180 days when stored at 4°C.
商业肌酐 amidohydrolase（CA）、肌酸 amidinohydrolase（CI）和肌氨酸氧化酶（SO）的混合物通过 N-乙基-N'-(3-二甲基氨基丙基)碳二亚胺（EDC）和 N-羟基琥珀酰亚胺（NHS）化学共价共固定在羧基多壁碳纳米管（c-MWCNT）/聚苯胺（PANI）纳米复合材料上，该纳米复合材料通过电沉积沉积在铂（Pt）电极表面上。使用酶/c-MWCNT/PANI/Pt 作为工作电极、Ag/AgCl 作为参比电极和 Pt 丝作为辅助电极通过电势计连接来制造肌酸酐生物传感器。通过扫描电子显微镜（SEM）、傅里叶变换红外（FTIR）光谱和电化学阻抗谱（EIS）对酶电极进行了表征。该生物传感器在 pH 7.5 和 35°C 时，在 5s 内即可检测到低至 0.1μM 的肌酸酐，其信号噪声比为 3。优化后的生物传感器在 10 至 750μM 肌酸酐范围内具有线性响应，灵敏度为 40μA/mM/cm²。该生物传感器已成功用于测定人血清中的肌酸酐。当储存在 4°C 时，生物传感器在 180 天后其初始响应仅损失 15%。
