Rahman M M, Shiddiky Muhammad J A, Rahman Md Aminur, Shim Yoon-Bo
Department of Chemistry and Center for Innovative BioPhysio Sensor Technology, Keumjeong-ku, Pusan National University, Pusan 609-735, Republic of Korea.
Anal Biochem. 2009 Jan 1;384(1):159-65. doi: 10.1016/j.ab.2008.09.030. Epub 2008 Sep 25.
An amperometric lactate biosensor was developed based on a conducting polymer, poly-5,2'-5',2''-terthiophene-3'-carboxylic acid (pTTCA), and multiwall carbon nanotube (MWNT) composite on a gold electrode. Lactate dehydrogenase (LDH) and the oxidized form of nicotinamide adenine dinucleotide (NAD(+)) were subsequently immobilized onto the pTTCA/MWNT composite film. The modified electrode was characterized by quartz crystal microbalance (QCM), scanning electron microscopy (SEM), and electrochemical experiments. The detection signal was amplified by the pTTCA/MWNT assembly onto which a sufficient amount of enzyme was immobilized and stabilized by the covalent bond formation between the amine groups of enzyme and the carboxylic acid groups of the pTTCA/MWNT film. Experimental parameters affecting the sensor responses, such as applied potential, pH, and temperature, were assessed and optimized. Analytical performances and dynamic ranges of the sensor were determined, and the results showed that the sensitivity, stability, and reproducibility of the sensor improved significantly using pTTCA/MWNT composite film. The calibration plot was linear (r(2)=0.9995) over the range of 5 to 90 microM. The sensitivity was approximately 0.0106 microA/microM, with a detection limit of 1 microM, based on a signal/noise ratio of 3. The applicability of the sensor for the analysis of l-lactate concentration in commercial milk and human serum samples was demonstrated successfully.
基于导电聚合物聚-5,2'-5',2''-三联噻吩-3'-羧酸（pTTCA）和多壁碳纳米管（MWNT）在金电极上的复合材料，开发了一种安培型乳酸生物传感器。随后将乳酸脱氢酶（LDH）和烟酰胺腺嘌呤二核苷酸的氧化形式（NAD(+)）固定在pTTCA/MWNT复合膜上。通过石英晶体微天平（QCM）、扫描电子显微镜（SEM）和电化学实验对修饰电极进行了表征。检测信号通过pTTCA/MWNT组装体进行放大，在该组装体上，通过酶的胺基与pTTCA/MWNT膜的羧酸基团之间形成共价键，固定并稳定了足够量的酶。评估并优化了影响传感器响应的实验参数，如施加电位、pH值和温度。测定了传感器的分析性能和动态范围，结果表明，使用pTTCA/MWNT复合膜后，传感器的灵敏度、稳定性和重现性显著提高。校准曲线在5至90 microM范围内呈线性（r(2)=0.9995）。基于3的信噪比，灵敏度约为0.0106 microA/microM‘检测限为1 microM。成功证明了该传感器在商业牛奶和人血清样品中l-乳酸浓度分析中的适用性。
