Arora Kavita, Prabhakar Nirmal, Chand Subhash, Malhotra B D
Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr KS Krishnan Marg, New Delhi, India.
Biosens Bioelectron. 2007 Dec 15;23(5):613-20. doi: 10.1016/j.bios.2007.07.010. Epub 2007 Jul 31.
Ultrasensitive DNA hybridization biosensor based on polyaniline (PANI) electrochemically deposited onto Pt disc electrode has been fabricated using biotin-avidin as indirect coupling agent to immobilize single-stranded 5'-biotin end-labeled polydeoxycytidine (BdC) probes and 5'-biotin end-labeled 35 base-long oligonucleotide probe (BdE) to detect complementary target, using both direct electrochemical oxidation of guanine and redox electroactive indicator methylene blue (MB), respectively. These polyaniline-based disc electrodes have been characterized using differential pulse voltammetry (DPV), Fourier transform infrared spectroscopy (FT-IR), impedance measurements and scanning electron microscopy (SEM) techniques, respectively. Compared to direct electrochemical oxidation of guanine, hybridization detection using MB results in the enhanced detection limit by about 100 times. These DNA immobilized PANI electrodes have hybridization response time of about 60 s.
基于电化学沉积在铂圆盘电极上的聚苯胺（PANI）构建了超灵敏DNA杂交生物传感器，该传感器使用生物素-抗生物素蛋白作为间接偶联剂，以固定5'-生物素末端标记的聚脱氧胞苷（BdC）单链探针和5'-生物素末端标记的35个碱基长的寡核苷酸探针（BdE）来检测互补靶标，分别利用鸟嘌呤的直接电化学氧化和氧化还原电活性指示剂亚甲基蓝（MB）。这些基于聚苯胺的圆盘电极分别使用差分脉冲伏安法（DPV）、傅里叶变换红外光谱（FT-IR）、阻抗测量和扫描电子显微镜（SEM）技术进行了表征。与鸟嘌呤的直接电化学氧化相比，使用MB进行杂交检测可使检测限提高约100倍。这些固定有DNA的聚苯胺电极的杂交响应时间约为60秒。
