کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
220765 | 463350 | 2007 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Hybridization-induced interfacial changes detected by non-Faradaic impedimetric measurements compared to Faradaic approach Hybridization-induced interfacial changes detected by non-Faradaic impedimetric measurements compared to Faradaic approach](/preview/png/220765.png)
A biosensor for direct label-free DNA detection based on a polythiophene matrix is investigated by electrochemical impedance spectroscopy (EIS). Impedimetric experiments are performed with and without redox probe in solution. The non-Faradaic impedance measurements reveal two relaxation processes located at 50 Hz and 5 kHz, respectively. The first relaxation process, located at low frequencies, allows to detect biorecognition events by measuring the phase angle decrease, in accordance with a hindrance of the polaronic conduction. The second relaxation process, located at 5 kHz and originating from DNA modification, seems to increase with the length of the target sequence. These results suggest that this loaded support provides a platform for impedimetric detection of hybridization at high frequencies, leading to less time-consuming detection procedure. For a better understanding, results obtained in non-Faradaic mode are compared with Faradaic approach.
Journal: Journal of Electroanalytical Chemistry - Volume 610, Issue 2, 1 December 2007, Pages 227–233