A label-free impedimetric DNA sensing chip integrated with AC electroosmotic stirring.
AC electroosmosis (ACEO) flow and label-free electrochemical impedance spectroscopy are employed to increase the hybridization rate and specifically detect target DNA (tDNA) concentrations. A low-ionic-strength solution, 6.1μS/cm 1mM Tris (pH 9.3), was used to produce ACEO and proved the feasibility of hybridization. Adequate voltage parameters for the simultaneous ACEO driving and DNA hybridization in the 1mM Tris solution were 1.5 Vpp and 200Hz. Moreover, an electrode set with a 1:4 ring width-to-disk diameter ratio exhibited a larger ACEO velocity above the disk electrode surface to improve collecting efficiency. The ACEO-integrated DNA sensing chips could reach 90% saturation hybridization within 117s. The linear range and detection limit of the sensors was 10aM-10pM and 10aM, respectively. The label-free impedimetric DNA sensing chips with integrated ACEO stirring can perform rapid hybridization and highly-sensitive detections to specifically measure tDNA concentrations.
Department of Bio-Industrial Mechatronics Engineering, National Chung Hsing University, Taiwan, ROC. ccwu@dragon.nchu.edu.tw
Ching-Chou
CC
Wu
Dong-Jie
DJ
Yang
D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D058266:Dielectric Spectroscopy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D044085:Microfluidics / Q000295:instrumentation*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D013194:Staining and Labeling; D018511:Systems Integration
D004247:DNA