title: Electrokinetic acceleration of DNA hybridization in microsystems.
abstract: In this work, electrokinetic acceleration of DNA hybridization was investigated by different combinations of frequencies and amplitudes of actuating electric signals. Because the frequencies from low to high can induce different kinds of electrokinetic forces, i.e., electroosmotic to electrothermal forces, this work provides an in-depth investigation of electrokinetic enhanced hybridization. Concentric circular Cr/Au microelectrodes of 350 µm in diameter were fabricated on a glass substrate and probe DNA was immobilized on the electrode surface. Target DNA labeled with fluorescent dyes suspending in solution was then applied to the electrode. Different electrokinetic forces were induced by the application of different electric signals to the circular microelectrodes. Local microfluidic vortexes were generated to increase the collision efficiency between the target DNA suspending in solution and probe DNA immobilized on the electrode surface. DNA hybridization on the electrode surface could be accelerated by the electrokinetic forces. The level of hybridization was represented by the fluorescent signal intensity ratio. Results revealed that such 5-min dynamic hybridization increased 4.5 fold of signal intensity ratio as compared to a 1-h static hybridization. Moreover, dynamic hybridization was found to have better differentiation ability between specific and non-specific target DNA. This study provides a strategy to accelerate DNA hybridization in microsystems.
authors: Graduate Institute of Medical Mechatronics, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan; Department of Mechanical Engineering, Chang Gung University, Taiwan. Electronic address: kflei@mail.cgu.edu.tw.
authors: Kin Fong
authors: KF
authors: Lei
authors: Graduate Institute of Medical Mechatronics, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan.
authors: Yun-Hsiang
authors: YH
authors: Wang
authors: Department of Engineering and System Science, National Tsing Hua University, Taiwan; Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Tsing Hua University, Taiwan; Research Center for Applied Sciences, Academia Sinica, Taiwan.
authors: Huai-Yi
authors: HY
authors: Chen
authors: Department of Mechanical Engineering, Chang Gung University, Taiwan.
authors: Jia-Hong
authors: JH
authors: Sun
authors: Research Center for Applied Sciences, Academia Sinica, Taiwan.
authors: Ji-Yen
authors: JY
authors: Cheng
mesh_terms: D015342:DNA Probes / Q000737:chemistry*; D004273:DNA, Neoplasm / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D006801:Humans; D007700:Kinetics; D008297:Male; D035683:MicroRNAs / Q000737:chemistry; D008839:Microelectrodes; D044085:Microfluidics / Q000379:methods*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D011471:Prostatic Neoplasms / Q000737:chemistry
chemical_list: D015342:DNA Probes; D004273:DNA, Neoplasm; C505362:MIRN16 microRNA, human; D035683:MicroRNAs
keywords: DNA hybridization; Electrokinetics; Genetic diagnostics; Microfluidics