Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Rapid Concentration of Nanoparticles with DC Dielectrophoresis in Focused Electric Fields | Nanoscale Res Lett 2010 5 55-60 DOI s11671-009-9442-3 NANO EXPRESS Rapid Concentration of Nanoparticles with DC Dielectrophoresis in Focused Electric Fields Dafeng Chen Hejun Du Chee Yong Tay Received 24 August 2009 Accepted 18 September 2009 Published online 1 October 2009 to the authors 2009 Abstract We report a microfluidic device for rapid and efficient concentration of micro nanoparticles with direct current dielectrophoresis DC DEP . The concentrator is composed of a series of microchannels constructed with PDMS-insulating microstructures for efficiently focusing the electric field in the flow direction to provide high field strength and gradient. The location of the trapped and concentrated particles depends on the strength of the electric field applied. Both streaming DEP and trapping DEP simultaneously take place within the concentrator at different regions. The former occurs upstream and is responsible for continuous transport of the particles whereas the latter occurs downstream and rapidly traps the particles delivered from upstream. The performance of the device is demonstrated by successfully concentrating fluorescent nanoparticles. The described microfluidic concentrator can be implemented in applications where rapid concentration of targets is needed such as concentrating cells for sample preparation and concentrating molecular biomarkers for detection. Keywords Microfluidics DC dielectrophoresis Nanoparticles Electrokinetics Introduction The ability to concentrate or extract micro nanoparticles such as cells viruses bacteria and DNA from the D. Chen H H. Du C. Y. Tay School of Mechanical Aerospace Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore e-mail dfchen@ background matrix is essential to many biomedical applications. The form of these particles in high concentration facilitates the subsequent analytical and processing steps. For example current methods in microbial analysis of .
