文献类型：期刊文献

英文题名：On-chip manipulation of continuous picoliter-volume superparamagnetic droplets using a magnetic force

作者：Zhang, Kai[1,2];Liang, Qionglin[1];Ma, Sai[1];Mu, Xuan[2];Hu, Ping[3];Wang, Yiming[1];Luo, Guoan[1,2]

机构：[1]Tsinghua Univ, Dept Chem, Key Lab Bioorgan Phosphorus Chem & Chem Biol, Minist Educ, Beijing 100084, Peoples R China;[2]E China Univ Sci & Technol, Sch Pharm, Shanghai 200237, Peoples R China;[3]E China Univ Sci & Technol, Sch Chem & Mol Engineer, Shanghai 200237, Peoples R China

年份：2009

卷号：9

期号：20

起止页码：2992

外文期刊名：LAB ON A CHIP

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000270285600019)】；

基金：This research was supported by funding from the National Basic Research Program (973 Program) of China (2007CB714505) and the Ministry of Education of China (No. 20080031012).

语种：英文

摘要：A microfluidic device for generating monodisperse superparamagnetic droplets and rapidly manipulating desired droplets into designated sub-microchannels by an external magnetic force is described. Superparamagnetic magnetite (Fe3O4) nanoparticles are synthesized by a chemical co-precipitation method. They are well dispersed in the water-phase to form a superparamagnetic fluid that is sheared into picoliter-volume monodisperse superparamagnetic droplets by the oil-phase in a T-junction PDMS microchannel. Superparamagnetic droplets always flow into sub-microchannel 1 due only to laminar flow without a magnetic field. But they are deflected from the direction of laminar flow by a perpendicular magnetic field. The results show that the deflection is proportional to the magnetic field gradient and magnetic nanoparticle concentration, and it is closely related to the magnet position. The observed experimental results make a good match with theoretical analysis. Single or bulk superparamagnetic droplets are successfully manipulated into the designated sub-microchannels 2 and 3 respectively, only by changing the positions of the magnet. Relatively high efficiency is obtained with more than 10 superparamagnetic droplets precisely manipulated per second. This simple and robust apparatus has wide applications in high throughput drug delivery/screening, immunoassay, cell research and synthesis of magnetic microparticles due to good biological compatibility and monodispersity of superparamagnetic droplets.