Manipulating and heating discrete droplets using magnetic porous silicon microparticles

INOR 315

Ester Segal, essegal@ucsd.edu1, Ji-Ho Park, jpark@ucsd.edu2, Austin M. Derfus, aderfus@ucsd.edu3, Sangeeta N. Bhatia4, and Michael J. Sailor, msailor@ucsd.edu1. (1) Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, (2) Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, (3) Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, (4) Division of Health Sciences and Technology (Harvard-MIT), Massachusetts Institute of Technology, 77 Massachusetts Avenue, Bldg. E19-502d, Cambridge, MA 02139
A method for manipulating and heating discrete micro-liter scale liquid droplets using magnetic amphiphilic porous silicon (Si) microparticles will be described. The magnetic porous Si microparticles consist of two layers: the top layer contains a photonic code and it is hydrophobic. The bottom layer consists of a hydrophilic Si oxide host layer that is infused with magnetite nanoparticles. The resulting magnetic amphiphilic microparticles spontaneously align at the interface of an aqueous droplet immersed in oil, allowing manipulation of the droplets by a magnet. Heating of the enclosed droplet is achieved by application of an external alternating radio frequency electromagnetic field. A simple microreaction is demonstrated by melting complementary oligonucleotides contained in separate droplets and then thermally inducing dehybridization of the conjugate. The technique demonstrates the feasibility of tagging, manipulating, and heating small volumes of liquids without the use of conventional microfluidic channels and heating systems.
 

Nanoscience: Applications
7:00 PM-10:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Inorganic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006