Integrated measurement of the mass and surface charge of discrete microparticles using a suspended microchannel resonator
Name
Manalis-2009-Integrated Measurement of the Mass and Surface Charge of Discrete '.pdf
Size
672.85 KB
Format
Adobe PDF
Checksum (MD5)
a28e775b3743c71dd4a12ccfb77cf6f2
Author(s)
Dextras, Philip
Burg, Thomas P.
Manalis, Scott R.
Date Issued
May 2009
Journal
Analytical Chemistry
Publisher
American Chemical Society
Citation
Dextras, Philip, Thomas P. Burg, and Scott R. Manalis. “Integrated Measurement of the Mass and Surface Charge of Discrete Microparticles Using a Suspended Microchannel Resonator.” Analytical Chemistry 81 (2009): 4517-4523. Web. 16 Nov. 2011. © 2009 American Chemical Society
Version
Author's final manuscript
Abstract
Measurements of the mass and surface charge of microparticles are employed in the characterization of many types of colloidal dispersions. The suspended microchannel resonator (SMR) is capable of measuring individual particle masses with femtogram resolution. Here, we employ the high sensitivity of the SMR resonance frequency to changes in particle position, relative to the cantilever tip, to determine the electrophoretic mobility of discrete particles in an applied electric field. When a sinusoidal electric field is applied to the suspended microchannel, the transient resonance frequency shift corresponding to a particle transit can be analyzed by digital signal processing to extract both the buoyant mass and electrophoretic mobility of each particle. These parameters, together with the mean particle density, can be used to compute the size, absolute mass, and surface charge of discrete microspheres, leading to a true representation of the mean and polydispersity of these quantities for a population. We have applied this technique to an aqueous suspension of two types of polystyrene microspheres, to differentiate them based on their absolute mass and their surface charge. The integrated measurement of electrophoretic mobility using the SMR is determined to be quantitative, based on comparison with commercial instruments, and exhibits favorable scaling properties that will ultimately enable measurements from mammalian cells.
Description
Supporting Information Available: Detailed examinations of the algorithms that have been described in the manuscript for use in signal processing. (PDF) This information is available free of charge via the Internet at http://pubs.acs.org.
MIT Department
Massachusetts Institute of Technology. Department of Biological Engineering
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike 3.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1021/ac9005149
