Weighing nanoparticles in solution at the attogram scale.
Physical characterization of nanoparticles is required for a wide range of applications. Nanomechanical resonators can quantify the mass of individual particles with detection limits down to a single atom in vacuum. However, applications are limited because performance is severely degraded in solution. Suspended micro- and nanochannel resonators have opened up the possibility of achieving vacuum-level precision for samples in the aqueous environment and a noise equivalent mass resolution of 27 attograms in 1-kHz bandwidth was previously achieved by Lee et al. [(2010) Nano Lett 10(7):2537-2542]. Here, we report on a series of advancements that have improved the resolution by more than 30-fold, to 0.85 attograms in the same bandwidth, approaching the thermomechanical noise limit and enabling precise quantification of particles down to 10 nm with a throughput of more than 18,000 particles per hour. We demonstrate the potential of this capability by comparing the mass distributions of exosomes produced by different cell types and by characterizing the yield of self-assembled DNA nanoparticle structures.
Departments of Biological Engineering, Materials Science and Engineering, Electrical Engineering and Computer Science, and Mechanical Engineering, Koch Institute for Integrative Cancer Research, Computational and Systems Biology Initiative, Harvard-MIT Health Sciences and Technology, Institute for Medical Engineering and Science, and Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, MA 02139.
Selim
S
Olcum
Nathan
N
Cermak
Steven C
SC
Wasserman
Kathleen S
KS
Christine
Hiroshi
H
Atsumi
Kris R
KR
Payer
Wenjiang
W
Shen
Jungchul
J
Lee
Angela M
AM
Belcher
Sangeeta N
SN
Bhatia
Scott R
SR
Manalis
D055354:Exosomes; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles; D008970:Molecular Weight; D015203:Reproducibility of Results; D012996:Solutions
D012996:Solutions; D006046:Gold
NEMS; mechanical oscillators; microfluidics; nanoparticle characterization