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Resistive pulse sensing of analyte-induced multicomponent rod aggregation using tunable pores
journal contribution
posted on 2013-01-11, 13:47 authored by Mark PlattMark Platt, Geoff R. Willmott, Gil U. LeeResistive pulse sensing is used to monitor individual and aggregated rod-shaped nanoparticles as they move through tunable pores in elastomeric membranes. By comparing particles of similar dimensions, it is demonstrated that the resistive pulse signal of a rod is fundamentally different from that of a sphere. Rods can be distinguished using two measurements: the blockade event magnitude (Δip), which reveals the particle's size, and the full width at half maximum (FWHM) duration, which relates to the particle's speed and length. While the observed Δip values agree well with simulations, the measured FWHM times are much larger than expected. This increase in dwell time, caused by rods moving through the pore in various orientations, is not observed for spherical particles. These differences are exploited in a new agglutination assay using rod-shaped particles. By controlling the surface chemistry and location of the capture ligand, rods are made to form either long “end-on-end” or wide “side-on” aggregates upon the addition of an analyte. This observation will facilitate multiplexed detection in agglutination assays, as particles with a particular aspect ratio can be distinguished by two measurements. This is first demonstrated with a biotinylated target and avidin capture probe, followed by the detection of platelet-derived growth factor (PDGF-BB) using an aptamer capture probe, with limits of detection down to femtomolar levels.
History
School
- Science
Department
- Chemistry
Citation
PLATT, M., WILLMOTT, G.R. and LEE, G.U., 2012. Resistive pulse sensing of analyte-induced multicomponent rod aggregation using tunable pores. Small, 8 (15), pp. 2436 - 2444.Publisher
© WILEY-VCH Verlag GMBHVersion
- AM (Accepted Manuscript)
Publication date
2012Notes
Closed Access. This article was published in the journal, Small [© WILEY-VCH Verlag GMBH] and the definitive version is available at: http://dx.doi.org/10.1002/smll.201200058ISSN
1613-6810Publisher version
Language
- en