Keywords

Nanoparticles characterization; nanoparticles size measurement; vesicles characterization; resistive pulse method; glass capillary; nanopore; nanopipette; capillary ionic transistor

Abstract

The ability to precisely count inorganic and organic nanoparticles and to measure their size distribution plays a major role in various applications such as drug delivery, nanoparticles counting, and many others. In this work I present a simple resistive pulse method that allows translocations, counting, and measuring the size and velocity distribution of silica nanoparticles and liposomes with diameters from 50 nm to 250 nm. This technique is based on the Coulter counter technique, but has nanometer size pores. It was found that ionic current drops when nanoparticles enter the nanopore of a pulled micropipette, producing a clear translocation signal. Pulled borosilicate micropipettes with opening 50 ~ 350 nm were used as the detecting instrument. This method provides a direct, fast and cost-effective way to characterize inorganic and organic nanoparticles in a solution. In this work I also introduce a newly developed Capillary Ionic Transistor (CIT). It is presented as a nanodevice which provides control of ionic transport through nanochannel by gate voltage. CIT is Ionic transistor, which employs pulled capillary as nanochannel with a tip diameter smaller than 100 mm. We observed that the gate voltage applied to gate electrode, deposited on the outer wall of a capillary, affect a conductance of nanochannel, due to change of surface charge at the solution/capillary interface. Negative gate voltage corresponds to lower conductivity and positive gate increases conductance of the channel. This effect strongly depends on the size of the channel. In general, at least one dimension of the channel has to be small enough for electrical double layer to overlap.

Notes

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Graduation Date

2014

Semester

Fall

Advisor

Chow, Lee

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Physics

Degree Program

Physics

Format

application/pdf

Identifier

CFE0005880

URL

http://purl.fcla.edu/fcla/etd/CFE0005880

Language

English

Release Date

June 2018

Length of Campus-only Access

3 years

Access Status

Doctoral Dissertation (Campus-only Access)

Subjects

Dissertations, Academic -- Sciences; Sciences -- Dissertations, Academic

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