Dissertation/Thesis Abstract

Resistive-pulse study of translocated sub-micrometer particles through cylindrical pores
by Gutierrez, Diego, M.S., California State University, Long Beach, 2016, 56; 10169528
Abstract (Summary)

Taking inspiration from nature has promoted the production of man made pores, analogous to protein channels, providing a platform in unraveling the mechanism for nanoscale transportation. This gives insight to applications such as drug delivery, cancer detection and bio-electronics. Therefore, to gain more insight, hydrogels of different structural stiffnesses were translocated through pores with 800 nm and 500 nm diameters. The stiffness of the hydrogels were classified into 3 categories of 2%, 5% and 10% crosslink percentage, 2% being the least rigid and 10% the most. The characterization of each set of particles were classified by their resistive pulse, charge intake, average translocation time and effective particle size. It was determined that the characterization of each resistive pulse is defined by the inner structure of each pore’s imperfections. Now by focusing on each individual pore, we could see slight variations between each set of hydrogels as they translocate the unique pore. What we obtained was the translocation times for more compressible hydrogels being faster than for more rigid ones. The charge intake gave insight into the particle size, with larger charge intake into the pore referring to larger particles and smaller intake for smaller one. This made clear the notion that bigger diameter hydrogels with same crosslink percentages will translocate at a slower rate than smaller hydrogels. The other piece of data obtained was the average effective diameter for all 3 hydrogel sets at given voltages. Both 500 nm and 800 nm pores coincided in the order of effective particle size translocated, from smallest to greatest starting at 10%, 2%, and 5%, respectively. This indicates that even though the 2% crosslink is the most compressible hydrogel, it did not translocate the biggest particles. Instead the 5% crosslink hydrogels translocated the bigger sizes, meaning that the 2 extremes are not ideal for bigger particle translocation. The 10% is obviously too rigid to allow big hydrogels than the other 2 sets, but the 2% indicates that some phenomena exists that tells us a compressibility to an extreme won’t produce bigger sized translocations. The latter phenomena is still not fully understood, but because both sized pores gave the same effect and follow the same trend, it indicates the probability of this being true pretty high and with good certainty. We’ve now characterized these translocations and understand that by classifying the effects of our parameters, the properties of any given translocated object can be deciphered. This leads to the ultimate goal of using these techniques to develop applications for bio technology.

Indexing (document details)
Advisor: Kwon, Chuhee
Commitee: Pickett, Galen, Siwy, Zuzanna
School: California State University, Long Beach
Department: Physics and Astronomy
School Location: United States -- California
Source: MAI 56/02M(E), Masters Abstracts International
Subjects: Physics, Biophysics
Keywords: Compress, Dehydrate, Hydrogels, Nanopores, Resistive-pulse, Translocation
Publication Number: 10169528
ISBN: 9781369237160
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