Fabrication of Polystyrene Core-Silica Shell Nanoparticles for Scintillation Proximity Assay (SPA) Biosensors

Persistent Link:
http://hdl.handle.net/10150/556865
Title:
Fabrication of Polystyrene Core-Silica Shell Nanoparticles for Scintillation Proximity Assay (SPA) Biosensors
Author:
Noviana, Eka
Issue Date:
2015
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Embargo:
Release after 21-May-2016
Abstract:
The development of analytical tools for investigating biological pathways on the molecular level has provided insight into diseases and disorders. However, many biological analytes such as glucose and inositol phosphate(s) lack the optical or electrochemical properties needed for detection, making molecular sensing challenging. Scintillation proximity assay (SPA) does not require analytes to possess such properties. SPA uses radioisotopes to monitor the binding of analytes to SPA beads. The beads contain scintillants that emit light when the radiolabeled analytes are in close proximity. This technique is rapid, sensitive and separation-free. Conventional SPA beads, however, are large relative to the cells and made of hydrophobic organic polymers that tend to aggregate or inorganic crystals that sediment rapidly in aqueous solution, thus limiting SPA applications. To overcome these problems, polystyrene core-silica shell nanoparticles (NPs) doped with pTP and dimethyl POPOP were fabricated to produce scintillation NPs that emit photons in the blue region of visible light. The developed scintillation particles are approximately 250 nm in diameter (i.e. 200 nm of core diameter and 10-30 nm of shell thickness), responsive to β-decay from tritium (³H) and have sufficient stability in the aqueous media. DNA hybridization-based SPA was performed to determine whether the scintillation NPs could be utilized for SPA applications. A 30-mer oligonucleotide was immobilized on the polystyrene core-silica shell NPs to give approximately 7.6 x 10³ oligonucleotide molecules per NP and ³H-labeled complementary strand was annealed to the immobilized strand. At the saturation point, increases in scintillation signal due to oligonucleotide binding to the NPs were about 9 fold compared to the control experiments in which no specific binding occurred, demonstrating that the scintillation NPs can be utilized for SPA. Along with the improved physical properties including smaller size and better stability in the aqueous system, the developed scintillation NPs could be potentially useful as biosensors in cellular studies.
Type:
text; Electronic Thesis
Keywords:
nanoparticles; polystyrene-silica; scintillation proximity assay; Chemistry; biosensor
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Aspinwall, Craig A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleFabrication of Polystyrene Core-Silica Shell Nanoparticles for Scintillation Proximity Assay (SPA) Biosensorsen_US
dc.creatorNoviana, Ekaen
dc.contributor.authorNoviana, Ekaen
dc.date.issued2015en
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.releaseRelease after 21-May-2016en
dc.description.abstractThe development of analytical tools for investigating biological pathways on the molecular level has provided insight into diseases and disorders. However, many biological analytes such as glucose and inositol phosphate(s) lack the optical or electrochemical properties needed for detection, making molecular sensing challenging. Scintillation proximity assay (SPA) does not require analytes to possess such properties. SPA uses radioisotopes to monitor the binding of analytes to SPA beads. The beads contain scintillants that emit light when the radiolabeled analytes are in close proximity. This technique is rapid, sensitive and separation-free. Conventional SPA beads, however, are large relative to the cells and made of hydrophobic organic polymers that tend to aggregate or inorganic crystals that sediment rapidly in aqueous solution, thus limiting SPA applications. To overcome these problems, polystyrene core-silica shell nanoparticles (NPs) doped with pTP and dimethyl POPOP were fabricated to produce scintillation NPs that emit photons in the blue region of visible light. The developed scintillation particles are approximately 250 nm in diameter (i.e. 200 nm of core diameter and 10-30 nm of shell thickness), responsive to β-decay from tritium (³H) and have sufficient stability in the aqueous media. DNA hybridization-based SPA was performed to determine whether the scintillation NPs could be utilized for SPA applications. A 30-mer oligonucleotide was immobilized on the polystyrene core-silica shell NPs to give approximately 7.6 x 10³ oligonucleotide molecules per NP and ³H-labeled complementary strand was annealed to the immobilized strand. At the saturation point, increases in scintillation signal due to oligonucleotide binding to the NPs were about 9 fold compared to the control experiments in which no specific binding occurred, demonstrating that the scintillation NPs can be utilized for SPA. Along with the improved physical properties including smaller size and better stability in the aqueous system, the developed scintillation NPs could be potentially useful as biosensors in cellular studies.en
dc.typetexten
dc.typeElectronic Thesisen
dc.subjectnanoparticlesen
dc.subjectpolystyrene-silicaen
dc.subjectscintillation proximity assayen
dc.subjectChemistryen
dc.subjectbiosensoren
thesis.degree.nameM.S.en
thesis.degree.levelmastersen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplineChemistryen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorAspinwall, Craig A.en
dc.contributor.committeememberHeien, Michael L.en
dc.contributor.committeememberPyun, Jeffreyen
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