Synthesis of silica-based nanomaterials and their applications in fluorescent, biological and chemical sensing
Author
Beyazkılıç, Pınar
Advisor
Elbüken, Çağlar
Date
2018-06Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
120
views
views
0
downloads
downloads
Abstract
This thesis describes development of nanoparticle-based liquid sensors and coatings
for droplet-based bioassays. Liquid sensors were produced from mesostructured
(2-50 nm) hybrid silica nanoparticles. Detection of trace trinitrotoluene
(TNT) and dopamine in aqueous phase was shown based on
uorescence of
nanoparticles. Silica nanoparticles were synthesized using a facile one-pot solgel
method. Pyrene molecules were hybridized with hydrophobic parts of
cetyltrimethylammonium micelles followed by silica growth around micelles.
Nanoparticles showed good dispersibility and colloidal stability in water. Pyrene
exhibited bright and highly stable emission. Pyrene emission exhibited a rapid,
sensitive and visual
uorescence quenching against TNT and dopamine.
For droplet-based assays, robust superhydrophilic patterned superhydrophobic
coatings were developed. Biomolecular adsorption and droplet mixing were
shown on coatings which were prepared using sol-gel method followed by ultraviolet/
ozone (UV/O) treatment.
Droplet-based biomolecular detection platforms were developed using superhydrophilic
patterned superhydrophobic surfaces. Bene tting from con nement and
evaporation-induced shrinkage of droplets on wetted patterns, sensitive glucose
and DNA detection was demonstrated. Glucose was detected based on enhancement
of polydopamine (PDA) emission by hydrogen peroxide (H2O2) produced
in glucose oxidation reaction. Detection in evaporating droplets resulted with
bright
uorescence and high sensitivity for analyte molecules. This was due to
droplet evaporation which concentrated molecules and increased reaction rates.
Surfaces and nanoparticles developed in this thesis hold great potential for biological
and chemical analysis with low sample volumes owing to their simple
production, sensitive detection responses and versatility.