Controlled deposition of gold nanoparticles on polystyrene
Ladda ner
Typ
Examensarbete för masterexamen
Program
Nanotechnology (MPNAT), MSc
Publicerad
2021
Författare
Nedin, Filip
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Gold nanoparticle (AuNP) number density gradients functionalised with
(bio)molecules have applications in the study of e.g. stem cell differentiation.
Currently, AuNP number density gradients are available on glass substrates, but
many cell cultivation studies are performed on plastic substrates, e.g. polystyrene.
Therefore, it is of interest to investigate if AuNP number density gradients can be
achieved also on polystyrene.
This thesis investigates several methods of depositing AuNPs on polystyrene
substrates. The experimental work is limited to uniform AuNP deposition, thus
covering a first step towards AuNP gradients on polystyrene substrates. Two
different functionalisation paths were tested: silanisation with aminosilane
(APDMES, 3-aminopropyldimethylethoxysilane) and coating with poly-l-lysine
(PLL). For the silanisation, O2 plasma, UV/O3 treatment and (base) piranha wash
were tested as oxidising pre-treatments. For coating with PLL, O2 plasma was
tested as pre-treatment for increased surface wettability. AuNP deposition for the
different functionalisation methods is determined by scanning electron
microscopy (SEM) and the functionalisation methods are evaluated in terms of
AuNP number density and range of interparticle dispersion, as determined by
spatial descriptive statistics (Ripley’s K function). Furthermore, a rudimental
extended random sequential adsorption (RSA) computational model is developed
for the system.
Of the tested functionalisation methods, silanisation with pre-treatment by UV/O3
exhibited the most promising results with AuNP number density of same order of
magnitude as on glass reference samples (5.73 ∙ 1014 m-2, compared to 2.48 ∙ 1015
m-2 for the glass reference) and similar range of dispersion (75 nm, compared to
40-60 nm for the glass reference). It should, however, be noted that the
conclusions are based on few experiments and need to be verified by additional
experiments. The computational model seems to capture the basic phenomena of
AuNP adsorption but underestimates the AuNP number density and the
interparticle potential, or at least the range of the interparticle potential.
Beskrivning
Ämne/nyckelord
AuNP, , gradient , polystyrene , APDMES , PLL