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Fluorescence image (10X) of APTES-modified Si substrates attached in patterns and immobilized
with 29 nm latex-CHO nanoparticles. Areas of black were regions covered by photoresist during modification procedures via
photolithography
Position
PhD Student
Field of Study
Chemistry, Surface Modification,
Molecular Nanotechnology
Qualifications
B.Sc (Hons) 1st Class
Top Achievers Doctoral TEC
Scholarship
Student Room 652
Telephone: +64 3 364 2987 Extn 7437 Fax: +64 3 364 2110
Personal Mobile: +64-(0)-211355874
Email/MSN: samuelscyu@hotmail.com
Link: http://macdiarmid.ac.nz/opportunities/students/yu.php
Current research and professional activities
"The Fabrication of Micro and Nanoscale Molecular Systems
on Surfaces"
This research will address a major challenge in molecular nanotechnology:
the fabrication of molecular systems on surfaces with nanoscale precision. Patterning surfaces with chemical functionalities
is an important objective for preparing functional materials with potential applications in areas of nanotechnology such as
molecular electronics, biotechnology (DNA biochips), microelectromechanical systems technology (MEMS) and sensor devices.
Developing the capability to controllably graft simple molecules
onto surfaces in patterns and to assemble functional species (e.g: nanoparticles and/or recognition molecules) on these patterned
arrays to form larger structural aggregates is of fundamental importance in the bottom-up fabrication of molecular architectures
and novel/smart materials. We sought to develop the substrate
materials and methods to form novel composite materials that incorporate both silicon and carbon in the same substrate, which
can then be modified to give areas that exhibit different chemical properties. Composite hybrid structures were fabricated
by the pyrolysis of photoresist materials in combination with utilising photolithography technology. The photoresist material
carbonises during pyrolysis and deposit as a thin film that behaves similarly to commercially available glassy carbon that
has a near atomically smooth surface with RMS roughness between 0.2 – 0.6 nm.
Pyrolytic carbon and glassy carbon substrate materials are
modified via UV-induced and electrochemically induced coupling methods (i.e: reduction of diazoniums, oxidation
of aryl carboxylates and amines) for chemical functionalisation & patterning. The resultant nano molecular thin films are
studied with AFM, SEM, XPS, Contact Angle, Electrochemistry (Cyclic Voltammetry).
The long term goal is to develop the capabilities to immobilize novel medicinal/biomolecules
at surface to study their chemical properties and interactions.
Professional Publications:
Dynamic Behavior of Organic Thin Films Attached to Carbon Surfaces,
Samuel S. C. Yu and Alison J. Downard
e-J.
Surf. Sci. Nanotech. Vol. 3, pp. 294-298
Link: http://www.jstage.jst.go.jp/article/ejssnt/3/0/3_294/_article
Effect of Applied Potential on Arylmethyl Films Oxidatively
Grafted to Carbon Surfaces
Samuel S. C. Yu, Paula A. Brooksby, Alison J. Downard, Langmuir; 2005; 21(24) pp 11304 - 11311
Link: http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/la051964c
* Front Cover for New Journal of Chemistry, Issue 9
2006 *
Controlled assembly of
gold nanoparticles on carbon surfaces
Alison J. Downard, Emelyn S. Q. Tan and Samuel S. C. Yu,
New J. Chem., 2006
link:
http://www.rsc.org/Publishing/Journals/NJ/article.asp?doi=b605219c
Photochemical & Activation of Organic Layers on Glassy Carbon and Pyrolyzed Photoresist Films,
Samuel Yu and Alison Downard, Langmuir, 23, 4662-4668 (2007)
Link: http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/la063532n
International Presentations and Conferences :
Samuel Yu, Alison J Downard, Photochemical & Electrochemical Preparation
of Molecular Films on Carbon Surfaces, 3rd International Conference on Advanced Materials and Nanotechnology
(AMN-3) Wellington, New Zealand, 2007
Surface Functionalization of Materials, The 2006 MacDiarmid Institute Student and Postdoc Symposium, Christchurch, New Zealand,
2006
Samuel Yu, Alison J Downard, Electrochemical and Photochemical Surface Modification
of Carbon Surfaces with Nano-Dimensioned
Molecular Films, The 3rd International Conference on Advances of
Thin Films and Coatings (Thin Films 2006), 11-15 December 2006, Singapore
The effects of applied potential on organic films electrochemically
grafted to carbon electrodes, International Symposium on Functional Materials (Invited
Talk), Kuala Lumpur Malaysia, 2005
Samuel Yu & Alison Downard, An
AFM and Electrochemical study of organic thin-films covalently attached to carbon electrodes, Presentation
to International Symposium on Surface Science, Omiya Sonic City, Japan, 2005 *Excellent
Young Researchers Prize
Samuel Yu, Alison J Downard, Paula Brooksby, Emelyn Tan,
Fabrication and surface modification of composite carbon and silicon hybrid materials, 2nd International
Conference on Advanced Materials and Nanotechnology (AMN-2) Queenstown, New Zealand, 2004
Yu, S.S.C., Downard, A.J., Brooksby, P.A., Blaikie, R.J., Conference
presentation at New Zealand Institute of Chemistry NZIC 2003 Conference, Nelson, December 1-4, 2003, Fabrication
and modification of patterned carbon and silicon microstructures
The Fabrication, Characterization and Chemical Patterning of Molecular NanoThin-Films Covalently
Grafted to Carbon Electrodes, Samuel S.C Yu, The Chinese University of Hong Kong, Department of Chemistry (Kindly
Invited by Prof Henry Wong), Hong Kong
*See "Presentation" for some presented posters
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