ANFF-Vic Biointerface Engineering Interfacing biology with technology

About the facility Wide range of capabilities in surface modification Thin films, polymer grafting, biomolecule immobilisation Bioactive coatings in polymers, ceramics and metals

Overview Plasma Polymerisation Langmuir Blodgett Surface Coatings And Analysis Multi Vessel Dip Coating Dip-Pen Nanolithography (DPN) Quartz Crystal Microbalance (QCM) Mask Aligner UV/Ozone Cleaner Biochemistry and Cell Biology

Plasma Polymerisation Specifications – 6 custom made reactors for plasma polymerisation (PE-CVD) – <1-100 nm thin, pinhole-free polymer coatings – Substrate independent – Up to 20cm diameter samples – Vacuum process (1 x10 -2 mbar) – Can be set up to etch, treat and deposit surfaces

How Does It Work Gaseous monomer introduced at reduced pressure Molecules fragmented by application of RF voltage – ‘glow discharge’ Fragments react with surface and each other to form highly cross linked coatings Monomer properties can be retained…control power and flow rate Etch, treat, deposit Pump Chamber Monomer Gas Air Electrode HF voltage P~10 -2 mbar * * *

Applications Chemistries – Alkanes – Alcohols – Acids – Amines – Thiols – PEO-like – Fluorocarbons – NiPAAm – Anhydrides – Hydrophobic – Hydrophilic – Alkane bromides (ATRP Initiator) – Essential Oils (antimicrobial) Substrates – Metals – Polymers – Ceramics – Semiconductors – Fibres – Patterning – PDMS

Examples Chemically Patterned Surfaces Bioarrays, biomaterials, sensors, adhesion promotion, Surface modification of electrospun fibres for improved cell growth Key References and Examples:

Langmuir Blodgett Surface Coatings And Analysis Specifications * – KSV-NIMA LB trough (medium) – Surface Area (cm2)273 – Trough top inner dimensions (LxWxH mm)364x75x4 – Maximum compression ratio10.8 – Barrier speed (mm/min) – Balance measuring range (mN/m) – Film formation on gas/liquid and liquid/liquid interface – Film deposition on solid substrates – Microscopy trough *

How Does LB Work Trough filled with water (respective liquid) Surfactant/Lipid is applied on surface of the liquid Barriers are moved inwards to reduce surface area of Liquid Surfactant rearranges on Surface Forces can be measured with a Wilhelmy plate Substrate can be dipped in solution and pulled out for monolayer formation *

Applications – Surface Tension measurements – Dip coating of substrates for monolayer formation – Lipid bilayer formation – Surfactant characterisation – Drug-membrane studies – Cell-membrane interactions Uses: Membrane Perturbation Activity of Cationic Phenylene Ethynylene Oligomers and Polymers: Selectivity against Model Bacterial and Mammalian Membranes *

KSV-NIMA Multivessel Dipcoater Multiple dipping of single substrate in different solutions Sample: – Weight (g) – Height (mm) – Width (mm) – Thickness (mm) Dipping speed: mm/min Up to 10 samples dipped simultaneously Create layer-by-layer (LbL) coatings from polyelectrolytes Assemble colloidal arrays *

Layer-by-layer (LbL) of Polyelectrolytes Science 29 August 1997: Vol. 277 no pp DOI: /science

Dip-Pen Nanolithography (DPN) Specifications – Nanoink Nscriptor – Direct writing of molecules on surfaces – Bottom-up fabrication – < 1µm patterning from supplied design – Integrates with photolithography processing Image drawn on gold using alkane thiol ink

How Does DPN Work Uses experimental set up of Atomic Force Microscopy (AFM) Three main components of DPN 1.AFM-tip as “pen” 2.Sample surface as “paper” 3.Molecular chemicals with affinity to surface as “ink” Molecules (ink) transported from tip to surface via capillary transport trough formed water meniscus

Applications Higher resolution/finer structures (sub- 100 nm) than traditional printing methods Selective patterning of different molecules at different sites on surface DPN allows multiple patterning at multiple scales/shapes/sizes Applications: – Biosensors – Cell engineering

Quartz Crystal Microbalance (QCM) Specifications – Q-Sense E4 – Number of sensors 4 – Volume above each sensor ~ 40 μl – Minimum sample volume ~ 300 μl – Working temperature 15 to 65°C, (software controlled) – Typical flow rates μl/min – Frequency and Dissipation analysis

How Does QCM Work Quartz crystal vibrates at distinct frequency Adsorbed molecules result in change of frequency Adsorbed mass correlates with frequency and can be quantified Dissipation correlates with rigidity of coating

Applications for QCM Kinetic studies of self assembly processes, thin film formation, protein and drug interactions, Viscoelastic behaviours of thin films and adsorbed/immobilised layers Adsorption kinetics of lipid vesicles are displayed as Δf(t) and ΔD(t) for vesicles extruded through 30 nm pores. Adsorption curves are presented for (a) Si 3 N 4, (b) oxidized Pt, (c) TiO 2, and (d) SiO 2

Mask Aligner Specifications – OAI Model 200 Mask Aligner and UV Exposure System – Housed in Class 1000 cleanroom – Air bearing / vacuum chuck levelling system, the substrate is leveled quickly and gently, for parallel photo mask alignment and uniform contact across the wafer during contact exposure. – The system is capable of one micron resolution and alignment precision. *

UV/Ozone Cleaner UV/Ozone cleaning of surfaces Removal of organic residues from surfaces Oxydation/Hydrophilisation of surfaces Cross linking of UV-curable resins Clean AFM tips Oxidize PDMS microfluidic devices Prepare surfaces prior to gluing

How Does The UV Cleaner Work The samples are placed underneath UV lamp UV light reacts with ambient oxygen to form Ozone Ozone is a very reactive compound that can react with a large number of organic materials to form volatile molecules like CO2 which are released into the environment UV light can also act as cross linker of alkene compounds

Biochemistry and Cell Biology PC2 laboratories for bacterial and cell culture Wide range of biochemical assays available – ELISA – Western blotting – Protein assays – Cell viability assays Confocal and Epi-fluorescence Microscopy

Biointerface Engineering Hub Contacts: – Prof Sally McArthur – Dr Thomas Ameringer