Life Science
Gas plasma technology is commonly used to precision clean and activate, decontaminate surfaces, promote adhesion of functional bio-molecules and in conjunction with specific chemical vapors sterilize in-vivo and in-vitro medical devices.
Biosensors
Conjugation of sensor biomolecules to IVD platforms
Gas plasma provides surface conditioning of in vitro diagnostic platforms prior to the deposition of the bio sensor materials. Conditioning may simply be precision cleaning of the substrate at the molecular level, or raising the surface energy to make energy available to chemically bond to the sensor material. However, in vitro diagnostic substrates may require more selective chemistries to immobilize sensor molecules. Specific plasma processes have been developed at PVA TePla for the selective adhesion promotion and conjugation of bio active molecules. This is achieved by providing particular chemical functionality at the surface, allowing covalent coupling of biochemical species to occur. Amino, carboxylic, hydroxyl and epoxy functionalities are important examples of the chemistries that are readily obtainable using gas plasma surface treatment. PVA TePla has recently developed new methods for chemically functionalizing various polymer platforms that outperform traditional plasma techniques in terms of maximizing and controlling functionality. For example we can control the surface concentration of primary amines, achieving up to 18% surface coverage.
Microfluidics
Improve analyte flow characteristics through microfluidic channels
The function of microfluidic devices are greatly enhanced by plasma. Microchannels on clinical diagnostic devices are made wettable to bio-fluids without having an effect on the properties of the analyte itself. Microfluidic devices require hydrophilic surfaces so that the analyte flows smoothly and consistently through the microchannels to the detection and processing elements on these devices. This flow is accomplished by a variety of pumping methods; electro-osmotic, thermal, mechanical, etc. Microfluidic device platforms are usually made from polymer materials (polystyrene, polydimethylsiloxane (PDMS)) that are inherently hydrophobic. One of the major problems caused by the hydrophobic nature of these materials is bubble trapping in the microchannels that inhibit fluid flow. Even when the channels are primed with alcohol and buffer solution, air bubbles can still pose a problem. Gas plasma treatment oxidizes the surface of the microchannels, making them hydrophilic and preventing the formation of air bubbles. Flow rates are also affected by surface charge densities during electrokinetic pumping. Plasma has been shown to effectively charge surfaces supporting the electro-osmotic flow. This is another benefit of plasma treating microfluidic devices.