Selective plasma activation of surfaces for biosensing application

Summary form only given. Different gas plasma can be used for creating specific surface chemical bonds on material surfaces. These bonds can then be utilized for detection of different chemicals and biomolecules. Biosensors are currently being used for a variety of sensing ranging from medical diagnosis, drug development, food industry and environmental monitoring. The bio analyte is detected by the interaction with the biological element like protein, DNA, peptide, etc. on the surface of the sensor and the signal is transmitted as a electrical, mechanical or optical one. There is a growing demand to develop biosensing surfaces that can be easily integrated with electronics to make highly efficient analytical devices.Here we present our research on developing a biosensor platform using functionalized silicon nitride (SiNx) films. SiNx is chemically inert and easily integrated with other solid state devices and thus is an attractive material for biosensing. We utilize inductively coupled (ICP) reactive ion etcher (RIE) for plasma activation of the SiNx films. The films are functionalized using hydrogen plasma in an ICP-RIE which permits use of low power plasma to reduce the surface damage and increase the efficiency of activation. We have demonstrated high number of amine bonds on the surface in the range of 5 x 1012 /cm2. This was measured by attaching m-Cherry protein to the surface using a light activated crosslinker. Due to the high surface activation efficiency a small area sensor can be developed with high sensitivity. Different proteins can be attached for sensing different biomolecules. Results from this research will be presented.