Research On Microarray Chip For Bioparticle Capture

Microarray technology provides a method for rapid detection of proteins, nucleicacids, cells and other bioparticles. Bioparticle capture is a fundamental work in biology,pharmacy, diagnosis and other fields. Sample can be purified by capturing the otherimpurities biology particles in it, disease diagnosis can be done by capturing some specificproteins or cells. Moreover, capture technology can locate particles in designed places tomanufacture biosensors.In this paper a microarray chip for biology particles capture in solution is design andmanufactured. The chip is made of n-type silicon wafer, with a size of22mm×22mm. Thecapture area is60×60microposts array. The diameter of a single micropost is100μm, andthe height is100μm, too. The microposts’ center distance is150μm. The microposts arrayis manufactured by lithography, magnetron sputtering, lift-off and ICP etching. During theetching, increasing the substrate temperature and etching/passivation ratio is applied tocontrol the micrograss, a gas mixture of SF6and C4F8is applied to smooth the sidewallroughness. Optimized parameters such as substrate temperature, etching/passivation time,gas mixture ratio are obtained by experiment.Chip modification consists of Au nanoparticles preparation and MUA monolayersassembly. Au nanoparticles are prepared by immersing chips into HAuCl4solutioncontaining HF, and MUA monolayers assembled on the gold is obtained by immersingchips into ethanol resolution containing MUA.Specific protein is modified on MUA monolayers to capture bioparticles. Antibodycapture and cell capture are carried out on microarray chips. The chip has a captureefficiency of72％~86％to antibody, and80％to cell.