Paper NS1+BI-WeA4
Carbon Nanotube - Chitosan Sites for Direct Electrical Sensing of Biomolecular Events in BioMEMS

Wednesday, October 17, 2007, 2:40 pm, Room 615

Direct electrical sensing of biomolecular events is highly desirable in bioMEMS applications such as metabolic engineering platforms or biosensor systems. We are pursuing the development and integration of carbon nanotube (CNT) thin film biosensing devices in the microfluidic systems we employ for recreating metabolic pathways for drug discovery. Since these systems exploit chitosan electrodeposition as a spatiotemporally programmable reaction site for biomolecular binding and enzymatic activity, CNT biofunctionalization using chitosan would enable fabrication of the microfluidics environment with embedded CNT devices so that the devices could serve as active sites for biomolecular events and simultaneously read out those events electrically. We have developed integrated CNT devices, for use as conductance elements and/or FET’s, and an easily fabricated, reusable microfluidic system using SU8 channels and a PDMS gasket for non-permanent sealing. In addition, we have electrodeposited chitosan, an amine-rich polysaccharide, onto CNT mats exposed as active sites for biomolecular binding down to 1 μm resolution. Since we have already demonstrated that proteins,¹ nucleic acids, and viruses² can be conjugated to localized chitosan sites in bioMEMS and retain their biomolecular functionality, we believe the integrated CNT devices are promising for sensing and controlling biomolecular assembly in multi-site bioMEMS networks that recreate metabolic pathways. This work is supported in part by the Robert W. Deutsch Foundation.

¹Park, J.J., et al., Chitosan-mediated in situ biomolecule assembly in completely packaged microfluidic devices. Lab on a Chip, 2006. 6(10): p. 1315-1321.
²Yi, H.M., et al., Patterned assembly of genetically modified viral nanotemplates via nucleic acid hybridization. Nano Letters, 2005. 5(10): p. 1931-1936.