Highly sensitive polymer-based cantilever-sensors for DNA detection

8 páginas, 5 figuras, 1 tabla.-- PACS: 87.80.−y; 87.17.Gg; 07.10.Cm; 87.83.+aWe present a technology for the fabrication of cantilever arrays aimed to develop an integrated biosensor micro-system. The fabrication process is based on spin coating of the photosensitive polymer and near-ultraviolet exposure. Arrays of up to 33 microcantilevers are fabricated in the novel polymer material SU-8. The low Young’s modulus of the polymer, 40 times lower than that of silicon, enables to improve the sensitivity of the sensor device for target detection. The mechanical properties of SU-8 cantilevers, such as spring constant, resonant frequency and quality factor are characterized as a function of the dimensions and the medium. The devices have been tested for measurement of the adsorption of single stranded DNA and subsequent interstitial adsorption of lateral spacer molecules. We demonstrate that sensitivity is enhanced by a factor of six compared to that of commercial silicon nitride cantilevers.The authors acknowledge P. Rasmussen and L. G. Carrascosa for fruitful discussion. M. C. acknowledges financial support from I3P-CSIC and MERG-CT-2004-510638. J. T. and M. A. acknowledge financial support from MCyT (BIO2001-1235- C03-01 and GEN2001-4856-C13-11).M. C. acknowledges financial support from I3P-CSIC and MERG-CT-2004-510638. J. T. and M. A. acknowledge financial support from MCyT (BIO2001-1235- C03-01 and GEN2001-4856-C13-11).Peer reviewe