Micromechanical aptasensor-based protein detection using a compact-disc format microfluidics system

A plug-and-play CD-like platform is used to perform a statistical detection of Platelet Derived Growth Factor (PDGF) proteins through aptamer-based surface functionalization of microcantilevers. When PDGF proteins bind to the aptamers, the cantilevers deflect. This deflection is monitored by optical readout heads from a DVD-ROM. The improved sensing platform facilitates measurements in continuous liquid flow with temperature control. Also, the wobbling of the CD platform has been reduced to a minimum and the scanning system has been optimized in order to detect cantilever deflections in liquid in the nanometer range. The capability of the sensing platform is demonstrated by detection of clinically relevant concentrations of PDGF proteins. We have performed statistical measurements on 100 microcantilevers at different concentrations of PDGF, ranging from 10 nM to 400 nM. Hereby it is possible to reliably characterize the averaged mechanical response of cantilevers as a function of protein concentration.