Abstract: The present invention provides a substrate for a microfluidic device comprising a polymeric base plate, at least one sensor formed over the polymeric base plate for detecting at least one target analyte from a sample, the sensor comprising at least one reference electrode and at least one working electrode, wherein a plurality of nanostructures deposited over the working electrode for increasing the surface area of the working electrode, and at least one recognition element bound to or deposited over the nanostructures. The microfluidic device of the present invention is a point-of-care, self calibrated, self contained hand-held device for rapid screening and diagnosis of various disease markers.