Polyshrink™ based microfluidic chips and protein microarrays

A new approach for the rapid production of microfluidic chips integrating protein spots is described. The technology, called “Print-n-Shrink”, is based on the screen-printing of a microfluidic design (using a dielectric ink) onto Polyshrink™ polystyrene sheets. The initial printing which have a minimum size of 15 μm (height) × 230 μm (width) was thermally treated (30 s, 163 °C) to shrink and generate features of 85 μm (height) × 100 μm (width). Protein spots were also demonstrated to be shrinkable and arrays of 50 μm-size spots with density up to 6400 spots/cm2 were achieved. Proteins such as monoclonal antibodies or cellular adhesion proteins were thus spotted onto the Polyshrink™ sheets and shrunk together with the microfluidic design, creating complete biochips integrating both complex microfluidic designs and protein spots for bioanalytical applications. These shrunk spots were shown to host enough active proteins to enable the achievement of both sensitive sandwich immunoassays (Brain Natriuretic Peptide, C-Reactive Protein and c-Troponin I) and localized cell culture.