Screen printing as cost-efficient fabrication method for DNA-chips with electrical readout for detection of viral DNA.

The fast development in the field of DNA analytics is driven by the need for cost-effective and high-throughput methods for the detection of biomolecules. The detection of DNA using metal nanoparticles as labels is an interesting alternative to the standard fluorescence technique. Fluorescence is highly sensitive and broadly established, but shows limitations, for example instability of the signal and the requirement for sophisticated and high-cost equipment. A recently developed approach realizes a method for the electrical detection of DNA, based on the induction of silver nanoparticles growth in microelectrode gaps on the surface of a DNA-chip. This breakthrough towards robust and cost-effective detection was still hampered by the need for microstructured (and therefore expensive) substrates. We demonstrate that it is possible to utilize screen printed electrode structures for a chip-based electrical DNA detection. The electrode structures were produced on a glass substrate which made an additional optical readout possible. The screen printed structures show the required precision and are compatible with the applied biochemical protocols. A comparison with chip substrates produced by standard photolithography showed the same sensitivity and specificity for the screen printed chips. Screen printing of electrode structures for DNA-chip with electrical detection offers an interesting and cost-efficient possibility to produce DNA-chips with microstructured electrodes.