Results: We present a novel strategy that offers practical solutions to these challenges,
featuring peptide aptamers as artificial protein detectors arrayed on gold electrodes with
feature sizes one order of magnitude smaller than existing formats. We describe a method to
immobilize specific peptide aptamers on individual electrodes at the micrometer scale,
together with a robust and label-free electronic sensing system. As a proving proof of
principle experiment, we demonstrate the specific recognition of cyclin-dependent protein
kinases in whole-cell lysates using arrays of ten electrodes functionalized with individual
peptide aptamers, with no measurable cross-talk between electrodes. The sensitivity is within
the clinically relevant range and can detect proteins against the high, whole-cell lysate
background.