Label-free sub-picomolar protein detection with extended-gate field-effect transistors (original) (raw)

Proteins mediate the bulk of biological activity and are powerfully assayed in the diagnosis of diseases. Protein detection relies largely on antibodies, which have significant technical limitations especially when immobilised on two-dimensional surfaces. Here, we report the integration of peptide aptamers with extended gate metaloxide-semiconductor field-effect transistors (MOSFETs) to achieve label free sub-picomolar target protein detection. Specifically, peptide aptamers that recognise highly related protein partners of the cyclin-dependent kinase (CDK) family are immobilized on the transistor gate to enable human CDK2 to be detected at 100 fM or 5 pg/ml, well within the clinically relevant range. The target specificity, ease of fabrication and scalability of these FET arrays, further demonstrates the potential application of the multiplexable field effect format to protein sensing.