Hybrid synthetic receptors on MOSFET devices for detection of prostate specific antigen in human plasma

The study reports the use of extended gate field-effect transistors (FET) for the label-free and sensitive detection of prostate cancer (PCa) bio-markers in human plasma. The approach integrates for the first time hybrid synthetic receptors compris-ing of highly selective aptamer-lined pockets (apta-MIP) with FETs for sensitive detection of prostate specific antigen (PSA) at clinically relevant concen-trations. The hybrid synthetic receptors were con-structed by immobilising an aptamer-PSA complex on gold and subjecting it to 13 cycles of dopamine electropolymerisation. The polymerisation resulted in the creation of highly selective polymeric cavities that retained the ability to recognize PSA post removal of the protein. The hybrid synthetic receptors were subsequently used in an extended gate FET setup for electrochemical detection of PSA. The sensor was reported to have a limit of detection of 0.1 pg/ml with a linear detection range from 0.1 pg/ml to 1 ng/ml PSA. Detection of 1-10 pg/mL PSA was also achieved in diluted human plasma. The present apta-MIP sensor developed in conjunction with FET devices demonstrates the potential for clinical application of synthetic hybrid receptors for the detection of clinically relevant biomarkers in complex samples.