Label-free electrical detection of pyrophosphate generated from DNA polymerase reactions on field-effect devices

Grace M. Credo, Intel Corporation
Xing Su, Intel Corporation
Kai Wu, Intel Corporation
Oguz Elibol, Birck Nanotechnology Center, Purdue University; Intel Corporation
David J. Liu, Intel Corporation
Bobby Reddy Jr., University of Illinois Urbana-Champaign
Ta-Wei Tsai, Intel Corporation
Brian R. Dorvel, University of Illinois Urbana-Champaign
Jonathan S. Daniels, Intel Corporation
Rashid Bashir, University of Illinois Urbana-Champaign
Madoo Varma, Intel Corporation

Abstract

We introduce a label-free approach for sensing polymerase reactions on deoxyribonucleic acid (DNA) using a chelator-modified silicon-on-insulator field-effect transistor (SOI-FET) that exhibits selective and reversible electrical response to pyrophosphate anions. The chemical modification of the sensor surface was designed to include rolling-circle amplification (RCA) DNA colonies for locally enhanced pyrophosphate (PPi) signal generation and sensors with immobilized chelators for capture and surface-sensitive detection of diffusible reaction by-products. While detecting arrays of enzymatic base incorporation reactions is typically accomplished using optical fluorescence or chemiluminescence techniques, our results suggest that it is possible to develop scalable and portable PPi-specific sensors and platforms for broad biomedical applications such as DNA sequencing and microbe detection using surface-sensitive electrical readout techniques.

Discipline(s)

Nanoscience and Nanotechnology