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

• DOI: 10.1039/c2an15930a
• Publication Date: 2012-01-19T13:31:31Z
• Authors: Grace M. Credo; Xing Su; Kai Wu; Oguz H. Elibol; David J. Liu; Bobby Reddy; Ta-Wei Tsai; Brian R. Dorvel; Jonathan S. Daniels; Rashid Bashir; Madoo Varma
• Keywords: Silicon; SENSOR ARRAYS; Transistors, Electronic; Surface Properties; Molecular Sequence Data; Biosensing Techniques; DNA-Directed DNA Polymerase; DIAGNOSTICS; EFFECT TRANSISTORS; SENSOR ARRAYS; AMPLIFICATION; BIOSENSORS; BIORECOGNITION; HYBRIDIZATION; SPECTROSCOPY; DIAGNOSTICS; MOLECULES; EMULSION; 01 natural sciences; MOLECULES; Chelating Agents; SPECTROSCOPY; Base Sequence; Molecular Structure; EFFECT TRANSISTORS; AMPLIFICATION; DNA; Electrochemical Techniques; Silanes; 540; Nanoscience and Nanotechnology; 0104 chemical sciences; Diphosphates; BIOSENSORS; BIORECOGNITION; HYBRIDIZATION; EMULSION

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.