Surface-modified silicon nano-channel for urea sensing

Silicon nano-channels have been surface functionalized with the enzyme urease for biosensor applications to detect and quantify urea concentration. The device is nanofabricated from a silicon-on-insulator (SOI) wafer with a top down lithography approach. The differential conductance of silicon nano-channels can be tuned for optimum performance using the source drain bias voltage, and is sensitive to urea at low concentration. The experimental results show a linear relationship between Surface potential change and urea Concentration in the range of 0.1-0.68 mM. The sensitivity Of Our devices shows high reproducibility with time and different measurement conditions. The nano-channel urea biosensor offers the possibility Of high quality, reusable enzyrne sensor array integration with silicon-based circuits. (C) 2008 Elsevier B.V. All rights reserved.