Surface modified silicon nanochannel for urea sensing

TL;DR

This paper presents a silicon nanowire biosensor functionalized with urease enzyme for sensitive, reproducible urea detection, demonstrating a linear response at low concentrations suitable for integration with silicon circuits.

Contribution

Development of a surface-modified silicon nanowire biosensor with tunable conductance for accurate urea detection, showing high reproducibility and potential for integration into silicon-based sensor arrays.

Findings

Linear urea detection range of 0.1 to 0.68 mM

High reproducibility over time and conditions

Sensitive to low urea concentrations

Abstract

Silicon nanowires 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 nanowires 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 to 0.68 mM. The sensitivity of our devices shows high reproducibility with time and different measurement conditions. The nanowire urea biosensor offers the possibility of high quality, reusable enzyme sensor array integration with silicon based circuits.