U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Nanowire pH Sensor for Biological Applications
Published: January 05, 2012
Posted: March 07, 2012

A cell's internal and external pH plays a critical role in influencing many cellular chemical reactions and functions. Yet measuring pH without the appearance of artifacts in these challenging cellular and extracellular nanoscale environments is very difficult. New silicon nanowire (SiNW) pH sensors that possess long-term stability in these difficult environments have been developed by scientists at Lawrence Berkeley National Laboratory and their collaborators. The sensors were produced using a top-down fabrication process combining electron beam lithography (EBL) with conventional photolithography. A passivation layer (silicon nitride applied using plasma enhanced chemical vapor deposition) is coated on the SiNW's surface to enhance electrical insulation and ion-blocking properties. This study shows that the application of these techniques results in improved stability of the sensor and enhances its performance. The paper explains how to achieve reliable performance in biological systems and discusses the trade-off between stability and pH sensitivity of the sensor response.

Reference: Choi, S., I. Park, Z. Hao, H.-Y. Holman, and A. P. Pisano. 2012. "Quantitative Studies of Long-Term Stable, Top-Down Fabricated Silicon Nanowire pH Sensors," Applied Physics A: Materials Science & Processing, DOI: 10.1007/s00339-011-6754-9. (Reference link)

Contact: Arthur Katz, SC-23.2, (301) 903-4932
Topic Areas:

  • Research Area: Research Technologies and Methodologies

Division: SC-23.2 Biological Systems Science Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)