BER launches Environmental System Science Program. Visit our new website under construction!

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-33.2 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

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)