The University of Massachusetts Amherst
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UMass Research Team Creates Ultra-sensitive Ammonia Sensor with Many Agricultural, Environmental, and Biomedicine Applications

graphical representation of bioelectronic-ammonia-gas sensor

A team at UMass Amherst reports developing a bioelectronic-ammonia-gas sensor that is among the most sensitive ever made. The sensor, created by Biomedical Engineering Department doctoral student Alexander Smith (first author) with his advisor Jun Yao of the Electrical and Computer Engineering Department and Derek Lovely of the Microbiology Department, uses electric-charge-conducting protein nanowires derived from the bacterium Geobacter to provide biomaterials for electrical devices.

See News Office release and media coverage:,, AZO Sensors, News Medical Life Sciences, Genetic Engineering & Biotechnology News.

Smith says in a UMass News Office article that the research team designed its initial sensor to measure ammonia because that gas is important to agriculture, the environment, and biomedicine. For example, in humans, ammonia on the breath could signal disease. In poultry farming, the gas must be closely monitored and controlled for bird health and to avoid feed imbalances or production losses.

As Yao says, “This sensor allows you to do high-precision sensing; it’s much better than previous electronic sensors.”

Smith adds that “Every time I do a new experiment, I’m pleasantly surprised. We didn’t expect [the sensors] to work as well as they have. I really think they could have a real positive impact on the world.”

Smith says in the News Office release that existing electronic sensors often have either limited or low sensitivity and they are prone to interference from other gases.
In addition to superior function and low cost, Smith explains, “Our sensors are biodegradable so they do not produce electronic waste, and they are produced sustainably by bacteria using renewable feedstocks without the need for toxic chemicals.”

Smith, who calls himself “entrepreneurial,” won first place in UMass Amherst’s 2018 Innovation Challenge for the startup business plan for “e-Biologics,” the company he formed with Yao and Lovely. The researchers have followed up with a patent application, fundraising, business development, and research and development plans.

Support for the work came from a CAREER grant and Graduate Research Fellowship from the National Science Foundation (NSF), UMass Amherst’s Office of Technology Commercialization and Ventures, and the UMass Center for Hierarchical Manufacturing, an NSF-funded Nanoscale Science and Engineering Center. (June 2020)