Rice University scientists who say biological sensors aren't sensitive enough are doing something about it.

The lab of synthetic biologist Jeffrey Tabor has introduced a new technique to dial up or down the sensitivity of two-component systems - a class of proteins that bacteria use to sense a wide variety of stimuli.

The technique could enable the engineering of tailor-made biosensors for diagnostic gut bacteria, detection of environmental pollutants or automated control of nutrient levels in soil.

Two-component sensors, the focus of a new paper describing the work in Nature Communications, are a large family of genetically encoded sensors that bacteria use to sense a specific input and turn on a specific gene in response to changes in their environment.

Previous research had shown that mutations to the first component, a signaling sensor protein known as a histidine kinase, can be used to control the extent of phosphorylation of the second component, a response regulator protein.

One day, faced with a nitrate sensor that was not turning on as expected in the gut of a sick mouse, Landry hypothesized that phosphatase mutations might dramatically increase the pathway's sensitivity.