Rensselaer researchers to build biosensor capable of measuring critical nutrients in water The surface of a pristine, transparent freshwater lake may not reveal to ecologists the reality of what’s occurring in its depths. Evaluating the cumulative effects of climate change, pollutants, acidification, or invasive species requires more precise methods. But even the most dynamic and sensitive sensors commonly used today are not always able to tell researchers what they need to know. Engineers at Rensselaer Polytechnic Institute are teaming up with an unexpected ally – a metal-breathing bacterium called Shewanella oneidensis MR1 (S. oneidensis) – to try to dramatically improve biosensors for freshwater and marine aquatic ecosystems.