Skip to main content


Multidisciplinary Sensor Development


IGERT student Eric Roy’s research on developing a sensor to measure trace amounts of metal in seawater has lead to a new four-year National Science Foundation grant. The project has been a real success story in interdisciplinary research. Roy’s co-advisors, professors Mark Wells (Marine Science) and Carl Tripp (Chemistry) of UMaine and his undergraduate advisor Whitney King of Colby College are extending the collaboration that was sparked by Roy’s research. The research challenge is to measure iron at extremely low levels and not in a lab but in the open ocean. Iron in the open ocean occurs a very low levels. As Wells said, “It is comparable to measuring a drop of food coloring added to an Olympic-size pool”. The process now used to measure iron and copper requires collecting samples individually from large research vessels and analyzing them in a laboratory, an expensive and time consuming process. Roy, fellow doctoral graduate Cuihong Jung, Wells and Tripp have spent the past three years developing a nanostructured surface technology. The sensor is a 1- centimeter-by-1-centimeter film of an organic molecule made from bacteria. The film binds with iron from seawater and allows scientists to analyze iron levels. The researchers tested the film over the past few years in the Gulf of Alaska, which is known to have particularly low iron levels. The current system has a detection limit of 50 pM for a 1-L sample at pH 1.7 and can measure dissolved iron without interference from other elements in seawater. The new research will work to refine the sensing surface so it can be incorporated into a prototype device for use on ocean-observing platforms. The researchers also are hoping to miniaturize the whole system, which is now the size of a steamer trunk, to the size of a shoebox or even a cell phone. “Until recently, we were a very long way away from developing such a sensor,” said Wells. It’s a major jump forward in trying to analyze things found in ocean waters."

Being able to obtain precise measurements of iron and copper in seawater is important in understanding the growth of phytoplankton, the tiny oceanic plants that serve as the foundation of marine ecosystems. Iron and copper are important for sustaining phytoplankton. Additionally phytoplankton sequester carbon dioxide, the predominant greenhouse gas responsible for global warming. Scientists who model climate change examine phytoplankton levels in the ocean because they have found that the more phytoplankton, the lower the levels of carbon dioxide. Low levels of iron would indicate low levels of phytoplankton. Thus access to more frequent and precise measurements of iron can help to better estimate how much carbon dioxide phytoplankton can sequester.

Address Goals

The project illustrates the power of interdisciplinary research and training. The interdisciplinary interaction was key to better understanding the problem and formulating a solution; an outcome much less likely to have been achieved or achieved as quickly with a single disciplinary perspective.