Every year, hundreds of livestock are killed or sickened by ingesting water contaminated with cyanotoxins. These toxins produce liver and neural damage and an increasing body of evidence suggests that they also accumulate in food chains. The issue of preventing livestock loss from harmful algal blooms is beset by two problems. First, toxins produced by blue green algal (so called cyanobacteria) blooms occur explosively and unpredictably, but do not always produce toxins. Second, the state-of-the-art approach in diagnosing waters contaminated by cyanobacteria is to collect water samples and send them to diagnostics laboratories for identification of algal species and for analysis by either enzyme-linked immunosorbent assay (ELISA) or liquid chromatography tandem quadrupole mass spectrometry (LC-MS/MS). Both analytical procedures are inherently slow processes, often requiring days to complete and require highly specialized personnel to conduct.

In the meantime, producers are left to make decisions regarding the safety of their water supplies without all of the information, resulting in some producers unnecessarily hauling water from outside sources. In addition, since not all cyanobacterial blooms produce toxins, technologies for the detection of cyanobacterial organisms do not accurately assess the risk associated with ingestion of the water. This project focuses on developing small, inexpensive sensors that producers can utilize to obtain quantitative measurements of the concentration of toxic microcystin.

State-of-the-art approaches to diagnosing waters contaminated by cyanobacteria is to collect water samples and send them to diagnostics laboratories for identification of algal species and for toxin analysis using either ELISA or LC-MS/MS techniques. In addition to the time associated with these tests, ELISA tests approximately cost $30 per assay whereas LC-MS/MS tests cost anywhere from $80 to $150 per assay. Our aim is to bring this cost down to approximately $10 per assay in addition to giving the producer results in minutes rather than days.

The long-term goal of this research is to develop a low-cost (~$10), fully integrated real-time CMOS sensor, the shape and size of a pen, which producers can dip into a questionable water supply to obtain quantitative measurements of toxin concentration that has the same level of accuracy as traditional laboratory-based methods. The first steps to achieving this goal will be to:

• Develop a working prototype impedance measurement unit compatible with capacitive biosensors
• Develop and electrical impedance spectroscopy-based electrode for Microcystin

This project has been made possible by the generous support of:

• United States Department of Agriculture under award 2015-67021-23128
• Iowa State University