SBIR Phase I: A Family of Sensor Dyes for Real-Time Optical Sensing of Metals in Aqueous Environments

This Small Business Innovation Research Phase I project seeks to refine, broaden and characterize a new family of optical chemosensor dyes designed for real-time monitoring and control of heavy-metal concentrations in industrial wastewater discharge. This will allow metal platers, metal finishers, circuit board manufacturers, ink manufacturers, and a multitude of other businesses that discharge heavy metal waste, the capability to reduce treatment costs by an average of 25% to 40%. At the same time, this technology will assist in improving compliance with discharge limits defined by the Environmental Protection Agency's Clean Water Act and by local regulatory agencies. This would in turn reduce toxic metal treatment costs at downstream municipal wastewater treatment plants. It is estimated from market surveys that at least 15,000 businesses in the United States are potential customers for such a system. The global market in this vertical is estimated to be at least $2 billion. In addition, many other market segments, such as defense and homeland security, could potentially use these chemosensor arrays to permit accurate detection of heavy metals in real-world conditions. The intellectual merit of this project is that it further develops and evaluates a family of chemosensor dyes that are inherently stable over time and can be used for continuous, real-time, heavy-metal monitoring in wastewater treatment processes with detection limits relevant to environmental regulations. Earlier work demonstrated that sets of several of these dyes have significant promise to accurately and continuously measure the concentration of specific metals in wastewater effluent. To quantify each metal ion of interest, the output of multiple dyes is analyzed to provide accurate identification of specific metals. Rigid attachment to the sensing platform allows for longer-term deployment. Specifically, this project intends to demonstrate and evaluate the response of a sensor array to several heavy metals identified, based on customer surveys, as the primary analytical needs of the wastewater industry. This effort will include the quantification of relevant metal ions and an evaluation of the stability of those measurements over time in several flow systems which will be assembled. A viable sensing platform prototype is envisioned at the end of a successful project. Moving forward, further dyes can be added to allow quantification of other metals over the concentration ranges of interest, with minimal interference.