Real-time, continuous and quantitative detection of bioavailable radionuclides and heavy metals in contaminated water at DOE sites

Quantitative, real-time detection of hazardous metal ions on-site is an important goal and remains a significant challenge while monitoring sources such as potable, ground, surface and industrial waters. Quantitative analysis of trace elements is predominantly done by sending the samples to a laboratory for testing by sophisticated analytical techniques, such as Inductively Coupled Plasma Spectrometry which can be time consuming ( & gt; 2 weeks) and expensive. A few spot test kits are available; however they often consist of complex laboratory type operations which are prone to interferences, are generally specific to one inorganic contaminant, and generally require an experienced laboratory technician. To reduce the need for human interaction, a few continuous monitors have been offered in the market but because the technology remains the same, the equipment is expensive, prone to issues and requires proper disposal of hazardous chemical samples and reagents. This limits the monitoring of water sources to those which have the highest risks or fines associated with them. Our company (ANDalyze Inc.) has licensed the fluorescent DNAzyme technology from the University of Illinois and commercialized sensors for uranium, lead, copper and mercury for application in detection of heavy metals in drinking water. Through a combinatorial biological technique called in vitro selection, we have obtained catalytic DNAs that are highly specific for a given metal ion. These DNAs have been transformed into fluorescent sensors by labeling the DNA with a fluorophore and quencher. By using a handheld fluorimeter and the specific sensor, we can measure the fluorescence levels of a sample to extrapolate the corresponding level of metal. We propose to develop on-site, real-time continuous monitor devise for detection and quantification of hazardous metals at concentrations below EPA limits in water matrices such as potable, ground, surface and industrial waters, while generating minimal, non-hazardous waste. It will allow for unattended operations for up to 30- days, while measuring water samples for a specified metal at a frequency as low as 2 minutes and as low. The design will utilize a novel catalytic DNA (DNAzyme) based fluorescent biosensors for effective detection and quantification of hazardous metals such as lead, uranium, zinc, cadmium, chromium, arsenic and selenium. We will demonstrate the feasibility of this approach by making a prototype continuous monitoring equipment and testing its utility with DNAzyme based sensor for uranium.