Low-Cost Biopolymer-Metal Sensor for Onsite Detection of Heavy Metal Ions

Abstract

Researchers at the University of Central Florida have developed an inexpensive, reliable sensor that can rapidly and simultaneously detect traces of multiple heavy metals in water. With its unique biopolymer-metal composite thin film, the device provides improved sensitivity for identifying toxins in situ, including mercury, cadmium, arsenic, chromium, thallium, lead and zinc.

As part of the technology development, the researchers also invented a novel fabrication process to produce the new composite film. Manufacturers can use the process to reduce costs significantly. With existing fabrication methods, an electrode (microsensor) can cost hundreds of dollars. In contrast, the UCF method provides an electrode with an estimated cost of less than $1. As an example, the technology offers the capability to develop an instrument that easily connects to a kitchen faucet to monitor heavy metal ions in drinking water.

Technical Details

The invention comprises a sensing device and a method for fabricating the device. A key aspect of the technology is a novel and simple electrodeposition method in which a metal ion and a polysaccharide form an integrated biopolymer-metal composite film. The process is more cost-effective than photolithography or physical deposition. It produces an electrode suitable for use aquatically to monitor the concentration of heavy metal ions or for in situ analysis of leachate heavy metal ions in water. Examples of metal ions used to make the composite film are iron (Fe), copper (Cu), or bismuth (Bi). Polysaccharide examples include chitosan or chitin.

In one example application, the researchers created two biopolymer-metal composite film-based sensors: one made of Bi-chitosan and another made of Fe-chitosan. Using the sensors with square-wave anodic stripping voltammetry (SWASV), the researchers simultaneously analyzed concentrations of heavy metals in real mining wastewater. They used the Bi-based composite film sensor to detect cadmium (Cd2+) and lead (Pb2+), and the Fe-based composite to detect arsenic (As3+). The detection limits observed in parts per billion (ppb) were 0.5 of Cd, 1 of Pb, and 3.75 of As.

Partnering Opportunity

The research team is looking for partners to develop the technology further for commercialization.

Stage of Development

Prototype available.

Benefit

Market Application