Disposable, Digital Phosphate Sensor



Drinking water treatments, Waste water treatments, Aquaculture operations, Aquariums, Analytical and Pharmaceutical laboratories, Fertilizers industry etc.

Target Problems

  • Increased levels of phosphate can lead to eutrophication, low oxygen in waterways that can severely affect aquatic life, and toxic algal blooms.
  • The EPA approved method for measuring phosphates involves the use of chemical reagents.
  • In some cases, samples must be brought back to the lab for analysis.


Inventors at UW-Milwaukee (UWM) have developed a highly sensitive, digital, graphene based electrochemical sensor for the detection of phosphate in water. The sensor is designed to detect phosphate levels as low as 10-10 M (mol/L) using layers of graphene oxide, polypyrrole and metal. It is specific and can avoid interference from potassium chloride present in the solution.

Phosphate is a well-known contaminant of water which in excess leads to eutrophication, or an excess of nutrients in the water. The UWM phosphate sensor is easier to use and more sensitive compared to other reported devices, many of which focus on a colorimetric assay. It uses a simple digital potential readout through a voltmeter rather than voltammic stripping. The system can be hand held for mobility or mounted as a semi-permanent device. Positive test results have shown that, this device can provide an accurate and inexpensive alternative to the current products on the market.

Features and Benefits

  • Highly Sensitive – Detects phosphate levels as low as 10-10 M (mol/L), several orders of magnitude lower than other devices.
  • Low Cost – The material used are readily available and only a voltmeter is needed for detection
  • Disposable and Easy-to-Use – Sensors can be fabricated for one time use for quick and easy set-up. Can be hand held or mounted.
  • Pre-Calibrated and Quick – Sensors can be supplied pre-calibrated that can save time.
  • Multiple Applications – Residential, industrial, environmental, governmental and research use.

Intellectual Property

US Patent Pending, US20200158682A1

This technology is part of an active and ongoing research program and is seeking partners for development of the final product. It is available for developmental research support/licensing.

Sensors available for testing, collaborative opportunities, and licensing. Not for individual sales and/or testing

Inventor (s)