The broader impact/commercial potential of this I-Corps project is the development of inexpensive and reliable sensors to monitor multiple water quality parameters - pH, phosphate levels, and the heavy metals dissolved in water. These sensors are easy to use, portable, and can provide rapid test results. Most of the current technologies require water sample collection from sites, followed by tests in external labs. This technology can be used for residential and industrial applications. It can be used for monitoring water quality in swimming pools, residential and commercial aquariums, agricultural water run-off, water body with algae bloom, houses known to have lead service lines, industrial effluent, and breweries. Additionally, longer term development of the technology may enable integration with a plumbing system/water filtration system for automated monitoring and added reliability. <br/><br/>This I-Corps project has developed an electrochemical sensor using a screen-printed electrode modified with different functional nanomaterials to detect concentrations of dissolved heavy metals, phosphate and pH in water. In addition to graphene, functionalized nanomaterials and conducting polymer nanocomposites deposited on the electrode surface are a reliable approach to enhance the selectivity and affinity of target molecules of analysis. The nanocomposite materials include reduced graphene oxide and polypyrrole to increase the electron transfer and electrode?s surface area. The functional materials for the target molecules of pH, phosphate, and heavy metals are iridium oxide, molybdate, and cysteine, respectively. By observing the potentiometric and amperometric change occurring in the electrochemical reaction at the electrode-solution interface, quantitative and qualitative evaluations of the relevant substance in water are possible.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.