Pao Chang, “Fabrication of Screen-Printed Electrodes for Detection of Phosphate”
Mentor: Woo Jin Chang, Mechanical Engineering, Engineering & Applied Science (College of)
Poster #42
The intention of this research is to further understand the detection capabilities of modified screen-printed electrodes (SPE) for phosphate from a previous study. Phosphorus is essential to life, mainly in the form of organophosphates. This research method utilizes an already commercially available sensor which is then modified chemically for our purpose. Equipment used includes Zensor TE100Screen printed electrode, beaker, micropipette, and CH Instruments Electrochemical Analyzer. Materials and chemicals used includes Ammonium Molybdate (AM), Pyrrole (Py), Sodium Phosphate Monobasic, Sodium Phosphate Dibasic, Sulfuric Acid (H2SO4), Deionized (DI) water and Ethanol for cleaning. Fabrication of the sensor required cleaning as the primary modification. After cleaning, a mixture of the prepared buffer solution and fabrication solution (NaH2PO4 and Na2HPO4) in equal volume was used to modify the surface of the sensor via a drop-cast method. The solution was allowed to absorb and dry for 24 hours before testing. Testing for Phosphate was conducted using CH Instruments Electrochemical Analyzer Open Circuit Potentiometry (OCP) technique. Modification of the sensor contained many variables and all sensors were modified using one protocol. However, sensors were unable to produce consistent and significant results. In prior research, researchers were able to obtain consistent results and trends in NaH2PO4 Standard Solution with a concentration range of 10-7 to 10-11 (mol/L). In this research, a baseline concentration (10-5 mol/L) was tested to verify sensor viability. Additional different concentrations are to be tested in the future. Recreation of the phosphate sensor research remains a work in progress and there exists many variables and parameters that are to be tested yet. Testing outside of established parameters yields results that do not correlate with known research data and additional testing is required. Ultimately, there is high potential for detection of phosphate in various ranges once parameters and variability can be further narrowed down.