Browsing by Author "Villagran, Dino"

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    Electrochemical sensing of PFAS using gold nanoparticle functionalized electrodes
    (2025-03-04) Villagran, Dino; Westerhoff, Paul; Calvillo Solis, Jonathan Josue; Wong, Michael; Rice University; Board of Regents, The University of Texas System; Arizona Board of Regents on Behalf of Arizona State University; United States Patent and Trademark Office
    A method of electrochemical sensing includes providing an electrochemical sensor comprising a glassy carbon substrate and gold nanoparticles located on a surface of the glassy carbon substrate; and sensing electrochemically a compound selected from the group consisting of polyfluoroalkyl compounds or perfluoroalkyl compounds using the electrochemical sensor. PFOA quantification was performed by Square Wave Adsorptive Cathodic Stripping Voltammetry (SW-AdCSV) in test solutions with a 100-5,000 ppt concentration. The concentration has a linear relationship with the stripping current within this range. Analysis of tap and groundwater samples performed by additions method demonstrated precision and accuracy above 95%. These electrodes show stability throughout 200 cycles, and reproducibility across similarly prepared but different electrodes above 97.5%. Providing the electrochemical sensor can include providing at least one member selected from the group consisting of perfluoro-1-octanethiol (PFTO), 2,2,2-trifluoroethanethiol (TFET) or perfluorodecanethiol (PFDT) on the surface of the glassy carbon substrate.
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    Utilizing the broad electromagnetic spectrum and unique nanoscale properties for chemical-free water treatment
    (Elsevier, 2021) Westerhoff, Paul; Alvarez, Pedro J.J.; Kim, Jaehong; Li, Qilin; Alabastri, Alessandro; Halas, Naomi J.; Villagran, Dino; Zimmerman, Julie; Wong, Michael S.; Chemical and Biomolecular Engineering; Civil and Environmental Engineering; Electrical and Computer Engineering; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment
    Clean water is critical for drinking, industrial processes, and aquatic organisms. Existing water treatment and infrastructure are chemically intensive and based on nearly century-old technologies that fail to meet modern large and decentralized communities. The next-generation of water processes can transition from outdated technologies by utilizing nanomaterials to harness energy from across the electromagnetic spectrum, enabling electrified and solar-based technologies. The last decade was marked by tremendous improvements in nanomaterial design, synthesis, characterization, and assessment of material properties. Realizing the benefits of these advances requires placing greater attention on embedding nanomaterials onto and into surfaces within reactors and applying external energy sources. This will allow nanomaterial-based processes to replace Victorian-aged, chemical intensive water treatment technologies.