Project Description
Task I. Microfluidic Electrochemical System for PFAS Detection in drinking water (PI: Kim): A microfluidic electrochemical flow cell system offers a portable and highly sensitive platform for real-time PFAS detection from liquid soil extracts and drinking water. Building on prior studies, the PIs have developed an electrochemically induced PFAS sensing strategy that incorporates fluorinated molecular acceptors (FMAs) for PFAS quantification, as illustrated in Figure 1a. Currently, the PI Kim has been focused on the enhancement of high EIS sensitivity for quantifying trace levels of PFAS with one PhD student. In collaboration, the Kim and Leem research groups have designed a microfluidic electrochemical flow cell incorporating an FMA-coated mesoporous structured working electrode (WE) and a platinum cathode (Figure 1b). In 2026, an operable microfluidic electrochemical flow cell will be demonstrated for accurate measurement of PFAS concentrations in drinking water.
Figure 1. Schematic illustration of (a) a portable, time-sensitive and regulatory-approved PFAS sensor and (b) drawing of microfluidic electrochemical flow cell system.
Task II. Fabrication of mesoporous structured electrodes and screening printing (PIs: Leem and Yoo): ask II focuses on the fabrication of mesoporous structured macroelectrodes based on fluorine-doped tin oxide (FTO) and tin-doped indium oxide (ITO) for electrochemical quantification of PFOA and PFOS in drinking water. Planar FTO and ITO electrodes of consistent and well-defined quality are commercially available and serve as reliable substrates for sensor development.
Figure 2. SEM images of (a) polystyrene latex beads and (b) mesoporous structured ITO/FTO electrodes as an anode. (c) XPS spectra confirming In and Sn on mesoporous ITO/FTO electrodes..
The Leem and Yoo research have successfully fabricated high–surface area mesoporous ITO and FTO electrodes, as shown in Figure 2. Polystyrene (PS) latex beads were synthesized via emulsion polymerization, yielding homogeneous particles with average diameters of approximately 300–400 nm (Figure 2a). These PS beads act as sacrificial templates, enabling the formation of mesoporous ITO films following high-temperature annealing (>400 °C). Indium oxide (In₂O₃) nanoparticles were prepared using a solvothermal method and incorporated into mesoporous oxide films. These conductive metal oxide macroelectrodes offer key advantages for sensing applications, including tunable pore size, controllable film thickness, and adjustable morphology. Mesoporous films were deposited using a doctor-blade technique with spacers to ensure uniform thickness, followed by sintering at 450 °C to generate mechanically stable and conductive mesoporous electrodes (Figure 2b). X-ray photoelectron spectroscopy (XPS) confirmed the presence of indium and tin, verifying the formation of conductive ITO/FTO layers (Figure 2c). To enhance scalability, patterning, reproducibility and control of the film thickness on the macroelectrode, surface-screen printing will be employed in 2026.