Electrochemical Filtration of Gadolinium from Patient Urine after Magnetic Resonance Imaging.

The widespread use of gadolinium-based contrast agents for magnetic resonance imaging (MRI) in recent decades has led to a growing demand for Gd and raised environmental concerns due to their direct discharge into wastewater systems. In response, we developed an electrochemical filtration method to recover Gd from patient urine following contrast-enhanced MRI. This method involves modifying a conventional vacuum filtration apparatus by introducing electrodes into the filter membrane, creating a strong electric field of ∼5 kV/m and a steep three-zone pH gradient within the filter membrane.

Highly efficient preconcentration using anodically generated shrinking gas bubbles for per- and polyfluoroalkyl substances (PFAS) detection.

Here we report a highly efficient PFAS preconcentration method that uses anodically generated shrinking gas bubbles to preconcentrate PFAS via aerosol formation, achieving ~ 1400-fold enrichment of PFOS and PFOA-the two most common PFAS-in 20 min. This new method improves the enrichment factor by 15 to 105% relative to the previous method that uses cathodically generated H bubbles. The shrinking gas bubbles are in situ electrogenerated by oxidizing water in an NHHCO solution.

Harnessing bubble behaviors for developing new analytical strategies.

Gas bubbles are easily accessible and offer many unique characteristic properties of a gas/liquid two-phase system for developing new analytical methods. In this minireview, we discuss the newly developed analytical strategies that harness the behaviors of bubbles. Recent advancements include the utilization of the gas/liquid interfacial activity of bubbles for detection and preconcentration of surface-active compounds; the employment of the gas phase properties of bubbles for acoustic imaging and detection, microfluidic analysis, electrochemical sensing, and emission spectroscopy; and the application of the mass transport behaviors at the gas/liquid interface in gas sensing, biosensing, and nanofluidics.

Bubble-Nucleation-Based Method for the Selective and Sensitive Electrochemical Detection of Surfactants.

We present the first bubble-nucleation-based electrochemical method for the selective and sensitive detection of surfactants. Our method takes advantage of the high surface activity of surfactant analyte to affect the electrochemical bubble nucleation and then transduces the change in nucleation condition to electrochemical signal for determining the surfactant concentration. Using this method, we demonstrate the quantitation of perfluorinated surfactants in water, a group of emerging environmental contaminants, with a remarkable limit of detection (LOD) down to 30 μg/L and a linear dynamic range of over 3 orders of magnitude.

Highly efficient hydrogen evolution of platinum via tuning the interfacial dissolved-gas concentration.

A facile perfluorooctanesulfonate (PFOS)-modulation strategy was developed to precisely control the dissolved-gas concentration at the electrode/gas/electrolyte interface for enhanced HER. With PFOS modulation, lowered dissolved-hydrogen concentrations at the catalytic interface and sufficient exposure of the surface active area can be achieved. Accordingly, relative to pure Pt, PFOS-modulated Pt possesses a remarkable HER performance.