Rapid mass transfer of analytes is essential for effective electrochemical sensing. Here, we present a vibrating air bubble as a stirrer and evaluate the optimal working frequency. A vibration system that contains a flexible piezoelectric plate coupled with a trapped bubble integrated with a gold working electrode is employed. The vibrational properties and mass transfer of the coupled system are experimentally tested with optical and electrochemical methods, respectively. Streaming flows generated by the vibrating bubble are characterized by visualization to explain the enhancement of mass transport to the working electrode. Compared with a static case, measurements with a vibrating bubble demonstrate a twelve-times enhancement in mass transfer coefficient. Enhanced sensing performance is experimentally quantified with the bubble stirrer and its integrated electrochemical metal ion sensor. This integrated system can be used for various types of electrochemical sensing applications that are limited by slow molecular diffusion.
Bibliographical noteFunding Information:
Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under Award Number ECCS-2025124 . This work was partially sponsored by Environment and Natural Resources Trust Fund (ENRTF) funding through Legislative-Citizen Commission on Minnesota Resources (LCCMR) in Minnesota State.
© 2021 Elsevier B.V.
- Anodic stripping voltammetry
- Electrochemical sensor
- Mass transfer
- Streaming flow
- Vibrating air bubble