High-Sensitivity MEMS Resonant Biosensor for Monitoring Water Toxicity

This paper presents the use of a piezoelectric resonator, which can be applied to investigate live cells activity in water-based toxic solution. We perform toxicity tests using commercial quartz crystal microbalance (QCM). The QCM used in this research has the resonant frequency of 10 MHz and consists in an AT-cut crystal with gold electrodes on both sides. This QCM was transformed into a functional biosensor by integrating with polydimethylsiloxane (PDMS) culturing chambers. Rainbow trout gill epithelial cells (RTgill-W1) were cultured on the resonators as sensorial layer. The fluctuation of the resonant frequency, due to the change of cell morphology and adhesion, is an indicator of water toxicity. The shift of resonant frequency will provide information about the cells viability after exposure to toxicants. Experiment setup, fabrication process, and sensor sensitivity testing are addressed. The toxicity result shows distinct responses for different ammonia concentrations.