Love Mode Surface Acoustic Wave and Impedance Sensors for Water Toxicity Sensing

摘要

Clean water supply systems and infrastructure require periodic testing of water samples to maintain water quality. To enable this, toxicity tests need to be rapid, accurate, portable, and low cost to provide affordable water security especially in developing countries. Qualitative and quantitative measurement of contaminants in water is classically done by standard analytic chemical methods, which are time-consuming, labor-intensive, expensive, and cannot be performed easily outside the laboratory. An alternative to these methods is cell-based sensors, which can detect the presence of a wide range of toxicants by monitoring the cell states. Although electric cell-substrate impedance sensing (ECIS) has been demonstrated to be an effective method for water toxicity sensing, the use of ECIS only is not sensitive enough to detect many toxicants at low concentrations. Merging a sensor platform with multiparametric measurement capabilities could increase the security of detection. Love mode surface acoustic wave (SAW) device is considered as one of the powerful candidates for cell-based toxicity biosensors. In this study, a hybrid Love mode SAW/ECIS sensor was developed. Theoretical analysis and experiments were performed to demonstrate the capability of two sensing techniques (i.e., SAW and ECIS) for toxicity sensing.