Mass-based Techniques
An example of mass-based techniques is electromagnetic piezoelectric acoustic sensors, or EMPAS that has been touted as being able to measure multiple types of pathogens, not exclusively endotoxins, as well as being able to detect endotoxins in real time within human blood plasma 108. Another mass-based method is magnetoelasticity that function by placing sensors directly on to dry testing surfaces, such as medical equipment or food. The sensor filaments, whose oscillation frequencies are monitored, fluctuate within a magnetic field. These sensors are coated in phages designed to bind with the target pathogen, like ENPs 109. Then under an applied magnetic field, the sensors will oscillate differently than before the test, due to the increase in mass from the newly-bound endotoxin. The change in mass is measured similar to EMPAS testing. This method has a reported detection limit of 0.0105 EU/mL, or close to 0.001 ng/ml, and a detection time of nearly 5 minutes.