Detection of Endotoxin Concentration Using Piezoelectric Based Biosensor System

Endotoxins are ubiquitous in the environment and represent important pathogenic molecules. In this paper, we present a sensitive and reliable method for quantitation and detection of endotoxin based on piezoelectric biosensors, which monitor the gel formation (causing viscosity change) when Limulus Amoebocyte Lysate (LAL) mixed with endotoxin. The resonance frequency shifts of the sensors in contact with different concentration endotoxin were recorded as a function of time. Results showed that there has good relationship between the logarithmic concentration of endotoxin and the maximum clotting rate as well as the corresponding clotting time. The detection limits could be gone down to 0.1pg/ml and the time-consuming is about 1 hour using this system. By comparison of the traditional methods (rabbit pyrogen test and LAL test) for detection of endotoxin, the proposed sensor is much simpler, more precise and lower detection limits.