Study of rapid endotoxin detection based on interdigital gold electrode and SAW

Objective To establish a method of rapid detection of bacteria endotoxin based on interdigital gold electrode and surface acoustic wave (SAW).Methods With the carriers of 3-APTES and glutaral pentanedial,Polymyxin B (PMB) was immobilized on interdigital gold electrode,and then reacted with the bacteria endotoxin' s biological active material (lipopolysacchride,LPS) selectively.Double differential circuit based on SAW was employed to complete the detection.Two output oscillation signals were differentiated through mixer and the endotoxin content was described by frequency shift.Results The experimental results indicated that there was a liner relationship between the frequency shift and endotoxin content within the content range of 75-130 EU/ml.Conclusion Comparing with traditional method,the detection time is shortened to 10 minutes,the sensitivity is 13.8 KHz/(EU·mL-1),and repeatability is above 90％. Key words: Endotoxin detection;  Interdigital gold electrode;  Surface acoustic wave;  Self-assembly