Research On Sensitization And Multiplexing Technology Of Optical Fiber Based Optofluidic Biosensor

Optofluidic biosensor technology is an important point-of-care testing(POCT),which can quickly and specifically detect specific marker molecules in biomedical samples,bringing fast and convenient technical means for early disease diagnosis and screening.For the diagnosis of cardio-vascular diseases,the detection of myocardial damage markers has become a necessary detection step.When the patient only has symptoms such as chest pain or even no obvious symptoms,the content of disease markers may have changed.Therefore,for the early diagnosis of cardiovascular disease,the sensor must have extremely high sensitivity to detect this change.At the same time,the abnormality of a single marker is difficult to truly reflect the condition of the disease,and it is necessary to carry out the three myocardial tests,that is,the detection of three typical myocardial injury markers at the same time can provide accurate and reliable diagnosis results.In response to the above requirements,this article is based on the organic fusion of microfiber and silicon capillary to develop sensitization and multiplexing technology research.The main work is as follows:(1)Research on sensitization methods.Theoretical research on the sensing mechanism of the fiber-tube optofluidic sensor has been carried out.It is found that the diameter of the microfiber and the thickness of the capillary tube wall have a decisive influence on the sensitivity of the sensor.Under the guidance of theoretical results,we have improved the fusion taper method experimen-tally and increased the sensor’s refractive index sensitivity to 1.6×10~4nm/RIU,which is an order of magnitude higher than the previous work.(2)Multiplexing technology research.With the microfiber interferometer as the sensitive element,a miniaturized,optofluidic biosensor multiplexing sensing system is constructed.Based on the time division multiplexing method,the joint detection of three typical myocardial injury markers is realized,and the interference of external noise is eliminated by introducing the reference channel to ensure the high accuracy of detection.The experimental results show that the detection concentration range of the system for three myocardial injury markers such as CK-MB,c Tn-I and Myo are 0.2～200 ng/mL,0.02～20 ng/mL and 0.5～500 ng/mL.