Research On Electrochemical Immunosensor For Detection Of Lung Cancer Exosomes And Development Of Prototype

Exosomes are small（30-150 nm）membranous vesicles.Studies have found that the content of exosomes is related to the tumor formation and development stage,which can be used as a diagnostic marker.The common methods for quantitative detection of exosomes are complex,with results not specific for cancer.Herein,we present a tri-channel electrochemical immunobiosensor for detecting carcino-embryonic antigen（CEA）,neuron-specific enolase（NSE）and cytokeratin19 fragments（Cyfra21-1）from exosomes for specific early diagnosis of lung cancer,and developed an electrochemical immunoassay instrument,which can realize the automatic detection of exosomes.The electrochemical immunobiosensor real-time detection system was developed based on the designed detection chip,which is suitable for outpatient department and emergency department.The main research work and achievements of this study are as follows:1.Based on the principle of electrochemical immunosensor detection,an array electrochemical immunosensor was designed and manufactured to realize joint detection of multiple markers and micro,integrated detection.The effects of reference electrode materials and electrolyte on electrochemical detection signals were studied to provide a basis for subsequent detection of exosomes.2.The electrochemical detection experimental platform was built to study the effects of concentration and fixation time of antibody on the detection signal.The detection performance of the immunosensor for carcinoembryonic antigen（CEA）,neuron specific enolase（NSE）and cytokeratin 19 fragment（Cyfra21-1）was characterized and analyzed.The linear detection ranges were 10^-3～10 ng/ml,10^-4～10²ng/ml and 10^-3～10²ng/ml respectively,and the detection limit was less than 10-4ng/ml.3.The cell culture experimental platform was built to realize the culture of lung adenocarcinoma,lung squamous cell carcinoma and small cell lung cancer cells.The combined detection of exosome markers in cell supernatant showed that there were significant differences in the expression levels of exosome markers in different lung cancer cells.4.Based on the electrochemical detection chip,an electrochemical detection prototype of exosomes was developed.The mechanical structure and layout of the device,hardware circuit and PCB design,software design of the lower computer were designed in detail,and the performance of signal generation and acquisition,electrochemical detection were tested.The detection results have good linear correlation,which can basically meet the needs of rapid detection.