A Terahertz Metamaterial Sensor For The Detection Of Lung Cancer Markers

Lung cancer has the highest incidence and fatality rate in the world today because it is asymptomatic and difficult to detect in its early stage.How to accurately detect lung cancer has always been a complex problem.However,it is a valuable method to detect and diagnose lung cancer by detecting the level of lung cancer markers.Squamous cell carcinoma antigen（SCCA）concentration level is an essential auxiliary index for lung cancer detection and diagnosis.However,conventional SCCA detection methods have problems,such as high cost,low efficiency and poor stability.In addition,because the standard reference value of SCCA is less than 1.5 ng/m L,the traditional method has a poor detection effect and cannot achieve specific detection.Because terahertz waves have the advantages of low energy and no ionizing radiation,they have essential application value in biomedical detection.In this paper,a terahertz metamaterial sensor is designed to detect the concentration of SCCA.The main innovation is to modify the surface of the sensor with alloxite nanotubes（HNTs）to improve the detection sensitivity,and to realize the specific detection of SCCA by using the antibo-antigen binding principle.Specific work is as follows:（1）The basic theory and performance indexes of the terahertz metamaterial sensor were studied,and a double-splitting ring terahertz metamaterial sensor with a sensitivity of 103GHz/RIU was designed.The sample was produced by micro-nano processing technology.By using terahertz time-domain spectroscopy test and scanning electron microscopy characterization,the actual condition of the sample is basically consistent with the simulation results.（2）The effects of HNTs modification with different concentrations on the performance of the sensor were studied.Firstly,the sensor performance of the unmodified HNTs sensor is tested.The results show that the resonant peak has no obvious frequency shift in the 1pg/m L-100 ng/m L SCCA concentration range,and the sensor sensitivity is only 0.83GHz/lg C_SCCA（ng/m L）.Then,the surface of the sensor was modified with five concentrations of HNTs.As the concentration of HNTs increased from low to high,the sensitivity of the sensor first increased and then decreased,and the sensitivity reached the highest when the concentration of HNTs was 10 mg/m L.The experimental results show that terahertz metamaterial sensor modified by HNTs can improve the detection sensitivity.（3）The specific recognition ability of terahertz metamaterial sensor to SCCA was studied when the surface was modified with SCCA antibodies.The experiment was divided into two groups:one was that the sensor only modified SCCA antibody;The other group modified both HNTs and SCCA antibodies.Two groups of sensors were used to test five different tumor markers.The results showed that the frequency shift of SCCA detection was more significant than other tumor markers regardless of whether the sensors modified HNTs.This demonstrates that transducers modified with SCCA antibodies can achieve specific detection.In addition,the frequency shift of the five tumor markers detected by the modified HNTs sensor was greater than that of the unmodified HNTs sensor,demonstrating the enhancement effect of HNTs.The terahertz metamaterial sensor designed in this paper and the method proposed to modify the sensor can be used to detect SCCA with high sensitivity and specificity,which has an important reference value for the early diagnosis of lung cancer.