Early Diagnosis And Sensing Method Of Lung Cancer Based On Porphyrins

Breath Diagnosis is a noninvasive diagnostic technique. Through the identification of featured components and the determination of their concentrations, diagnosis and screening of patients can be realized, so it is a prospective diagnostic and tutelary method.According to some domestic and abroad research reports which focused on the relationship between certain volatile organic compound(sVOCs) in breath and the lung cancer, this thesis mainly took the lung cancer diagnostic model established by Dr. Phillips as a reference. In his research, 22 diagnostic VOCs were screened out for lung cancer diagnosis, and based on such a start we selected 5 diagnostic VOCs as the experimental target analytes: benzene, n-heptanal, styrene, p-xylene andα-methylstyrene. Porphyrins and metalloporphyrins were used as sensitive materials for the detection of the 5 target analytes, and sensing technique of their interactional responds were studied as a main part.Aimed at the five target analytes, the following work was completed:Firstly, nine kinds of porphyrins and metalloporphyrins were prepared. Liquid sensitivity screening of these pophyrins to five target analytes was carried out by UV-Vis spectra sensitive experiments. Through comparing the UV-Vis spectra change of single porphyrin exposed to single analytes, detection limit and featured interactional respond were determined and three well sensitive porphyrins were screened: P1, P2 and P3; SEMICA-P software was used for Principle Component Analysis of spectra data resulted from single porphyrin reacted with five analytes, and the result showed that, although the detection limit of single porphyrin was rather low, the specificity was not ideal.Secondly, porphyrins and indicators spotting were conducted on hydrophobic PVDF films by capillary. In order to realize the separate reaction between porphyrin-dye array and single analyte, 4×3 porphyrin-dye arrays were prepared, and gas generator and reacting system equipment were constructed. Porphyrin-dye array images before and after exposure to different concentrations of analytes were collected for MATLAB analyzing, and responding characteristic were obtained. The results showed that, respond time of porphyrin array to single analyte was several minutes and the detection limit can be lower than ppm. For different analyte, the responding characteristic was also different, so qualitative analysis was realized. Humidity change had little impact on the porphyrin-dye array, but indicators were influenced by humidity to some extent. Principle Component Analysis for featured responding RGB data of porphyrin-dye array was conducted. The results showed that the detection had good repeatability and the five analytes can be distinguished completely with good clustering.As the optical sensor has such advantages of stable performance, rapid respond time, low detection limit, high sensitivity and little humidity influence of the optical sensor, we can use the optical property of porphyrin-dye array to detect the volatile organic compounds in breath so as to realize the lung cancer patient screening and ground for the monitoring of patient with lung cancer.