Sensing Method Research Based On Porphyrins For Characteristic Breath Of Lung Cancer

According to the situation about low survival rate of lung cancer patient after final diagnosis, this work proposed porphyrin-sensing method to detect lung cancer based on Breath Diagnosis. Through a research on trace volatile organic compounds of the breath gas from lung cancer patient, early noninvasive diagnosis and monitoring pathogenetic condition could be realized for patients.Sensing methods with VOCs about domestic and overseas investigation were introduced. Analyzing their advantage and disadvantage, new detecting method based on optical spectrum with porphyrin was proposed. First, several kinds of porphyrins and derivates were prepared. UV-Vis, Infrared absorption spectroscopy, and HNMR were used to characterize their structure and property. The synthetical compounds were confirmed for our target compounds.Secondly, sensitivity test on optical spectrum between porphyrins and VOCs of breath gas from lung cancer patients was studied. UV-Vis was used to scan successively with their mixed solution before and after reaction. Then, UV-Vis spectra change of single porphyrin exposed to single analytes, detection limit and featured interactional respond were determined, and some porphyrins were discovered that their limit of detection with target analytes was low to 1×10-8. The relationship between the structure of porphyrin and sensitivity, and their mechanism of action was elucidated simply according to the spectra change of P1 with nine kinds of target analytes.Cross-selecting of multitude sensitive materials can avoid the disadvantage of single material performance, and improve the specificity and selectivity for target analytes. Handiwork spotting was applied to prepared 6×6 porphyrin arrays with porphyrins and indicators. Owing to the colour change of porphyrin arrays, when porphyrins reacted with gas molecule, porphyrin array images before and after exposure to different concentrations of analytes were collected with porphyrin sensing micro-system designed by our lab, and gained the response characteristic spectrum of every analyte either. Principle Component and Hierarchical Cluster Analysis for featured responding RGB data of porphyrin array was conducted. The results showed that the detection had good repeatability and the nine analytes can be distinguished completely with good clustering in condition of low resemblance dimension.As porphyrins have such advantages of optical performance, the mechanism of action for porphyrins with gas molecule was identified for further study. When the stability and sensitivity keep well, porphyrin sensor with excellent performance could be developed for early diagnosis and ambulatory monitoring of lung cancer.