RESUMO
Lung cancer (LC) is the leading cause of cancer mortality so, the analysis of exhaled human breath has great significance for early non-invasive diagnosis. Poor selectivity and strong humidity are two bottlenecks for the application of gas sensors to exhaled breath analysis. The development of novel extractive phases for the analysis of exhaled breath by chromatography is therefore a lucrative object. Polyhedral oligomeric silsesquioxanes (POSS) are among the 3D porous materials whose unique properties make them promising coatings for solid-phase microextraction (SPME). Selective enrichment of polar or nonpolar targets depends on the pore size and functional groups on the POSSs. Herein, we disclosed 3D network of POSS-naphthalene diimide (POSS-NDI) and perylene diimide (POSS-PDI) as extractive phases for analysis of lung cancer biomarkers with the capability of capturing different volatile organic compounds (VOCs). The synthesized diimides were fully characterized by FT-IR, multinuclear NMR, SEM, TEM, TGA, and BET analysis. After optimization of all the influential parameters on sorption/desorption, figures of merit for three aldehydes as biomarkers of LC were obtained. The exhaled breath of twelve participants including seven healthy candidates and five cases with LC were examined. The partial least squares-discriminant analysis (PLS-DA) was implemented which led to the proper classification of healthy and LC patients with R2 calibration and cross-validation of 0.9738 and o.7882, respectively.