Immobilization of zeolitic imidazolate framework‐90 onto modified stainless steel wire via covalent bonding for solid‐phase microextraction of biomarkers in exhalation of lung cancer patients

Abstract

AbstractThe improvement of the strong force between the coating and the substrate is important to make the coating for solid‐phase microextraction with good stability, durability, and reproducibility during thermal and solvent desorption. In this paper, zeolitic imidazolate frameworks‐90 coating was immobilized on the stainless‐steel fiber via the chemical‐bonded method with the help of polydopamine. The fiber was used for the solid‐phase microextraction of lung cancer biomarkers prior to gas chromatography‐mass spectrometry analysis. Several extraction and desorption conditions were optimized. Under the optimized conditions, the established method exhibited high enrichment factors (434–7560), low limits of detection (2.6–4.2 ng/L), wide linear ranges (0.02–30 μg/L), good repeatability (3.46%–9.37% for intra‐day, 4.11%–9.18% for inter‐day, n = 6) and reproducibility (5.37%–7.02%, n = 3). Moreover, the coated fiber is thermally stable and can be reused at least 100 cycles of extraction/desorption/conditioning without significant loss of extraction efficiency and precision. Eventually, the self‐made coated fiber combined with gas chromatography‐mass spectrometry was successfully applied to the extraction and detection of five biomarkers of lung cancer from real breath samples with a satisfactory recovery (96.6%–117.6%).