The sensitive detection of trace biomarkers in exhaled
breath for
lung cancer diagnosis represents a critical area of research in life
analytical chemistry, with profound implications for early disease
detection, therapeutic intervention, and prognosis monitoring. Despite
its potential, the analytical process faces significant challenges
due to the ultratrace levels of disease biomarkers present and the
complex, high-humidity composition of exhaled breath. This study introduces
a highly sensitive method for detecting aldehyde biomarkers in exhaled
breath by integrating the use of amino-functionalized microporous
organic networks (NH2-MON) as a solid-phase microextraction
(SPME) fiber coating with gas chromatography–triple quadrupole
mass spectrometry (GC-MS/MS) analysis. The method innovatively combines
sample collection and extraction, achieving a dual-step enrichment
process that significantly enhances both the enrichment efficiency
and reproducibility of biomarker detection while effectively mitigating
the interference caused by water vapor in exhaled breath. The NH2-MON, utilized as an SPME fiber coating, demonstrates exceptional
enrichment capacity for five key aldehyde biomarkers, facilitating
the development of a highly sensitive detection approach for these
biomarkers in exhaled breath. Compared to previously reported methods,
the proposed technique exhibits significantly lower limits of quantification,
ranging from 0.77 to 11.89 pg mL–1, and achieves
substantially higher enrichment factors, ranging from 9156- to 35723-fold.
The practicality and feasibility of the method were validated through
the analysis of exhaled breath samples from lung cancer patients,
underscoring its potential application in the early diagnosis and
monitoring of lung cancer.