Analysis of Carbonyl Compounds in Exhaled Breath for Identificationf of LUNG Cancer Biomarkers

Some carbonyl compounds have been identified as biomarkers of lung cancer. We report a fabricated reactive chip with thousands of micropillars in a microfluidic channel that have been engineered to selectively preconcentrate trace volatile ketones and aldehydes in exhaled breath. These carbonyl compounds are directly related to lung cancer induced metabolic dysfunction and oxidative stress. The chips are fabricated using deep reactive ion etching (DRIE) of silicon. The micropillar surface is functionalized with a reactive quaternary ammonium aminooxy salt  for trapping trace carbonyl compounds by means of an oximation reaction. The chips are used for directly preconcentrating carbonyl compounds in breath. The concentrated ketone- and aldehyde-aminooxy adducts are analyzed by ultra-high performance liquid-chromatograh-mass spectrometry (MS). Some carbonyl compounds including hydroxyl-acetaldehyde, 2-butanone, 4-hydroxy-hexenal are identified as lung cancer biomarkers by statistical data analysis of healthy control group breath samples and lung cancer patient breath samples.