Detection of lung cancer aldehydes biomarker by Al2O3/Ag/ZIF-8 SERS quasi cavity with co-confinement effect

The utilization of surface-enhanced Raman scattering (SERS) technology for monitoring aldehydes in human exhaled gas represents a burgeoning method for early screening of lung cancer; however, it currently faces several challenges: firstly, the limited capacity of SERS substrates to capture aldehyde molecules, and secondly, the low degree of co-localization between aldehyde molecules and hotspot spatial distribution. To address these issues, this study proposes an Al₂O₃/Ag/ZIF-8 SERS quasi-cavity structure, which enables the dual regulation of intramolecular hotspots, the capture of gaseous analytes, and the micro-localized co-localization of "hotspots-analytes." Leveraging this structure, we achieved sensitive detection of ethyl benzaldehyde molecules over a concentration range of 0.2 ppb-20 ppm, and preliminarily explored its specific recognition of aldehyde biomarkers in human exhaled gas. This research provides a versatile SERS detection strategy for gaseous molecules, offering significant reference value for the accurate detection of various cancer-associated gaseous biomarkers in human exhalations.