Abstract
Formaldehyde is a strong-smelling, colorless, excitant gas that is carcinogenic to humans. It is frequently used in the interior of decorative materials such as wood paneling and carpets. Several epidemiological studies have shown that the increasing incidence of nasal and lung cancer is due to exposure to environmental formaldehyde. Thus, the rapid detection of formaldehyde with high sensitivity is vitally important for environmental monitoring and clinical diagnosis. Surface-enhanced Raman scattering (SERS) is an analytical technique that can provide fingerprint information on target materials with a sensitivity even down to the single-molecule level. However, formaldehyde molecules have a low cross section for Raman scattering and extremely weak analyte–metal interactions, and are thus scarcely detectable with conventional SERS technology. In this paper, a porous zeolitic imidazolate framework-8 (ZIF-8) shell layer was grown in situ on gold nanostars (AuNSs) for capturing and altering the route taken by formaldehyde molecules. Compared with current SERS detection methods, these as-synthesized core–shell AuNS@ZIF-8 nanocomposites with special apertures can cause formaldehyde molecules to pass through the ZIF-8 channels to the metal surface. With the help of ZIF-8 shell layers, the SERS-active AuNS@ZIF-8 substrates display extremely high sensitivity to formaldehyde molecules, with the lowest detection level almost at parts per billion (ppb). This study may therefore provide the basis for a reliable SERS strategy for detecting small molecules, especially gas samples.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.