Wang et al. 2025 — Concave nanogap SERS sensor for Hg, Pb, and Cd detection
This paper reports the fabrication of a concave-nanogap nanostructure functionalized with aptamers for surface-enhanced Raman scattering (SERS) detection and in situ imaging of mercury (Hg2+), lead (Pb2+), and cadmium (Cd2+) ions. The sensor exploits the intense electromagnetic field enhancement within the nanogap “hot spot” to achieve sub-nanomolar detection limits. Applications are demonstrated in spiked water samples, herbal plant extracts, and zebrafish as a biological matrix, but no occurrence measurements of actual heavy metal concentrations in food matrices are reported.
Key numbers
- LOD for Hg2+: 0.1 nM (reported as the primary benchmark analyte)
- Simultaneous multi-metal detection: Hg2+, Pb2+, and Cd2+
- Matrix validation: ultrapure water, spiked herbal plant extracts, zebrafish tissue (in situ imaging)
- Published in Analytical Chemistry 2025, 97, 23516–23525
Methods (brief)
Concave-nanogap gold nanostructures were synthesized and functionalized with metal-specific aptamers. SERS spectra were recorded under 785 nm laser excitation. The sensor was validated against spiked matrices. No ICP-MS or AAS reference measurements of food commodity occurrence are provided.
Implications
Certification: Not applicable — no occurrence data for food matrices. Courses: Useful as an example of next-generation SERS-based rapid screening tools for heavy metals in food safety contexts. App: No contamination profile data extractable from this source.