Long-Life and pH-Stable SnO₂-Coated Au Nanoparticles for SHINERS

Abstract

Shell-isolated nanoparticles (SHINs) with a 37 nm gold core and an 11 nm tin dioxide (SnO 2 ) coating exhibited long-life Raman enhancement for 3 months and a wide pH stability of pH 2–13 in comparison with conventional SiO 2 -coated SHINs. Herein, Au–SnO 2 is demonstrated as a more durable SHIN for use in the technique Shell-Isolated Nanoparticles for Enhanced Raman Spectroscopy (SHINERS).

Multi-mode enhanced Raman scattering spectroscopy using aggregation-free hybrid metal/metal-oxide nanoparticles with intrinsic oxygen vacancies

“…2(b)) and the mass of chemically-enhancing SnO 2 which are all important considerations in such systems. 45 The sample Au NT–SnO 2 -2 was therefore selected for all subsequent measurements, unless otherwise stated.…”

“…In particular, a significant decrease in signal intensity was observed for the sample with thick SnO 2 coating (Au NT–SnO 2 -3), highlighting the importance of accessible surface on the Au NTs via the voids of the SnO 2 coating, and metal–analyte distance especially for analytes with low binding affinity to metal surfaces, such as DNT. 45 Meanwhile with this relatively low intensity UV source, it took approximately 1.5 hours of UV illumination for a maximum PIERS intensity to be reached (Fig. S22, ESI†).…”