Pinhole Effect on the Melting Behavior of Ag@Al(2)O(3) SERS Substrates

High-temperature surface-enhanced Raman scattering (SERS) sensing is significant for practical detections, and pinhole-containing (PC) metal@oxide structures possessing both enhanced thermal stability and superior SERS sensitivity are served as promising SERS sensors at extreme sensing conditions. Through tuning the Al(2)O(3) precursors’ exposure time during atomic layer deposition (ALD), Al(2)O(3) shells with different amount of pinholes were covered over Ag nanorods (Ag NRs). By virtue of these unique PC Ag@Al(2)O(3) nanostructures, herein we provide an excellent platform to investigate the relationship between the pinhole rate of Al(2)O(3) shells and the melting behavior, high-temperature SERS performances of these core-shell nanostructures. Pinhole effect on the melting procedures of PC Ag@Al(2)O(3) substrates was characterized in situ via their reflectivity variations during heating, and the specific melting point was quantitatively estimated. It is found that the melting point of PC Ag@Al(2)O(3) raised along with the decrement of pinhole rate, and substrates with less pinholes exhibited better thermal stability but sacrificed SERS efficiency. This work achieved highly reliable and precise control of the pinholes over Al(2)O(3) shells, offering sensitive SERS substrates with intensified thermal stability and superior SERS performances at extreme sensing conditions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s11671-016-1390-0) contains supplementary material, which is available to authorized users.