An Investigation of the Laser Refrigeration Assisted Surface-Enhanced Raman Sepectrocopy by Gold Nanorods with Specified Plamonic Wavelength

Abstract

Surface-Enhanced Raman spectroscopy (SERS) technique largely broaden the application of Raman spectroscopy, which is a powerful analytical technique that provides valuable insights into the molecular composition and structure of a wide range of materials. Here, we synthesize a gold nanorods with specific plasmonic resonance at both 532nm and 1020nm to obtain excellent Raman enhance ability which can be further improved by combining the ytterbium doped Sodium Yttrium Fluoride (NaYF:Yb3+) to possess laser refrigeration capability that may allow high laser power as well as better resolution under same experimental conditions.This article used scanning electron microscopy and transmission electron microscopy to characterize the synthesized gold nanorods (AuNRs). After confirming the aspect ratio is about 6.6 ± 1.6, the UV-Vis spectrometer is used to collect the plasmonic resonance peak of the AuNRs which is at 519nm and 1017nm respectively. Furthermore, two target molecules includes rhodamine 6G (R6G) and Bovine Serum Albumin (BSA) were used for the SERS ability investigation. Moreover, this article innovatively applied anti-stokes/stokes Raman ratio as a nano thermometer to acquire the in-situ temperature information of the system, which preliminary confirm the possibility of cooling the system and protecting the sample while the Raman spectrum collection.