Targeted Suppression of Peptide Degradation in Ag‐Based Surface‐Enhanced Raman Spectra by Depletion of Hot Carriers. Issue 52 (7th November 2022)

• Record Type: Journal Article
• Authors: Yao, Xiaobin; Höppener, Christiane; Schneidewind, Henrik; Hoeppener, Stephanie; Tang, Zian; Buchholz, Axel; König, Annika; Mogavero, Selene; Diegel, Marco; Dellith, Jan; Turchanin, Andrey; Plass, Winfried; Hube, Bernhard; Deckert, Volker
• Is Part Of: Small. Volume 18:Issue 52(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-07
• Subjects: Ag‐surface‐enhanced Raman spectroscopy (SERS) -- hot carriers -- iodides -- Kelvin probe force microscopy -- peptides -- sample degradation; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202205080
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Sample degradation, in particular of biomolecules, frequently occurs in surface‐enhanced Raman spectroscopy (SERS) utilizing supported silver SERS substrates. Currently, thermal and/or photocatalytic effects are considered to cause sample degradation. This paper establishes the efficient inhibition of sample degradation using iodide which is demonstrated by a systematic SERS study of a small peptide in aqueous solution. Remarkably, a distinct charge separation‐induced surface potential difference is observed for SERS substrates under laser irradiation using Kelvin probe force microscopy. This directly unveils the photocatalytic effect of Ag‐SERS substrates. Based on the presented results, it is proposed that plasmonic photocatalysis dominates sample degradation in SERS experiments and the suppression of typical SERS sample degradation by iodide is discussed by means of the energy levels of the substrate under mild irradiation conditions. This approach paves the way toward more reliable and reproducible SERS studies of biomolecules under physiological conditions. Abstract : Biosample degradation significantly limits the application of surface enhanced Raman spectroscopy (SERS) and often causes mis‐assignments of spectra. Using iodide solutions not only suppresses sample degradation in SERS and provides signal similar to standard Raman spectra, it also provides insight into the photocatalytic mechanisms behind the degradation process.