SERS and DFT studies of 2‐(trichloroacetyl)pyrrole chemisorbed on the surface of silver and gold coated thin films: In perspective of biosensor applications

Abstract

The adsorption and orientations of 2-(trichloroacetyl)pyrrole (TCAP) adsorbed on a fabricated silver-coated thin film (SCF), and gold-coated thin film (GCF) were investigated using surface-enhanced Raman scattering (SERS) studies and compared with the normal Raman scattering (nRs) spectrum of TCAP. The observed nRs and SERS spectra of TCAP were validated theoretically using DFT quantum chemical calculations. Initially, the molecular structure of TCAP, TCAP-Ag 3 , and TCAP-Au 4 molecular systems were optimized and analyzed. The fabricated SCF and GCF are characterized using FESEM analysis, which confirms that the silver and gold nanoparticles of the corresponding films are spherical in shape. The obtained significant red-shift in UVvisible spectra of TCAP added on SCF and GCF surfaces reveal that the TCAP strongly adsorbed on SCF and GCF surfaces. The frontier molecular orbitals analysis authenticates the charge-transfer interaction from Ag 3 and Au 4 metal clusters to the TCAP molecule, leading to the adsorption of TCAP molecule on Ag 3 and Au 4 metal clusters, which validates the UV-vis results. SERS spectral analysis confirms that the TCAP chemisorbed on SCF and GCF surfaces with tilted orientation and the corresponding results were validated theoretically. The calculated SERS enhancement factor values illustrate that the GCF surface exhibits a higher SERS signal enhancement than the SCF surface. Therefore, the present investigation will be useful for the development of active SERS substrates and pyrrole-related biosensors.

Can DFT Calculations Provide Useful Information for SERS Applications?

“…The DFT approach is increasingly used for SERS spectroscopy by several research groups, as demonstrated by the most recent studies [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ] in which close links between DFT calculations and SERS applications are shown. Among these studies, the following studies devoted to applications in sensors, especially for environmental protection, and to applications in biomedicine, are worthy of particular attention.…”

Green Synthesis of Pyrrole Derivatives Catalyzed by Molecular Sieves: DFT, ADMT, and Molecular Docking Investigations

“…[20] Furthermore, the investigation of the adsorption and orientations of 2-(trichloroacetyl)pyrrole (TCAP) on silver-coated and gold-coated thin films using surfaceenhanced Raman scattering (SERS) provides valuable insights for the development of active SERS substrates and pyrrolerelated biosensors, with potential applications in chemical analysis and biosensing. [21] In-silico methods have been successfully incorporated with drug discovery research since they can analyze complex biological and chemical systems. [22] A combination of computational and experimental methods is also frequently used to identify and develop new promising compounds.…”

“…In this regard, the pyrrole‐2,3‐dicarboxylate‐based compounds are explored in terms of the capability of using them as potential anti‐cancer agents against hepatic carcinoma, employing computational drug design techniques and experimental analyses; the synthesized compounds demonstrated significant anti‐hepatic carcinoma activity, indicating their potential as novel therapeutic candidates for treating liver cancer [20] . Furthermore, the investigation of the adsorption and orientations of 2‐(trichloroacetyl)pyrrole (TCAP) on silver‐coated and gold‐coated thin films using surface‐enhanced Raman scattering (SERS) provides valuable insights for the development of active SERS substrates and pyrrole‐related biosensors, with potential applications in chemical analysis and biosensing [21] …”