In the present investigation, the conformational analysis was carried out to predict the most stable molecular structure of the 1-Methylpyrrole-2-carbonyl chloride (MPCC) molecule. Further, the molecular structure of MPCC, MPCC-Ag₃, and MPCC-Au₄ molecular systems were optimized. To obtain the strong SERS enhancement, SERS substrates such as silver and gold films were fabricated. SEM images of silver and gold films confirm that the silver and gold nanoparticles in the corresponding films are spherical with particle sizes of 42 and 13 nm, respectively. Based on the corresponding XRD patterns, the crystallite size of silver and gold films was predicted to be 36.89 and 10.99 nm, respectively. UV–visible spectral analysis shows a widespread red-shift, which confirms that the MPCC molecule adsorbed on silver and gold film surfaces. Frontier molecular orbitals analysis shows that the charge transfer occurs between the metal clusters and MPCC molecule in the MPCC-Ag₃ and MPCC-Au₄ molecular systems. The charge transfer interaction in the investigated molecular systems was further verified using the molecular electrostatic potential surface and Fukui functions analysis. The nRs and SERS investigations provide evidence that the MPCC molecule is chemisorbed on gold film with higher binding affinity than the silver film with tilted orientation through the lone pair electrons of oxygen atom in the CO functional group, pyrrole ring π electrons and lone pair electrons of the chlorine atom. Experimentally observed results were highly correlated with theoretical results. As a result, the present study paves the way for the development of pyrrole-associated biosensors by facilitating the design of strong SERS active substrates.

在本研究中，进行了构象分析以预测 1-甲基吡咯-2-碳酰氯 (MPCC) 分子最稳定的分子结构。此外，MPCC、MPCC-Ag ₃和 MPCC-Au ₄的分子结构分子系统得到优化。为了获得强大的 SERS 增强，制造了 SERS 基板，如银和金膜。银和金薄膜的 SEM 图像证实相应薄膜中的银和金纳米粒子是球形的，粒径分别为 42 和 13 nm。根据相应的 XRD 谱，预测银膜和金膜的微晶尺寸分别为 36.89 和 10.99 nm。紫外-可见光谱分析显示广泛的红移，这证实 MPCC 分子吸附在银和金薄膜表面。前沿分子轨道分析表明，在 MPCC-Ag ₃和 MPCC-Au ₄中，电荷转移发生在金属簇和 MPCC 分子之间分子系统。使用分子静电势面和福井函数分析进一步验证了所研究分子系统中的电荷转移相互作用。nRs和SERS研究提供的证据表明，MPCC分子通过CO官能团中氧原子的孤对电子、吡咯环π电子和孤对电子以倾斜取向比银膜化学吸附在金膜上具有更高的结合亲和力氯原子。实验观察结果与理论结果高度相关。因此，本研究通过促进强 SERS 活性底物的设计，为吡咯相关生物传感器的开发铺平了道路。