Abstract

As a typical deoxyribonucleic acid (DNA) base with diverse amino/imino groups, guanine has remarkable Raman activity; however, its Raman modes are largely forbidden in solid Raman measurements, which hinders full understanding of the chemistry of such DNA bases. Here a study on surface-enhanced Raman scattering (SERS) of guanine is reported by employing colloidal silver nanoparticles modified on the silver electrode as substrate. High-quality SERS spectra with potential dependence were obtained, shedding light on the varying adsorption behavior of guanine on the nano-surface. High-quality SERS spectra have also been obtained for picolinic acid molecules. The good stability and homogeneous size distribution of silver nanoparticle coatings provide a highly SERS-active substrate for detecting DNA-bases and probing their local interactions.

摘要

作为具有不同氨基/亚氨基的典型脱氧核糖核酸 (DNA) 碱基，鸟嘌呤具有显着的拉曼活性；然而，它的拉曼模式在固体拉曼测量中基本上是被禁止的，这阻碍了对此类 DNA 碱基化学的充分理解。本文报道了一项关于鸟嘌呤表面增强拉曼散射 (SERS) 的研究，该研究采用在银电极上修饰的胶体银纳米粒子作为底物。获得了具有电位依赖性的高质量 SERS 光谱，揭示了鸟嘌呤在纳米表面上的不同吸附行为。还获得了吡啶甲酸分子的高质量 SERS 光谱。银纳米粒子涂层的良好稳定性和均匀的尺寸分布为检测 DNA 碱基和探测它们的局部相互作用提供了高度 SERS 活性的基质。