分析物分子在纳米光电极上的吸附(例如，组合的纳米天线和纳米电极装置）显着影响表面增强拉曼散射（SERS）测量中的信号特性。了解不同分子如何吸附在电极上以及它们对电势的调制有助于更好地解释SERS测量。这项工作研究了原型分析物分子的吸附，罗丹明6G和胆碱，在带有负极的金电极上，中性,和使用分子动力学模拟的正表面电荷。我们表明，在此处考虑的所有表面电荷密度下，两种分子都可以轻松吸附在金表面上。然而，对于不同的表面电荷密度，吸附分子的构型可以不同，和吸附也可以改变分子的构象。罗丹明6G分子比胆碱分子吸附更强，在0.25MNaCl溶液中，两种分子的吸附都受电极电荷的影响。这些观察的机制被阐明，并讨论了它们对SERS测量的影响。
The adsorption of analyte molecules on nano-optoelectrodes (e.g., a combined nanoantenna and nanoelectrode device) significantly affects the signal characteristics in Surface-Enhanced Raman Scattering (SERS) measurements. Understanding how different molecules adsorb on electrodes and their modulation of electrical potential help better interpret SERS measurements. This work investigates the adsorption of prototypical analyte molecules, Rhodamine 6G and choline, on gold electrodes with negative, neutral, and positive surface charges using molecular dynamics simulations. We show that both molecules can readily adsorb on gold surfaces at all surface charge densities considered here. Nevertheless, the configurations of adsorbed molecules can differ for different surface charge densities, and adsorption can also change a molecule\'s conformation. Rhodamine 6G molecules adsorb more strongly than choline molecules, and the adsorption of both molecules is affected by electrode charge in 0.25 M NaCl solutions. The mechanisms of these observations are elucidated, and their implications for SERS measurements are discussed.
