The majority of analytical chemistry methods requires presence of target molecules directly at a sensing surface. Diffusion of analyte from the bulk towards the sensing layer is random and might be extremely lengthy, especially in case of low concentration of molecules to be detected. Thus, even the most sensitive transducer and the most selective sensing layer are limited by the efficiency of deposition of molecules on sensing surfaces. However, rapid development of new sensing technologies is rarely accompanied by new protocols for analyte deposition. To bridge this gap, we propose a method for fast and efficient deposition of variety of molecules (e.g. proteins, dyes, drugs, biomarkers, amino acids) based on application of the alternating electric field. We show the dependence between frequency of the applied electric field, the intensity of the surface enhanced Raman spectroscopy (SERS) signal and the mobility of the studied analyte. Such correlation allows for a priori selection of parameters for any desired compound without additional optimization. Thanks to the application of the electric field, we improve SERS technique by decrease of time of deposition from 20 h to 5 min, and, at the same time, reduction of the required sample volume from 2 ml to 50 μl. Our method might be paired with number of analytical methods, as it allows for deposition of molecules on any conductive surface, or a conductive surface covered with dielectric layer.

大多数分析化学方法要求目标分子直接存在于传感表面。分析物从本体向传感层的扩散是随机的，并且可能非常漫长，特别是在要检测的分子浓度较低的情况下。因此，即使是最灵敏的换能器和最具选择性的感测层也受到分子在感测表面上的沉积效率的限制。然而，新的传感技术的快速发展很少伴随着用于分析物沉积的新协议。为了弥合这一差距，我们提出了一种基于交变电场的方法，可以快速有效地沉积各种分子（例如蛋白质，染料，药物，生物标记物，氨基酸）的方法。我们展示了所施加电场的频率之间的依赖性，表面增强拉曼光谱（SERS）信号的强度以及所研究分析物的迁移率。这种相关性允许任何所需化合物的参数先验选择，无需额外优化。由于施加了电场，我们通过将沉积时间从20 h减少到5 min，同时将所需的样品量从2 ml减少到50μl，改进了SERS技术。我们的方法可能与许多分析方法结合使用，因为它允许分子沉积在任何导电表面或覆盖有介电层的导电表面上。