Drop-casting is frequently used to deliver a sample for surface-enhanced Raman spectroscopy (SERS) and can result in inhomogeneous sample distribution during solvent evaporation. While soaking can provide better analyte homogeneity, it may require more sample than is available. Failure to optically sample analyte-rich substrate locations can compromise measurement outcomes. We developed and tested 3D printed SERS substrate holders that provided spatial registry of the dried sample droplet center for subsequent optical measurements. We found that deliberate and controlled spatial offsets (0–900 µm) between the analyte drop center and the laser excitation prevented signal intensity drops of as much as ∼3× and improved reproducibility. Thus, the use of offset-controlled 3D printed holders provided a quick and inexpensive way to improve the reliability of SERS measurements when using the convenient and popular choice of sample drop-casting.

中文翻译：

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使用3D打印对准支架，可提高平面基板在表面增强拉曼光谱中的可重复性

滴铸法通常用于输送样品进行表面增强拉曼光谱（SERS），并可能导致溶剂蒸发过程中样品分布不均匀。虽然浸泡可以提供更好的分析物均匀性，但可能需要比可用样品更多的样品。无法对富含分析物的基质位置进行光学采样会损害测量结果。我们开发并测试了3D打印的SERS基板支架，该支架为干燥的样品液滴中心提供了空间配准，以用于后续的光学测量。我们发现故意的和受控的空间偏移（0–900 µm）在分析物滴中心与激光激发之间可防止信号强度下降约3倍，并提高了重现性。因此，当使用方便且普遍的样品滴铸选择时，使用偏移控制的3D打印支架可提供一种快速而廉价的方法来提高SERS测量的可靠性。