Hybrid superhydrophilic-superhydrophobic micro/nanostructures fabricated by femtosecond laser-induced forward transfer for sub-femtomolar Raman detection
Hybrid superhydrophilic-superhydrophobic micro/nanostructures fabricated by femtosecond laser-induced forward transfer for sub-femtomolar Raman detection
复制标题
飞秒激光诱导正向传输制备混合超亲水-超疏水微/纳米结构用于亚飞摩尔拉曼检测
DOI：
10.1038/s41378-019-0090-1
复制
发表时间：
2019-09-23
影响因子：
7.9
通讯作者：
Cui, Tianhong
中科院分区：
文献类型：
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作者：
Ma, Xiaodan;Jiang, Lan;Cui, Tianhong
拉曼光谱在生化分析中起着至关重要的作用。近年来，超疏水表面增强拉曼散射（Sers）基底通过将目标分子集中到小区域内来提高检测限。然而，由于湿转变现象，阻止了液滴接触面积的进一步减小，并且限制了检测极限。本文提出了一种利用飞秒激光诱导前向转移制备超疏水-超疏水Sers（HS-SERS）基底的简单方法，通过引入超亲水图案促进目标分子在其上聚集，从而实现超痕量检测。此外，加热HS-SERS基底以促进更小的集中区域。通过溶液与基底接触形成的水蒸气膜克服了液滴塌陷，目标分子完全集中到超亲水区域，而不会在蒸发过程中损失。最后，成功地减少了集中区域，提高了检测限。HS-SERS基底实现了0.013 mm（2）的最终接触面积，比未加热的情况减少了12.1倍。接触面积的减少导致罗丹明6 G溶液的检测限浓度低至10（-16）M。此外，HS-SERS基底通过超亲水图案精确地控制了集中区域的大小，这可以归因于液滴浓度结果的良好重复性。此外，该制备方法灵活，在流体混合、流体输送、生化传感器等方面具有潜力。
Raman spectroscopy plays a crucial role in biochemical analysis. Recently, superhydrophobic surface-enhanced Raman scattering (SERS) substrates have enhanced detection limits by concentrating target molecules into small areas. However, due to the wet transition phenomenon, further reduction of the droplet contact area is prevented, and the detection limit is restricted. This paper proposes a simple method involving femtosecond laser-induced forward transfer for preparing a hybrid superhydrophilic-superhydrophobic SERS (HS-SERS) substrate by introducing a superhydrophilic pattern to promote the target molecules to concentrate on it for ultratrace detection. Furthermore, the HS-SERS substrate is heated to promote a smaller concentrated area. The water vapor film formed by the contact of the solution with the substrate overcomes droplet collapse, and the target molecules are completely concentrated into the superhydrophilic region without loss during evaporation. Finally, the concentrated region is successfully reduced, and the detection limit is enhanced. The HS-SERS substrate achieved a final contact area of 0.013 mm(2), a 12.1-fold decrease from the unheated case. The reduction of the contact area led to a detection limit concentration as low as 10(-16) M for a Rhodamine 6G solution. In addition, the HS-SERS substrate accurately controlled the size of the concentrated areas through the superhydrophilic pattern, which can be attributed to the favorable repeatability of the droplet concentration results. In addition, the preparation method is flexible and has the potential for fluid mixing, fluid transport, and biochemical sensors, etc.