Publication Details

Yan, S., Chu, F., Zhang, H., Yuan, Y., Huang, Y., Liu, A., Wang, S., Li, W., Li, S. & Wen, W. (2019). Rapid, one-step preparation of SERS substrate in microfluidic channel for detection of molecules and heavy metal ions. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 220 117113-1-117113-8.


On-chip fabrication of surface-enhanced Raman spectroscopy (SERS)-active materials enables continuous, real-time sensing of targets in the microfluidic chip. However, the current techniques require the time-consuming, complicated process and costly, bulky facilities. In this work, we present a novel method for synthesis of Ag nanostructures in a microfluidic channel via one-step electroless galvanic replacement reaction. The whole reaction could be achieved <10 >mins, while the traditional methods take hours. The microfluidic channel has a Cu base, which can reduce Ag ions to Ag nanoparticles in the presence of AgNO3 solution. The new technique enables the label-free sensing of chemical molecules (i.e., methylene blue)and biomolecules (i.e., urea). Two proof-of-concept experiments are performed to verify the utilization of the prepared SERS substrate. First, the microfluidics-assisted SERS sensor is used to detect Hg ions in aqueous solution with high sensitivity and good selectivity. Second, the fabricated SERS-active material can couple with a concentration gradient generator for continuous SERS detection. This simple technique can be used in any laboratory without any bulky equipment and can realize numerous lab-on-a-chip applications with the integration of other microfluidic networks.

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