Rapid preparation of surface-enhanced Raman substrate in microfluidic channel for trace detection of amoxicillin

A high sensitive surface-enhanced Raman scattering (SERS) substrate based on the Ag dendrite in a T-type microfluidic device was constructed by a simple and rapid strategy. According to the simulated results by COMSOL Multiphysics, the microfluidic-SERS sensor was fabricated by simultaneously introducing into 40 mmol·L⁻¹ silver nitrate solution and 0.2 mol·L⁻¹ sodium nitrate solution for about 15 min with the flow velocity at 20 mL·min⁻¹ at room temperature, respectively. The analytical performance of this sensor was investigated with different concentrations of amoxicillin aqueous solution, and the detection limit was up to 1.0 ng·mL⁻¹. And the semi-quantitation was obtained from the relationship between the Raman intensity and the logarithm of the amoxicillin concentration. This method can be employed to fabricate high sensitive microfluidic-SERS sensors as well as realize many lab-on-a-chip applications with the integration of other microfluidic networks.