A novel droplet-based surface-enhanced Raman scattering (SERS) sensor for high-throughput real-time SERS monitoring is presented. The developed sensors are based on a droplet-guiding-track-engraved superhydrophobic substrate covered with hierarchical SERS-active Ag dendrites. The droplet-guiding track with a droplet stopper is designed to manipulate the movement of a droplet on the superhydrophobic substrate. The superhydrophobic Ag dendritic substrates are fabricated through a galvanic displacement reaction and subsequent self-assembled monolayer coating. The optimal galvanic reaction time to fabricate a SERS-active Ag dendritic substrate for effective SERS detection is determined, with the optimized substrate exhibiting an enhancement factor of 6.3 × 105. The height of the droplet stopper is optimized to control droplet motion, including moving and stopping. Based on the manipulation of individual droplets, the optimized droplet-based real-time SERS sensor shows high resistance to surface contaminants, and droplets containing rhodamine 6G, Nile blue A, and malachite green are successively controlled and detected without spectral interference. This noble droplet-based SERS sensor reduces sample preparation time to a few seconds and increased detection rate to 0.5 µL s−1 through the simple operation mechanism of the sensor. Accordingly, our sensor enables high-throughput real-time molecular detection of various target analytes for real-time chemical and biological monitoring.
Bibliographical noteFunding Information:
This work was supported by the Priority Research Centers Program (2012-0006689) through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (MEST) and Mid-Career Researcher Program through NRF grant funded by the MEST (2014R1A2A2A09053061), and the R&D program of MOTIE/KEIT [10064081, Development of fiber-based flexible multimodal pressure sensor and algorithm for gesture/posture-recognizable wearable devices]. This work was partially supported by the Yonsei University Future-leading Research Initiative and Implantable artificial electronic skin for an ubiquitous healthcare system of 2016-12-0050.
All Science Journal Classification (ASJC) codes
- Materials Science(all)