A highly sensitive microfluidics system for multiplexed surface-enhanced Raman scattering (SERS) detection based on Ag nanodot arrays

We report a method for fabricating a highly sensitive, microfluidic surface-enhanced Raman scattering (SERS) chip with highly ordered Ag nanodot arrays as the enhancement substrate for the detection of multiplexed low-concentration analytes. The microfluidic SERS chip features a highly-ordered Ag nanodot array on quartz slides fabricated by depositing Ag with an ultrathin anodic aluminium oxide (AAO) film as template and a channel-patterned polydimethylsiloxane (PDMS) cover on top, allowing a tremendous enhancement of electromagnetic field in the proximity of the chip surface because of the localized surface plasmon resonance (LSPR) of the Ag nanodots. Via the utilization of a self-built SERS microspectrometer with an inverted configuration, the multiplexed SERS signals of low concentration adenine and thiram can be readily detected with a detection limit down to 5.0 x 10(-7) M. This detection system that we developed is flexible and has potential for real commercialization.