Abstract
A mid-infrared sensor for label-free on-chip chemical detection was developed using an engineered nanofluidic channel consisting of a Si-liquid-Si slot-structure. A sensitivity with 75 times improvement was achieved compared to conventional evanescent-wave sensing.
Mid-infrared spectroscopy is a detection technique commonly used for identifying biochemicals and tracing of toxic molecules, and is free of target labels and sensor surface functionalization. The use of mid-IR spectrum circumvents the need for labeling the sample, because the characteristic wavelength of absorption by many functional groups present in chemical or biological molecules falls within this region of the spectrum. Herein, we present a new chip-scale optofluidic device that utilizes mid-IR techniques for label-free and surface functionalization-free chemical sensing.