Integrated opto-microfluidic interferometric chemical sensors on silicon chip with enhanced sensitivity

We present the experimental results of two integrated optomicrofluidic interferometer-based chemical sensors on silicon chips, designed for TE polarization at 1550 nm and TM polarization at 1310 nm, respectively. The sensors detect phase shifts in the optical signal resulting from interaction with a liquid sample flowing over an exposed waveguide section on one branch of an interferometer. The devices are compared in terms of sensitivity and resolution. The TE device is subsequently functionalized for the specific detection of prostate-specific antigen (PSA), within clinical relevant concentration range and an estimated limit of detection (LOD) of 0.006 ng/mL.