Real-time SPR sensor array based on DMD-enabled angular interrogation with a single point photodetector (Conference Presentation)

In this work, we present a digital micro-mirror device (DMD)-enabled real-time biosensing array based on angular interrogation surface plasmon resonance (SPR) with a single point photodetector. It has been studied that the performance of SPR sensors are predominantly limited by photon statistics, which can be achieved by increasing the photon capture efficiency and dynamic range of the detector. Such attributes uniquely put the single point photodetector as a potential light detecting element in high performance SPR sensors. In our DMD-based-SPR system, angular scanning is achieved by the DMD which facilitates SPR measurements with a single point photodetector, leading to a high-performance system with user-selectable interrogation range, enhanced S/N ratio and fast data throughput. Experimental results demonstrate a system resolution of 3.54×10−6 in terms of refractive index unit (RIU). Using a 4-channel array setup, we have performed real-time monitoring of bovine serum albumin (BSA)/anti-BSA binding interactions at various concentration levels. The limit of detection (LOD) is 27 ng/mL. DMD-based SPR interrogation opens up a new design route for practical solid-state SPR biosensors.