Parallel-scan based microarray imager capable of simultaneous surface plasmon resonance and hyperspectral fluorescence imaging

Abstract

With the development of the microarray technology, demands for array detection techniques become higher and higher. For many microarrays, several biomolecular interactions occur simultaneously and the interplay of various factors that affect these interactions remains poorly understood. Detecting such interactions with a single technique can often be a difficult and complicated process. In this work we propose a combined technique which enables simultaneous angle-interrogation surface plasmon resonance (SPR) sensing and hyperspectral fluorescence imaging. This tandem technique offers two-dimensional imaging of the whole array plane. The refractive index information obtained from SPR sensing and the physicochemical properties obtained from fluorescence imaging provide a comprehensive analysis of biological events on the array-chip. In addition, SPR and fluorescence detection techniques confirm each other in experimental results to exclude false-positive or false-negative cases. In terms of SPR sensing performance, the refractive index resolution is 3.86 × 10 −6 refractive index units (RIU), and the detection limit is 10 4 cfu/ml of Escherichia coli bacteria. The resolving power and detection sensitivity of fluorescence imaging are approximately 20 μm and 0.61 fluors/μm 2, respectively. Finally, two model experiments, detecting the DNA hybridization and biotin–avidin interactions respectively, demonstrate the biomedical application of this system.