title: Real-time protein biosensor arrays based on surface plasmon resonance differential phase imaging.
abstract: This paper reports the application of differential phase surface plasmon resonance (SPR) imaging in two-dimensional (2D) protein biosensor arrays. Our phase imaging approach offers a distinct advantage over the conventional angular SPR technique in terms of utilization efficiency of optical sensor elements in the imaging device. In the angular approach, each biosensor site in the biosensor array requires a linear array of optical detector elements to locate the SPR angular dip. The maximum biosensor density that a two-dimensional imaging device can offer is a one-dimensional SPR biosensor array. On the other hand, the phase-sensitive SPR approach captures data in the time domain instead of the spatial domain. It is possible that each pixel in the captured interferogram represents one sensor site, thus offering high-density two-dimensional biosensor arrays. In addition, our differential phase approach improves detection resolution through removing common-mode disturbances. Experimental results demonstrate a system resolution of 8.8 x 10(-7)RIU (refractive index unit). Real-time monitoring of bovine serum albumin (BSA)/anti-BSA binding interactions at various concentration levels was achieved using a biosensor array. The detection limit was 0.77 microg/ml. The reported two-dimensional SPR biosensor array offers a real-time and non-labeling detection tool for high-throughput protein array analysis. It may find promising applications in protein therapeutics, drug screening and clinical diagnostics.
authors.affiliation: Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong, Hong Kong, China.
authors.forename: C L
authors.initials: CL
authors.lastname: Wong
authors.forename: H P
authors.initials: HP
authors.lastname: Ho
authors.forename: Y K
authors.initials: YK
authors.lastname: Suen
authors.forename: S K
authors.initials: SK
authors.lastname: Kong
authors.forename: Q L
authors.initials: QL
authors.lastname: Chen
authors.forename: W
authors.initials: W
authors.lastname: Yuan
authors.forename: S Y
authors.initials: SY
authors.lastname: Wu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003199:Computer Systems; D004867:Equipment Design; D019544:Equipment Failure Analysis; D040081:Protein Array Analysis / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis*; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods
chemical_list: D012709:Serum Albumin