title: Biosensing using straight long-range surface plasmon waveguides.
abstract: Straight long-range surface plasmon waveguides are demonstrated as biosensors for the detection of cells, proteins and changes in the bulk refractive index of solutions. The sensors consist of 5 μm wide 22 nm thick Au stripes embedded in polymer (CYTOP™) with microfluidic channels etched into the top cladding. Bulk sensing is demonstrated by sequentially injecting six solutions of different refractive indices in 2 × 10(-3) RIU increments; such index steps were detected with a signal-to-noise ratio of ~1000. Selective capture of cells is demonstrated using Au waveguides functionalized with antibodies against blood group A, and red blood cells of group A and O in buffer as positive and negative analyte. Bovine serum albumin in buffer was used to demonstrate protein sensing. A monolayer of bovine serum albumin physisorbed on a carboxyl-terminated self-assembled monolayer on Au was detected with a signal-to-noise ratio of ~300. Overall, the biosensor demonstrated a good capability for detecting bulk changes in solution and for sensing analyte over a very wide range of mass (from cells to proteins). The biosensors are compact, inexpensive to fabricate, and may find use over a wide range of cost-sensitive sensing and detection applications.
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario, Canada.
authors: Oleksiy
authors: O
authors: Krupin
authors: Hamoudi
authors: H
authors: Asiri
authors: Chen
authors: C
authors: Wang
authors: R Niall
authors: RN
authors: Tait
authors: Pierre
authors: P
authors: Berini
mesh_terms: D000017:ABO Blood-Group System; D000096:Acetone / Q000737:chemistry; D000818:Animals; D015374:Biosensing Techniques; D002021:Buffers; D002417:Cattle; D004867:Equipment Design; D004912:Erythrocytes / Q000166:cytology; D006046:Gold / Q000737:chemistry; D006801:Humans; D011108:Polymers / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D012666:Semiconductors; D012709:Serum Albumin / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods; D013997:Time Factors
chemical_list: D000017:ABO Blood-Group System; D002021:Buffers; D011108:Polymers; D011506:Proteins; D012709:Serum Albumin; D000096:Acetone; D006046:Gold