title: Phase-stepping technique for highly sensitive microscopic surface plasmon resonance biosensor.
abstract: In this paper, the phase-stepping technique is applied to improve a phase-sensitive surface plasmon resonance biosensor based on differential interferometry between focused radially polarized and azimuthally polarized cylindrical vector beams. Detailed analysis is presented for the phase-stepping method, and the least squares unwrapping algorithm is employed to detect the phase distribution in correspondence to the refractive index of sample. Benefiting from the phase-stepping technique, both the measurement speed and sensitivity are improved significantly. The proposed sensor maintains high sensitivity of 9.4×10-7RIU/1° and a wide dynamic range of 0.35 RIU simultaneously. Furthermore, the real-time binding reaction process of bovine serum albumin with antibody is monitored to verify the system for potential biological applications.
authors.forename: Chonglei
authors.initials: C
authors.lastname: Zhang
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Yijia
authors.initials: Y
authors.lastname: Wang
authors.forename: Siwei
authors.initials: S
authors.lastname: Zhu
authors.forename: Changjun
authors.initials: C
authors.lastname: Min
authors.forename: X-C
authors.initials: XC
authors.lastname: Yuan
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002417:Cattle; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000032:analysis* / Q000276:immunology; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D012710:Serum Albumin, Bovine