Common-path phase-shift interferometry surface plasmon resonance imaging system

Abstract

Surface plasmon resonance (SPR) and common-path phase-shift interferometry (PSI) techniques are integrated in a biosensing imaging system for measuring the two-dimensional spatial phase variation caused by biomolecular interactions on a sensing chip without the need for additional labeling. The common-path PSI technique has the advantage of long-term stability, even when it is subjected to external disturbances. Hence the system meets the requirements of the real-time kinetic studies involved in biomolecular interaction analysis. The proposed SPR-PSI imaging system demonstrates a detection limit of a 2 x 10(-7) refractive-index change, a long-term phase stability of 2.5 x 10(-4) pi rms for 4 h, and a spatial phase resolution of 10(-3) pi with a lateral resolution of 100 microm.

Phase‐sensitive surface plasmon resonance biosensors: methodology, instrumentation and applications

“…Here, three approaches to phase-sensitive measurements are possible. In the first approach, called SPR interferometry, phase information is extracted from an interference pattern between the "signal" p-polarized beam, reflected from the SPR-supporting film, and the "reference" beam presented by either an additional p-polarized beam [14][15][16]23,[40][41][42][43] or the unaffected s-polarized component of the same beam [17,19,[44][45][46][47][48][49]. Such approach makes possible the extraction of a pure phase response in sensing or 2D imaging geometries.…”

“…Obviously, this problem can be solved by incorporating variable phase shifting devices for a better phase control. In 2005, Su et al [19] incorporated phase shift interferometry into SPR polarimetry and implemented SPR imaging. In their setup, a liquid crystal phase retarder was incorporated to introduce accurate phase shifts and a two-dimensional CCD camera was used instead of a point photodetector for recording the interference intensities.…”

“…Promising a spectacular improvement of sensitivity of SPR technology, the concept of phasesensitive SPR was later transformed to a series of interferometric, polarimetric and optical heterodyning designs and schemes. Polarimetric and Optical Heterodyning approaches profit from efficient electronic filtering of background noises, whereas advantages of SPR interferometry include a simple optical extraction/visualization of ultra-sensitive phase information and, more importantly, the imaging opportunity due to a good lateral resolution over the surface of the SPR-supporting film [16][17][18][19][20]. The latter option, for example, makes possible parallel detection of thousands of channels, as e.g.…”

Surface Plasmon Resonance Phase-Sensitive Imaging (Spr-Pi) Sensor Based on a Novel Prism Phase Modulator

“…Several years later they applied the piezoelectric stage in a SPR-PI system and obtained a resolution of 8.8 × 10 −7 RIU with different glycerine solutions [18]. In 2005, Su and Chen applied a liquid crystal modulator to induce a phase difference between p-and s-polarization of the light in a SPR-PI sensor [24]. They tested their sensor with nitrogen and argon gases and estimate a detection limit of 2 × 10 −7 RIU with gaseous samples.…”

Dual-channel differential surface plasmon ellipsometry for bio-chemical sensing

“…For example, the association and dissociation of protein-protein binding events can be investigated, allowing further understanding of their interactions to be obtained, and the concentration of an analyte within solution to be determined. Studies investigating bio-chemical reactions constitute only a part of the available SP sensing literature, there are also a number of papers on improving SP sensing techniques, and the quality of the data obtained from them, in order to either reduce detection levels or to enable multi-channel sensing for high-throughput screening Piliarik et al, 2005;Su et al, 2005).…”