A common-path phase-shift interferometry surface plasmon imaging system

Abstract

A biosensing imaging system is proposed based on the integration of surface plasmon resonance (SPR) and common-path phase-shift interferometry (PSI) techniques to measure the two-dimensional spatial phase variation caused by biomolecular interactions upon a sensing chip. The SPR phase imaging system can offer high resolution and high-throughout screening capabilities to analyze microarray biomolecular interaction without the need for additional labeling. With the long-term stability advantage of the common-path PSI technique even with external disturbances such as mechanical vibration, buffer flow noise, and laser unstable issue, the system can match the demand of real-time kinetic study for biomolecular interaction analysis (BIA). The SPR-PSI imaging system has achieved a detection limit of 2×10 -7 refraction index change, a long-term phase stability of 2.5x10 -4 π rms over four hours, and a spatial phase resolution of 10 -3 π with a lateral resolution of 100µm.

Photonic crystal fiber based plasmonic sensors

“…Surface plasmon resonance (SPR) sensors have attracted lots of interests due to their unique capabilities such as high sensitivity and wide range of applications in environment monitoring [1], food safety [2,3], water testing [4], liquid detection [5,6], gas detection [7,8], biosensing [9,10], and medical diagnostics [11], including drug detection [12,13], bioimaging [14], biological analyte [15,16], and chemical detection [16][17][18][19] (Figure 1). SPR effects are also utilized in optoelectronic devices such as optical tunable filters [20,21], modulators [22,23], SPR imaging [24,25], and thin-film thickness monitoring [26,27]. Besides the SPR techniques some other optical sensing techniques are also available such as microring resonators, waveguides, and resonant mirror [28,29].…”