Dual-optofluidic waveguide in-line fiber biosensor for real-time label-free detection of interferon-gamma with...

Temperature cross-sensitivity is a long-standing challenge for most of the in-line fiber optofluidic waveguide biosensors. In this paper, we propose a dual-optofluidic waveguide antiresonant reflecting optical waveguide (ARROW) biosensor for the detection of interferon-gamma (IFN-γ) concentration with temperature compensation. Two Fabry-Perot resonators infiltrated with IFN-γ and NaCl were formed in a hollow core fiber, which generate two resonance dips based on the ARROW model. The optical biosensor for the detection of interferon-gamma (IFN-γ) has been a key research interest in recent years because IFN-γ is an important early biomarker for many serious human diseases. Based on the dual-optofluidic waveguide ARROW biosensor, the IFN-γ concentration can be measured through the modulation of the resonance condition of the ARROW, while the temperature fluctuation can be eliminated due to same thermo-optic coefficients of two infiltration liquids. The experimental results show that the response of the ARROW biosensor can be amplified significantly with the signal-enhanced streptavidin, and the limit of detection of 0.5 ng/ml can be achieved for the IFN-γ concentration. More importantly, the influence of the temperature could be compensated through the referenced resonance dip. The proposed fiber biosensor has a great potential for the real-time detection of IFN-γ concentrations in the fields of health monitoring, cancer prevention, biological engineering, etc.