We experimentally demonstrate a label-free sensor based on nanoslotted parallel quadrabeam photonic crystal cavity (NPQC). The NPQC possesses both high sensitivity and high Q-factor. We achieved sensitivity (S) of 451 nm/refractive index unit and Q-factor >7000 in water at telecom wavelength range, featuring a sensor figure of merit >2000, an order of magnitude improvement over the previous photonic crystal sensors. In addition, we measured the streptavidin-biotin binding affinity and detected 10 ag/mL concentrated streptavidin in the phosphate buffered saline solution.
High sensitivity and high Q-factor nanoslotted parallel quadrabeam photonic crystal cavity for real-time and label-free sensing
Daquan Yang, Shota Kita, Feng Liang, Cheng Wang, Huiping Tian, Yuefeng Ji, Marko Lončar, Qimin Quan; High sensitivity and high Q-factor nanoslotted parallel quadrabeam photonic crystal cavity for real-time and label-free sensing. Appl. Phys. Lett. 11 August 2014; 105 (6): 063118. https://doi.org/10.1063/1.4867254
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