Three-dimensional photonic crystal short-pillar architecture for high-performance optical biosensing

Abstract

Numerical analysis of optical biosensors made of very short-pillar (only one or two lattice constants high) liquid-infiltrated photonic crystals is presented. The small pillar height makes these photonic crystals amenable to fabrication by techniques such as nanoimprinting. Our biosensors can detect at least three different analytes (disease markers), individually or combinatorially in a single spectroscopic measurement. The resonance linewidths of our proposed device are narrow enough to accurately identify the relative concentrations of analytes within the biofluid, enabling our device to provide both qualitative and quantitative disease diagnoses. The minimal volume of fluid sample required for diagnosis is set by the micrometer-scale lattice constant of the photonic crystal. Using finite-difference time-domain simulations, we present detailed spectral characteristics for all possible combinations of analyte attachment to the photonic crystal nanopillars.