We demonstrate Photonic Resonator Absorption Microscopy in which plasmonic nanoparticles are easily detected through hybrid resonant coupling when attached to a photonic crystal. The approach is used to detect miRNA cancer biomarkers with digital precision and 100 aM detection limits.
Three-dimensional hydrodynamic focusing promises to enhance detection capabilities of optofluidic sensors, enabling low concentration interrogation with higher confidence, critical for disease diagnosis. Novel 3DHDF designs with optofluidic channel diameters in the range of ten microns are evaluated, predicting detection enhancement of up to 3.54 times.
Free space top-down illumination of liquid-core waveguides in an optofluidic chip is implemented by milling slits into a metal layer covering the waveguide channel. Detection of single microbeads with excellent signal-to-noise ratio is demonstrated for different milling depths.