Dynamic Complex Emulsions as Amplifiers for On-Chip Photonic Cavity-Enhanced Resonators.
Despite the recent emergence of microcavity resonators as label-free biological and chemical sensors, practical applications still require simple and robust methods to impart chemical selectivity and reduce the cost of fabrication. We introduce the use of hydrocarbon-in-fluorocarbon-in-water (HC/FC/W) double emulsions as a liquid top cladding that expands the versatility of optical resonators as chemical sensors. The all-liquid complex emulsions are tunable droplets that undergo dynamic and reversible morphological transformations in response to a change in the chemical environment (e.g., exposure to targeted analytes). This chemical-morphological coupling drastically modifies the effective refractive index, allowing the complex emulsions to act as a chemical transducer and signal amplifier. We detect this large change in the refractive index by tracking the shift of the enveloped resonant spectrum of a silicon nitride (Si3N4) racetrack resonator-based sensor, which correlates well with a change in the morphology of the complex droplets. This combination of soft materials (dynamic complex emulsions) and hard materials (on-chip resonators) provides a unique platform for liquid-phase, real-time, and continuous detection of chemicals and biomolecules for miniaturized and remote, environmental, medical, and wearable sensing applications.
['Savagatrup|Suchol|S|0000-0002-8286-8836', 'Ma|Danhao|D|', 'Zhong|Huikai|H|', 'Harvey|Kent S|KS|', 'Kimerling|Lionel C|LC|', 'Agarwal|Anuradha M|AM|', 'Swager|Timothy M|TM|0000-0002-3577-0510']
D004655:Emulsions D055095:Optics and Photonics D017785:Photons D012031:Refractometry D014159:Transducers
complex emulsions chemical sensor SiN photonics photonic sensor ring resonator cavity