Waveguide-based chemo- and biosensors: complex emulsions for the detection of caffeine and proteins

Abstract

Emulsion waveguides: a new modular sensing approach in which complex emulsions serve as efficient transducers in optical evanescent field-based waveguide sensors is reported.

Responsive drop method: quantitativein situdetermination of surfactant effectiveness using reconfigurable Janus emulsions

“…the droplet geometries can be controllably altered after emulsification by triggering changes in the surfactant effectiveness, 15,16 and examples of the latter include stimuli-responsive or cleavable surfactants. 17 Owing to this unique morphological response to targeted chemical stimuli, Janus emulsions have been exploited in a number of applications, including as tunable microlenses, 18 optical waveguides, [19][20][21] scaffolds for the fabrication of anisotropic solid objects, 22,23 motile particle systems, 24,25 and as transducers and signal amplifiers in improved chemo-and biosensing platforms. [26][27][28][29] Herein, we leverage the exquisitely sensitive chemicalmorphological coupling inside Janus emulsions for the development of a new simple and broadly applicable method for the quantitative characterization of surfactants.…”

Dynamic Complex Liquid Crystal Emulsions

“…Optical changes caused by surfactant or analyte triggered changes in droplets' morphology or alignment have demonstrated utility for the detection biomolecules or pathogens. [10][11][12][13][14] Additionally, the dynamic optical properties of these complex colloids have utility as imaging elements wherein micro-lens arrays can be used to project or capture real or virtual images and display variable focal lengths. 15 Colloidal solutions with increasing complex internal organizations can ultimately enable new untapped opportunities, and to this end we are interested in creating colloids containing nanostructured fluids, such as liquid crystals (LCs).…”

Fluorescent Janus emulsions for biosensing of Listeria monocytogenes

“…Specifically agglutination induces strong fluorescence in the sub-PC/F-PBI system when the excitation is performed under total internal reflection conditions using a glass prism at the glass interface (SI Appendix, Fig. S29) (44,45). The present assays readily achieve a detection limit of Listeria of 100 CFUs per mL and can be extended to the detection of different analytes by the utilization of corresponding stable and selective antibodies.…”