Janus emulsions for the detection of bacteria
- Resource Type
- Authors
- Paulina Kaplonek; Timothy M. Swager; Suchol Savagatrup; Peter H. Seeberger; Qifan Zhang
- Source
- ACS Central Science
ACS Central Science, Vol 3, Iss 4, Pp 309-313 (2017)
- Subject
- Pathogen detection
General Chemical Engineering
Mannose
02 engineering and technology
010402 general chemistry
medicine.disease_cause
01 natural sciences
lcsh:Chemistry
chemistry.chemical_compound
medicine
Janus
Escherichia coli
Chromatography
biology
Lectin
General Chemistry
021001 nanoscience & nanotechnology
biology.organism_classification
0104 chemical sciences
Agglutination (biology)
lcsh:QD1-999
chemistry
Emulsion
biology.protein
Biophysics
0210 nano-technology
Bacteria
Research Article
- Language
- English
Janus emulsion assays that rely on carbohydrate–lectin binding for the detection of Escherichia coli bacteria are described. Surfactants containing mannose are self-assembled at the surface of Janus droplets to produce particles with lectin binding sites. Janus droplets orient in a vertical direction as a result of the difference in densities between the hydrocarbon and fluorocarbon solvents. Binding of lectin to mannose(s) causes agglutination and a tilted geometry. The distinct optical difference between naturally aligned and agglutinated Janus droplets produces signals that can be detected quantitatively. The Janus emulsion assay sensitively and selectively binds to E. coli at 104 cfu/mL and can be easily prepared with long-time stability. It provides the basis for the development of inexpensive portable devices for fast, on-site pathogen detection.
Janus emulsions stabilized by carbohydrate surfactants agglutinate in the presence of proteins or bacteria. Optical changes can be detected by a smart phone qualitatively and can also be processed to quantify the amount of analyte.