TY - JOUR
T1 - DNA-coated functional oil droplets
AU - Caciagli, Alessio
AU - Zupkauskas, Mykolas
AU - Levin, Aviad
AU - Knowles, Tuomas P. J.
AU - Mugemana, Clément
AU - Bruns, Nico
AU - O'Neill, Thomas
AU - Frith, William J.
AU - Eiser, Erika
PY - 2018/8/28
Y1 - 2018/8/28
N2 - Many industrial soft materials include oil-in-water (O/W) emulsions at the core of their formulations. By using tuneable interface stabilizing agents, such emulsions can self-assemble into complex structures. DNA has been used for decades as a thermoresponsive, highly specific binding agent between hard and, recently, soft colloids. Up until now, emulsion droplets functionalized with DNA had relatively low coating densities and were expensive to scale up. Here, a general O/W DNA-coating method using functional nonionic amphiphilic block copolymers, both diblock and triblock, is presented. The hydrophilic poly(ethylene glycol) ends of the surfactants are functionalized with azides, allowing for efficient, dense, and controlled coupling of dibenzocyclooctane-functionalized DNA to the polymers through a strain-promoted alkyne-azide click reaction. The protocol is readily scalable due to the triblock's commercial availability. Different production methods (ultrasonication, microfluidics, and membrane emulsification) are used with different oils (hexadecane and silicone oil) to produce functional droplets in various size ranges (submicron, ∼20 and >50 μm), showcasing the generality of the protocol. Thermoreversible submicron emulsion gels, hierarchical "raspberry" droplets, and controlled droplet release from a flat DNA-coated surface are demonstrated. The emulsion stability and polydispersity is evaluated using dynamic light scattering and optical microscopy. The generality and simplicity of the method opens up new applications in soft matter, biotechnological research, and industrial advances.
AB - Many industrial soft materials include oil-in-water (O/W) emulsions at the core of their formulations. By using tuneable interface stabilizing agents, such emulsions can self-assemble into complex structures. DNA has been used for decades as a thermoresponsive, highly specific binding agent between hard and, recently, soft colloids. Up until now, emulsion droplets functionalized with DNA had relatively low coating densities and were expensive to scale up. Here, a general O/W DNA-coating method using functional nonionic amphiphilic block copolymers, both diblock and triblock, is presented. The hydrophilic poly(ethylene glycol) ends of the surfactants are functionalized with azides, allowing for efficient, dense, and controlled coupling of dibenzocyclooctane-functionalized DNA to the polymers through a strain-promoted alkyne-azide click reaction. The protocol is readily scalable due to the triblock's commercial availability. Different production methods (ultrasonication, microfluidics, and membrane emulsification) are used with different oils (hexadecane and silicone oil) to produce functional droplets in various size ranges (submicron, ∼20 and >50 μm), showcasing the generality of the protocol. Thermoreversible submicron emulsion gels, hierarchical "raspberry" droplets, and controlled droplet release from a flat DNA-coated surface are demonstrated. The emulsion stability and polydispersity is evaluated using dynamic light scattering and optical microscopy. The generality and simplicity of the method opens up new applications in soft matter, biotechnological research, and industrial advances.
KW - oil-in-water
KW - emulsions
KW - DNA
UR - http://www.scopus.com/inward/record.url?scp=85052307357&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.8b01828
DO - 10.1021/acs.langmuir.8b01828
M3 - Article
C2 - 30086643
AN - SCOPUS:85052307357
SN - 0743-7463
VL - 34
SP - 10073
EP - 10080
JO - Langmuir
JF - Langmuir
IS - 34
ER -