On-demand droplet fusion: a strategy for stimulus-responsive biosensing in solution. Journal Article uri icon



  • A novel strategy is reported for biochemically controlled fusion of oil-in-water (O/W) droplets as an in-solution sensor for biological targets. Inspired by the SNARE complex in cells, the emulsions were stabilized by a combination of phospholipids, phospholipid-poly(ethylene glycol) conjugates, and cholesterol-anchored oligonucleotides. Prior to oligonucleotide binding, the droplets were stable in aqueous media, but hybridization of the oligonucleotides in a zipperlike fashion was shown to initiate droplet fusion. Using image analysis of content mixing of dye-loaded droplets, fusion specificity was studied and optimized as a function of interfacial chemistry. Changing the orientation of the anchored oligonucleotides, using long-chain phospholipids (C18 and C22), and binding a complementary oligonucleotide slowed or even halted fusion completely. Based on these studies, a sensor for the biomarker thrombin was designed using competitive binding of aptamer strands, with droplet fusion increasing as a function of thrombin addition in accordance with a simple binding model, with sensitivity down to 100 nM and with results in as little as 15 min. Future efforts will focus on utilizing this mechanism of content mixing to facilitate highly sensitive detection via modalities such as magnetoresistance or chemiluminescence.

publication date

  • October 21, 2014

has restriction

  • hybrid

Date in CU Experts

  • October 1, 2014 9:00 AM

Full Author List

  • Mohan P; Noonan PS; Nakatsuka MA; Goodwin AP

author count

  • 4

Other Profiles

Electronic International Standard Serial Number (EISSN)

  • 1520-5827

Additional Document Info

start page

  • 12321

end page

  • 12327


  • 30


  • 41