The encapsulation of individual pairs of plasmonic nanoparticles(NPs)in liposomes is introduced as a new strategy for utilizing plasmon coupling to monitor interactions between co-confined NPs in a nanoconfinement tha...The encapsulation of individual pairs of plasmonic nanoparticles(NPs)in liposomes is introduced as a new strategy for utilizing plasmon coupling to monitor interactions between co-confined NPs in a nanoconfinement that ensures high local NP concentrations.We apply the approach to monitor transient binding contacts between noncovalently tethered 55 nm diameter gold NPs,which were functionalized with cytosine(C)-rich DNAs,in acidic and mildly basic buffer conditions.At pH=8,a rich spectral dynamics indicates DNA-mediated transient binding and unbinding of co-confined NPs due to weak attractive interparticle interactions.A decrease in pH from 8 to 4 is observed to favor the associated state for some co-confined NPs,presumably due to a stabilization of the bound dimer configuration through noncanonical C-C^(+)bonds between the DNA-functionalized NPs.Plasmonic nanoemitters whose spectral response switches in response to chemical cues(in this work pH)represent optical transducers with a rich application space in chemical sensing,cell analysis and nanophotonics.展开更多
基金This work was supported by the National Institutes of Health(NIH)through Grant No.R01CA138509(to BMR).
文摘The encapsulation of individual pairs of plasmonic nanoparticles(NPs)in liposomes is introduced as a new strategy for utilizing plasmon coupling to monitor interactions between co-confined NPs in a nanoconfinement that ensures high local NP concentrations.We apply the approach to monitor transient binding contacts between noncovalently tethered 55 nm diameter gold NPs,which were functionalized with cytosine(C)-rich DNAs,in acidic and mildly basic buffer conditions.At pH=8,a rich spectral dynamics indicates DNA-mediated transient binding and unbinding of co-confined NPs due to weak attractive interparticle interactions.A decrease in pH from 8 to 4 is observed to favor the associated state for some co-confined NPs,presumably due to a stabilization of the bound dimer configuration through noncanonical C-C^(+)bonds between the DNA-functionalized NPs.Plasmonic nanoemitters whose spectral response switches in response to chemical cues(in this work pH)represent optical transducers with a rich application space in chemical sensing,cell analysis and nanophotonics.
