7 Plasmon-Associated Control of Chemical Reaction at Nanometer …
121
this study, we employed stochastic switching for fluorescence localization, so-called
dSTORM technique together with remote excitation [16, 17]. Fluorescent dyes were
attached to the AgNW surface via a bulky bio-conjugation to prevent direct contact
between fluorophore and metal (Fig. 7.4a). The dye Alexa647 was chosen as the label
since excitation light intensity can modify its rate of stochastic switching between
fluorescent and non-fluorescent states in appropriate buffer conditions [18].
Fig. 7.4 a Schematic of the binding of Alexa647 to AgNWs. b Fluorescence image of an Alexa647bound AgNW under wide-field excitation. c Absorption (blue curve) and emission (red curve) of
Alexa647 in bulk solution. The fluorescence spectrum of an Alexa647-bound AgNW (black dots)
and a bare AgNW (greens dots) is also included. d–g High resolution reconstructed images of
AgNWs following wide-field excitation assuming that each emission spot is due to a single Alexa647
molecule localized at its centroid. d, e Localized single-molecule density maps for 110 and 250 nm
diameter nanowires, respectively as shown in SEM images inset. f, g Localized single-molecule
intensity maps. Figure reproduced with permission from Ref. [6]
121
this study, we employed stochastic switching for fluorescence localization, so-called
dSTORM technique together with remote excitation [16, 17]. Fluorescent dyes were
attached to the AgNW surface via a bulky bio-conjugation to prevent direct contact
between fluorophore and metal (Fig. 7.4a). The dye Alexa647 was chosen as the label
since excitation light intensity can modify its rate of stochastic switching between
fluorescent and non-fluorescent states in appropriate buffer conditions [18].
Fig. 7.4 a Schematic of the binding of Alexa647 to AgNWs. b Fluorescence image of an Alexa647bound AgNW under wide-field excitation. c Absorption (blue curve) and emission (red curve) of
Alexa647 in bulk solution. The fluorescence spectrum of an Alexa647-bound AgNW (black dots)
and a bare AgNW (greens dots) is also included. d–g High resolution reconstructed images of
AgNWs following wide-field excitation assuming that each emission spot is due to a single Alexa647
molecule localized at its centroid. d, e Localized single-molecule density maps for 110 and 250 nm
diameter nanowires, respectively as shown in SEM images inset. f, g Localized single-molecule
intensity maps. Figure reproduced with permission from Ref. [6]