Atto 520 

Atto fluorescent labels are designed for high sensitivity applications, including single-molecule detection. Atto labels have rigid structures that do not show any cis-trans isomerization. Thus these labels display exceptional intensity with minimal spectral shift on conjugation.
Atto 520 shows a molar extinction of 110,000 and QY of 90% in water (95% in ethanol). Decay time is 3.6 ns.

Employed in confocal fluorescence microscopy to confirm formation of polymer nanoshells;¹ using combined imaging and scanning fluorescence correlation spectroscopy to characterize microsecond emission fluctuation.²

for fluorescence

BioChemika

≥90.0% (HPCE/HPLC)

λ_ex 520 nm; λ_em 540 nm in 0.1 M phosphate pH 7.0

2-8°C

1. A.B. Artyukhin et al., Layer-by-layer electrostatic self-assembly of polyelectrolyte nanoshells on individual carbon nanotubule templates. Langmuir 20, 1442-1448, (2004) abstract

2. Y. Xiao et al., Scanning fluorescence correlation spectroscopy: a tool for probing microsecond dynamics of surface-bound fluorescent species. Anal. Chem. 77, 36-46, (2005) abstract

3