Visual observation of avidin–biotin affinity by fluorescent G4.5 poly(amidoamine) dendrimer

An air-treated G4.5 poly(amidoamine) (PAMAM) dendrimer displayed the enhanced fluorescence enough to be utilized as a fluorescence marker to visualize avidin–biotin affinity: On a fluorescence microscopic image, the avidin labeled by a fluorescent G4.5 PAMAM dendrimer was observed to be selectively bound on the biotin pattern that was prepared by amide-bonding of biotin on a carboxylic acid-terminated self-assembled monolayer and in turn by UV-irradiation with a photomask on the monolayer.