Geminally biotinylated cyclotriphosphazenes as molecular binding probe

Biotinylated cyclotriphosphazenes polymer (g-BTP) with geminal octopus-like molecular shape has been prepared and characterized by ³¹P-NMR, ¹H-NMR and Matrix-assisted laser desorption ionization-time of flight-mass spectrometry (Maldi-Tof-Ms). Analysis of the size distribution of the complexes showed that the aggregated g-BTP/avidin complexes were rather polydispersed and uniform as compared to complexes formed by random coil biotinylated linear polymer (BLP) and avidin. Binding kinetics studies show that both of g-BTP and BLP can bind avidin very quickly. The binding ability as evaluated by Scatchard plot indicates the binding ability of g-BTP to be about 5.5 times that of BLP.