Gold-nanoparticle-cored polyferrocenyl dendrimers: Modes of synthesis and functions as exoreceptors of biologically important anions and re-usable redox sensors

Polyamidoferrocenylalkylthiolate-Au nanoparticles (AuNP) and AuNP-cored polyferrocenyl dendrimers have been assembled either by the ligand-substitution method from dodecanethiolate-AuNP (AB(3) units) or Brust-type direct synthesis from a 1-1 mixture of dodecanethiol and dendronized thiol (AB(9) units). The AuNP-cored polyferrocenyl dendrimers are a new type of dendrimers with a AuNP core. AuNPs containing a nonasilylferrocenyl dendron have been synthesized; they bear respectively 180 and 360 ferrocenyl units at the periphery. These AuNPs selectively recognize the anions H2PO4- and adenosine-5 '-triphosphate (ATp(2-)) with a positive dendritic effect. Recognition is monitored by the appearance of a new wave at a less positive potential in cyclic voltammetry (CV). These AuNP-cored polyferrocenyl dendrimers can form robust modified electrodes that serve as re-usable sensors of ATp(2-) by simple washing with CH2O2.