Preparation of novel polypyridyl ruthenium complex polymers with high sensitivity for electrogenerated chemiluminescence via copolymerization.

We report two novel monomers, Ru1mono with one vinyl group, 4-[(4-vinylbenzylformamidyl)-4'-carboxylacid-2,2'-bipyridyl]-bis[2,2'-bipyridyl] ruthenium(II) perchlorate and Ru2mono with two vinyl groups, 4,4'-bis[(4-vinylbenzylformamidyl)-2,2'-bipyridyl]-bis[2,2'-bipyridyl] ruthenium(II) perchlorate. The molecular structures were demonstrated by NMR, mass spectrometry and elemental analysis. Polymers Ru1MVP and Ru2MVP were then co-polymerized under free radical polymerization from Ru1mono or Ru2mono and 4-vinylpyridine with the molar ratio of 9:1, respectively. Electrogenerated chemiluminescence (ECL) of Ru1MVP in a thin film on an electrode has been tested. It increased 17 times relative to cis-Ru(bpy)(2)PVP(10)(2) (RuPVP) reported in the presence of co-reactant tri-n-propylamine (TPA) at the oxidative peak around 1.16 V with scan rate of 100 mV s(-1). Relative to RuPVP ECL of Ru2MVP was 110 times greater with TPA, and 40 times greater with another co-reactant, sodium oxalate. The significant enhancement of ECL and improvement in making a stable film could be expected to lead to an applicable immobilized immunoassay technology via ECL.