IMMOBILIZATION AND HYBRIDIZATION OF DNA ON AN ALUMINUM(III) ALKANEBISPHOSPHONATE THIN-FILM WITH ELECTROGENERATED CHEMILUMINESCENT DETECTION

Immobilization of single-stranded (ss) DNA on an electrode covered with an aluminum alkanebisphosphonate film by immersion in an ss-DNA solution was demonstrated with ss-DNA labeled with Ru(bpy)(3)(2+). This was detected by observing the electrogenerated chemiluminescence (ECL) produced upon oxidation in a solution containing tri-n-propylamine. Surface hybridization was shown by immobilization of unlabeled ss-DNA, followed by exposure to a complementary labeled strand of DNA to produce Ru(bpy)(3)(2+)-labeled double-stranded (ds) DNA on the surface. The extent of DNA hybridization was determined by ECL. Hybridization of unlabeled DNA, e.g., poly(dA) and poly(dT), could be detected by treatment with Ru(phen)(3)(2+) and ECL of this species associated with the ds-DNA. in a similar way, an eight-base single strand of DNA was determined by immobilizing it on the film followed by hybridization of the eight-base complementary strand. The surface-immobilized eight-base pair ds-DNA was also detected by observing the ECL of intercalated Ru(phen)(3)(2+).