Immobilization of a naphthalene diimide-DNA complex on the gold through dithiolane moieties

Naphthalene diimide 1 having two dithiolane moieties at its substituted termini was newly synthesized to immobilize double stranded DNA through dithiolane moieties of 1. Double stranded DNA could be immobilized on the gold surface of a quartz crystal microbalance (QCM) chip after binding 1. Once immobilized, the complex will serve as a hybridization marker based on its frequency decrease. QCM experiments showed that a DNA duplex with a 24-meric single stranded region also could be immobilized on the gold surface of a QCM chip and subsequent frequency decrease was observed after hybridization with a 24-meric complementary DNA, but not with non-complementary DNA, indicating specific hybridization. This result reveals that 1 provides a new immobilization method for intact DNA on gold and that the immobilized DNA can hybridize with target DNA.