The Thiolated DNA Modification And Self-assemble Of Gold Nanorods And Gold Nano-bipyramids

Gold nanorod (GNR) has attracted great attention for their special chemicaland physical properties. GNR has great surface plasmonic resonce (SPR),especially at the tip of GNR. Certain frequency waves will enhance great localelectric-field at the tip of GNR, due to the very high density of free electrons.Gold bipyramid (GBP), because of the special shape, has a stronger SPR at thetip of GBP due to the higher density of free electrons. Theoretical calculationsindicated that GBPs own much higher refractive index sensitivity than shortnanorods, which cause much larger local electric-field than GNR. However, theresearch about SPR of GBP is still less so far, and it is great important to study theGBP modified with thiolated DNA and its self-assembled structure in view of theacademic significance and the potential application value of GBP.This paper mainly discussed the factors about the modifications of GNR andGBP with thiolated DNA. Meanwhile, the mechanism about GBP modified withthiolated DNA and the self-assembled structure of GBP is discussed in detail.1. Thiolated DNA molecules were successfully attached to GNRs at low pHvalue through the strong interactions between thiol groups and the surface of GNRs.This procedure lasted for only5min which was shorter than any other methodsreported so far. Moreover, this process was much simpler than normal methods, andthe amount of thioled DNA was much less. In addition, GNR satellite structure wasassembled using this fast functionalization method.2. It is the first time to modify GBP by thiolated DNA, and much stableGBP-DNA nanoparticles were obtained. The factors in functionalization of GBPwere discussed, and the fast method in GBP functionalization was proposed.3. It is the first time to obtain GBP satellite structure (in TBE buffer,100mMNaCl) through the combination of GBP with gold nanoparticles, and both allmodified by thiolated DNA.