Development of Self-Assembled Gold Nanoparticle Bound Amino Hydroxy Mercaptopurine Hybrids as Sensors for DNA Binding

Abstract

A new amphiphilic bio-organic material was developed by conjugating the xanthine oxidase inhibitor, 2-amino-6-hydroxy-8-mercaptopurine (AMHP) with the naturally occurring polyphenol coumaric acid (CA). The formed product, AMHP-CA was allowed to self-assemble at a pH range of 4 through 8. Nanospheres or fibrous assemblies ranging upto micrometers in length were formed, depending upon growth conditions. Furthermore, it was found that the assemblies biomimetically formed gold nanoparticles on its surfaces resulting in AMHP-CA-AuNP hybrids. The DNA sensing ability of the AuNP bound AMHP-CA assemblies was investigated at varying concentrations by studying the changes in conformations of salmon milt DNA by CD spectroscopy and by examining live binding with surface plasmon resonance (SPR) analysis. AuNP bound AMHP-CA assemblies had significantly increased DNA sensing ability and SPR signal compared to binding interactions in the absence of AuNPs. Thus, in this study it was found that AMHP-CA-AuNP assemblies may function as biosensors for DNA detection.