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چکیده
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Gold nanoparticles (AuNPs) have been extensively employed as nanoscale-based platforms in biological studies andGold nanoparticles (AuNPs) have been extensively employed as nanoscale-based platforms in biological studies and molecular diagnosis for rapid detection due to their unique physiochemical properties such as intrinsic chemical stability and biocompatibility. It has been reported that DNA interactions can be used to induce nanoparticle aggregation. In this vein, nucleic acid targets (RNA or DNA) have been widely detected using single strand oligonucleotide-functionalized AuNPs (DNA–AuNPs) systems. So DNA–AuNPs which can recognize the target of interest have been designed for detection of the complementary target DNA sequence [1-3]. Here, we utilized a DNA-directed assembly strategy for the colorimetric sensing of HIV-1 viral nucleic acids. By designing a proper self-complimentary linker AuNPs functionalized with oligonucleotides (DNA-AuNPs) could be assembled into an integrated network. The linker oligonucleotide is complementary to the strands bound on AuNPs and has self-complementary sequences which are responsible for the interactions between gold nanoparticles. Each particle can bind to every other particle through base pairing interactions in the single-component system. Our strategy utilizes AuNPs functionalized by oligonucleotides with unique sequences present on the HIV-1 RNA virus and linker strands with sequences capable of forming self complementary. The assembly process and the following significant color change from red-to-very low pink occur in the absence of target HIV-1 viral nucleic acids. However, in the presence of the target viral nucleic acids, the linker probe, is simply duplexed and cannot be linked to the DNA-AuNPs. Therefore, the solution color will remain red. [1] Mirkin, C. A.; Letsinger, R. L.; Mucic, R. C.; Storhoff, J. J. Nature, 382, 607-609 (1996) [2] Park, S. Y.; Lytton-Jean, A. K. R.; Lee, B.; Weigand, S.; Schatz, G. C.; Mir
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