Achyuthan Komandoor E, McClain Jaime L, Zhou Zhijun, Whitten David G, Branch Darren W
Biosensors and Nanomaterials Department, Sandia National Laboratories, Albuquerque, NM, USA.
Anal Sci. 2009 Apr;25(4):469-74. doi: 10.2116/analsci.25.469.
We utilized self-assembly of cyanine chromophores to study the conformational changes in various types of nucleic acid scaffolds: single and double stranded DNA, linear or circular DNA and RNA. We identified a chromophore that became highly fluorescent after aggregating upon nucleic acids. Fluorescence from the aggregate was instantaneous after self-assembly. Temporal emission profiles displayed a biphasic trend demonstrating kinetic dependence for assembly and disassembly. Absorption spectra of the aggregate showed a red-shifted "shoulder" peak indicative of J-aggregate. Fluorescence from J-aggregates was also red-shifted. We utilized cyanine self-assembly to quantize various nucleic acids. The limits of detection and quantization for psiX174 DNA were 3 and 9 fmol, respectively. We similarly determined the sensitivity for various nucleic acids and established the optimum conditions for self-assembly. Collectively, the effects of methanol, salt, and full width at half maximum for cyanine fluorescence on DNA or carboxymethylamylose scaffolds, all suggested noncovalent, electrostatic, and hydrophobic forces were involved in supramolecular self-assembly. Our results facilitate a better understanding of supramolecular self-assembly.
单链和双链DNA、线性或环状DNA以及RNA。我们鉴定出一种发色团，它在聚集于核酸上后会发出强烈荧光。自组装后，聚集体的荧光瞬间产生。时间发射曲线呈现出双相趋势，表明组装和解组装存在动力学依赖性。聚集体的吸收光谱显示出一个红移的“肩”峰，这表明形成了J-聚集体。J-聚集体的荧光也发生了红移。我们利用花菁自组装来定量各种核酸。psiX174 DNA的检测限和定量限分别为3 fmol和9 fmol。我们同样确定了各种核酸的灵敏度，并确定了自组装的最佳条件。总体而言，甲醇、盐以及花菁荧光半高宽对DNA或羧甲基直链淀粉支架的影响，都表明非共价、静电和疏水力参与了超分子自组装。我们的结果有助于更好地理解超分子自组装。
