Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland; Department of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland.
Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland.
J Colloid Interface Sci. 2018 Mar 15;514:479-490. doi: 10.1016/j.jcis.2017.12.060. Epub 2017 Dec 24.
Fluorescence resonance energy transfer (FRET) system based on functionalized CdTe-guanine and AuNPs-cytosine bioconjugates for the model nucleobase - guanine detection was developed. Thioglycolic acid coated cadmium telluride quantum dots (QDs) conjugated with guanine and sodium 3-mercapto-1-propanesulfonate stabilized gold nanoparticles (AuNPs) capped by cytosine were obtained and fully characterized. Successful formation of the materials was confirmed by UV-Vis, fluorescence and FTIR spectroscopies. Composition of the conjugates was also characterized with elemental analysis and XPS. By employing a guanine-cytosine interaction the bonding between these complementary nucleobases attached to the nanoparticles leads to the formation of QDs-guanine-AuNPs-cytosine assembly, with the size about 7 nm as demonstrated using atomic force microscopy. That enables an effective FRET from functionalized QDs to AuNPs since both, the required distance and the spectral characteristics of donor-acceptor pair were secured. However, it was shown that in the presence of guanine-model molecule which inhibits the interaction between conjugated QDs and AuNPs the FRET is efficiently hampered. Thus monitoring the changes in the restoring fluorescence signal allows to assay the free guanine concentration. Importantly, we have demonstrated the sensitivity and selectivity of the obtained FRET-based system towards guanine. Moreover, in order to confirm the feasibility of the proposed material for nucleobase detection in the real biological samples the developed nanoparticles were also evaluated under simulated urine conditions. The presented strategy of FRET-based conjugated system preparation might be easily used for the development of another nucleobases selective detection and thus opens many possibilities for the determination of biomolecules in the real samples.
基于功能化 CdTe-鸟嘌呤和 AuNPs-胞嘧啶生物缀合物的荧光共振能量转移 (FRET) 系统被开发用于模型碱基-鸟嘌呤的检测。获得了巯基丙酸修饰的碲化镉量子点 (QDs) 与鸟嘌呤和 3-巯基-1-丙磺酸稳定的金纳米粒子 (AuNPs) 与胞嘧啶结合，并对其进行了充分的表征。成功合成的材料通过紫外-可见光谱、荧光光谱和傅里叶变换红外光谱得到了证实。通过元素分析和 XPS 对缀合物的组成进行了表征。通过利用鸟嘌呤-胞嘧啶相互作用，将连接到纳米粒子上的这些互补碱基之间的键合导致形成 QDs-鸟嘌呤-AuNPs-胞嘧啶组装体，其大小约为 7nm，如原子力显微镜所示。这使得从功能化 QDs 到 AuNPs 的有效 FRET 成为可能，因为所需的距离和供体-受体对的光谱特征都得到了保证。然而，研究表明，在存在鸟嘌呤-模型分子的情况下，它会抑制共轭 QDs 和 AuNPs 之间的相互作用，从而有效地阻碍了 FRET。因此，监测恢复荧光信号的变化可以测定游离鸟嘌呤的浓度。重要的是，我们已经证明了所获得的基于 FRET 的系统对鸟嘌呤的灵敏度和选择性。此外，为了证实所提出的材料在真实生物样品中检测碱基的可行性，还在模拟尿液条件下对纳米粒子进行了评估。基于 FRET 的共轭系统制备策略可以很容易地用于开发另一种碱基选择性检测方法，从而为在真实样品中测定生物分子提供了许多可能性。
