Shin Jin Sol, Li Sheng
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 Republic of Korea.
ACS Omega. 2022 Dec 15;7(51):48310-48319. doi: 10.1021/acsomega.2c06498. eCollection 2022 Dec 27.
DNA-immobilized nanoparticle probes show high target specificity; thus, they are employed in various bioengineering and biomedicine applications. When the nanoparticles employed are dye-loaded polymer particles, the resulting probes have the additional benefit of biocompatibility and versatile surface properties. In this study, we construct DNA-immobilized fluorescent polystyrene (PS) nanoparticles through controlled surface reactions. PS nanoparticles with surface carboxyl groups are utilized, and amine-functionalized dye molecules and capture DNAs are covalently immobilized via a one-pot reaction. We show that the surface chemistry employed allows for quantitative control over the number of fluorescent dyes and DNA strands immobilized on the PS nanoparticle surfaces. The nanoparticles thus prepared are then used for DNA detection. The off state of the nanoprobe is achieved by hybridizing quencher-functionalized DNAs (Q-DNAs) to the capture DNAs immobilized on nanoparticle surfaces. Target-DNAs (T-DNAs) are detected by the displacement of the prehybridized Q-DNAs. The nanoprobes show successful detection of T-DNAs with high sequence specificity and long-term stability. They also show excellent detection sensitivity, and the detection limit can be tuned by adjusting the capture DNA-to-dye ratio.
固定有DNA的纳米颗粒探针具有高靶向特异性；因此，它们被用于各种生物工程和生物医学应用中。当所使用的纳米颗粒是负载染料的聚合物颗粒时，所得探针还具有生物相容性和多功能表面性质的额外优点。在本研究中，我们通过可控的表面反应构建了固定有DNA的荧光聚苯乙烯（PS）纳米颗粒。利用具有表面羧基的PS纳米颗粒，通过一锅法反应将胺功能化的染料分子和捕获DNA共价固定。我们表明，所采用的表面化学方法能够对固定在PS纳米颗粒表面的荧光染料和DNA链的数量进行定量控制。然后将如此制备的纳米颗粒用于DNA检测。通过将淬灭剂功能化的DNA（Q-DNA）与固定在纳米颗粒表面的捕获DNA杂交来实现纳米探针的关闭状态。通过预杂交的Q-DNA的置换来检测目标DNA（T-DNA）。纳米探针成功地检测到了具有高序列特异性和长期稳定性的T-DNA。它们还表现出优异的检测灵敏度，并且可以通过调整捕获DNA与染料的比例来调节检测限。
