Enhancement of the Upconversion Emission by Visible-to-Near-Infrared Fluorescent Graphene Quantum Dots for miRNA Detection

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• 作者：Marco Laurenti ; Miguel Paez-Perez ; Manuel Algarra ; Paulino Alonso-Cristobal ; Enrique Lopez-Cabarcos ; Diego Mendez-Gonzalez ; Jorge Rubio-Retama
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：May 25, 2016
• 年：2016
• 卷：8
• 期：20
• 页码：12644-12651
• 全文大小：594K
• 年卷期：0
• ISSN：1944-8252

文摘

We developed a sensor for the detection of specific microRNA (miRNA) sequences that was based on graphene quantum dots (GQDs) and ssDNA-UCNP@SiO₂. The proposed sensor exploits the interaction between the sp² carbon atoms of the GQD, mainly π–π stacking, and the DNA nucleobases anchored on the upconversion nanoparticles (UCNPs). This interaction brings the GQD to the surface of the ssDNA-UCNP@SiO₂ system, enhancing the upconversion emission. On the other hand, hybridization of the single-stranded DNA (ssDNA) chains anchored on the nanoparticles with their complementary miRNA sequences blocks the capacity of the UCNPs to interact with the GQD through π–π stacking. That gives as result a reduction of the fluorescent enhancement, which is dependent on the concentration of miRNA sequences. This effect was used to create a sensor for miRNA sequences with a detection limit of 10 fM.