分会

第二分会：纳米传感

摘要

本工作基于石墨烯量子点和单宁酸的协同还原和稳定作用，一步法制备得到性质稳定的纳米银-石墨烯量子点复合物（AgNPs@GQDs），并建立紫外吸收-荧光双模式响应的过氧化氢检测新方法。作为一种有效的还原剂，单宁酸可用于AgNPs的生长；氨基化石墨烯量子点（NH2-GQDs）不仅具有良好的荧光性能，同时因其表面具有较多的功能基团（如羟基、氨基、羧基等），可作为良好的还原剂和稳定剂用于制备AgNPs。基于单宁酸和石墨烯量子点的协同作用，通过原位合成法可制备得到AgNPs@GQDs复合物，其中复合物表面的GQDs可保护AgNPs不发生聚集或降解，提高其稳定性，且AgNPs@GQDs具有典型的紫外吸收特性。同时，由于复合物内部发生荧光共振能量转移，表面AgNPs@GQDs的荧光被猝灭。在过氧化氢的作用下，AgNPs@GQDs被氧化为银离子，此时复合物内部的荧光共振能量转移被抑制，释放出NH2-GQDs，其荧光恢复。基于此建立了紫外吸收-荧光双模式检测过氧化氢的新方法。 In this work, the AgNPs@GQDs nanocomposite is prepared based on the one-pot synergistic in-situ growth of AgNPs on tannic acid and amino functionalized graphene quantum dots (TA-NH2-GQDs) complex. TA is an effective reducing agent for the growth of AgNPs. NH2-GQDs not only exhibit fluorescence performance, but also are rich in hydroxyl, amino and carboxyl groups, serving as reducing agent as well as stabilizer for the growth of AgNPs directly. In addition, the assembled NH2-GQDs protect AgNPs@GQDs from aggregation or degradation and improve the stability to a great extent. The as-prepared AgNPs@GQDs exhibit typical UV-vis absorption, while the fluorescence of the assembled NH2-GQDs is quenched by AgNPs through FRET. In the presence of hydrogen peroxide (H2O2), AgNPs@GQDs undergo a degradation, in which Ag0 is oxidized to Ag+ along with the release of TA and NH2-GQDs. Thus, the FRET in the nanocomposite is suppressed. The typical plasma absorption of AgNPs@GQDs at 412 nm decreases and fluorescence at 450 nm increases gradually, achieving a dual-mode H2O2 nanosensor.

关键词

石墨烯量子点;原位合成银纳米颗粒;双模式检测过氧化氢

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