Efficient Colorimetric pH Sensor Based on Responsive Polymer-Quantum Dot Integrated Graphene Oxide
Efficient Colorimetric pH Sensor Based on Responsive Polymer-Quantum Dot Integrated Graphene Oxide
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DOI：
10.1021/nn406657b
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发表时间：
2014-03-01
期刊：
影响因子：
17.1
通讯作者：
Kim, Bumjoon J.
中科院分区：
文献类型：
--
作者：
Paek, Kwanyeol;Yang, Hyunseung;Kim, Bumjoon J.
在本文中，我们报告了一个多功能平台的开发，高效和稳定的氧化石墨烯（GO）为基础的光学传感器，具有独特的比率颜色响应。为了证明该平台的适用性，我们制造了一种比色的，基于GO的pH传感器，其响应于广泛的pH变化。我们的传感系统基于集成在单个GO片（MQD-GO）上的响应聚合物和量子点（QD）混合物，GO在水中提供优异的信噪比和高分散稳定性。蓝色和橙子发光量子点的光致发光MOD-GO中的BQDs和OQDs可以通过多聚核苷酸的不同pH响应性连接体独立地控制。（丙烯酸）（PAA）（pK（a）= 4.5）和聚（2-乙烯基吡啶）（P2 VP）（pK（a）= 3.0），其可以调节从BQD到GO和从OQD到GO的福斯特共振能量转移的效率，分别因此，在宽范围的pH值内，MOD-GO的颜色从橙子变为近白色再变为蓝色。通过时间分辨荧光和动态光散射的测量阐明了MQD-GO传感器的pH依赖性响应的详细机制。此外，MOD-GO传感器在纯水中表现出优异的可逆性和高分散稳定性，表明我们的系统是生物和环境应用的理想平台。我们的比色GO为基础的光学传感器可以很容易地扩展到各种其他多功能，GO为基础的传感器，通过使用交替刺激响应聚合物。
In this paper, we report the development of a versatile platform for a highly efficient and stable graphene oxide (GO)-based optical sensor that exhibits distinctive ratiometric color responses. To demonstrate the applicability of the platform, we fabricated a colorimetric, GO-based pH sensor that responds to a wide range of pH changes. Our sensing system is based on responsive polymer and quantum dot (QD) hybrids integrated on a single GO sheet (MQD-GO), with the GO providing an excellent signal-to-noise ratio and high dispersion stability in water. The photoluminescence emissions of the blue and orange color-emitting QDs (BQDs and OQDs) in MOD-GO can be controlled independently by different pH-responsive linkers of poly(acrylic acid) (PAA) (pK(a) = 4.5) and poly(2-vinylpyridine) (P2VP) (pK(a) = 3.0) that can tune the efficiencies of Forster resonance energy transfer from the BQDs to the GO and from the OQDs to the GO, respectively. As a result, the color of MOD-GO changes from orange to near-white to blue over a wide range of pH values. The detailed mechanism of the pH-dependent response of the MQD-GO sensor was elucidated by measurements of time-resolved fluorescence and dynamic light scattering. Furthermore, the MOD-GO sensor showed excellent reversibility and high dispersion stability in pure water, indicating that our system is an ideal platform for biological and environmental applications. Our colorimetric GO-based optical sensor can be expanded easily to various other multifunctional, GO-based sensors by using alternate stimuli-responsive polymers.