Photoelectrochemical aptasensing of thrombin based on multilayered gold nanoparticle/graphene-TiO2 and enzyme functionalized graphene oxide nanocomposites
Photoelectrochemical aptasensing of thrombin based on multilayered gold nanoparticle/graphene-TiO2 and enzyme functionalized graphene oxide nanocomposites
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基于多层金纳米颗粒/石墨烯-TiO2和酶功能化氧化石墨烯纳米复合材料的凝血酶光电化学适体传感
DOI：
10.1016/j.electacta.2017.07.179
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发表时间：
2017
影响因子：
6.6
通讯作者：
Yao Shouzhuo
中科院分区：
文献类型：
--
作者：
Wang Linping;Meng Yue;Zhang Yue;Zhang Chunxiu;Xie Qingji;Yao Shouzhuo
采用聚二烯丙基二甲基氯化铵（PDDA）辅助煅烧结合层层组装技术制备了一种新型的多层金纳米颗粒修饰石墨烯（GR）-TiO 2异质纳米结构（（AuNPs）x/GR-TiO 2）三元等离子体光催化剂。由于电子导电GR片和等离子体AuNPs的协同作用，TiO 2的电荷分离效率显著提高。与裸TiO 2和GR-TiO 2相比，（AuNPs）2/GR-TiO 2的光电流强度显著增强（裸TiO 2的6倍和GR-TiO 2的3倍）。以（AuNPs）2/GR-TiO 2固定的适配体1为捕获探针，氧化石墨烯、辣根过氧化物酶（HRP）和AuNPs三重标记的适配体2（GO-HRP-AuNPs-apt 2）为检测探针，制备了夹心式凝血酶光电化学适配体传感器。基于HRP催化H_2O_2氧化4-氯-1-萘酚在传感器表面生成绝缘产物，阻碍电子供体（抗坏血酸）向电极表面的电子转移，从而使光电流强度降低，实现凝血酶的检测。将HRP共价固定在GO上可以有效地提高HRP酶的负载量，从而提高传感器的灵敏度。在最佳条件下，线性范围为0.05-110 pM，检测限（LOD）为0.02 pM（S/N= 3）。该传感器已成功用于血清样品中凝血酶的检测。
A new ternary plasmonic photocatalyst based on multilayered gold nanoparticles decorated graphene (GR)-TiO2heteronanostructure ((AuNPs)x/GR-TiO2) was fabricated via a simple poly(diallyldimethylammonium chloride) (PDDA) assisted calcination process in combination with the layer-by-layer (LbL) assembly technique. A remarkably enhanced charge separation efficiency of TiO2was obtained due to the synergistic effect of electron-conducting GR sheets and plasmonic AuNPs. Compared with bare TiO2and GR-TiO2, the as-prepared (AuNPs)2/GR-TiO2showed significantly enhanced photocurrent intensity (6-fold of bare TiO2and 3-fold of GR-TiO2). A sandwich thrombin photoelectrochemical aptasensor was fabricated by using (AuNPs)2/GR-TiO2immobilized aptamer 1 as the capture probe and graphene oxide, horseradish peroxidase (HRP), and AuNPs triple-labeled aptamer 2 (GO-HRP-AuNPs-apt 2) as the detection probe. On the basis of HRP catalyzed oxidation of 4-chloro-1-naphthol by H2O2to yield an insulating product on the transducer surface that obstructs the electron transfer of the electron donor (ascorbic acid) to the electrode surface, the detection of thrombin can be carried out by the decrement of photocurrent intensity. The covalent immobilization of HRP on GO can effectively improve the HRP enzyme loading and thus the sensitivity of the sensor. Under the optimum conditions, a linear response was obtained over the range of 0.05–110 pM, with a limit of detection (LOD) of 0.02 pM (S/N= 3). The sensor was successfully used for detection of thrombin in serum samples.