Controlled multilayer films of sulfonate-capped gold nanoparticles/thionine used for construction of a reagentless bienzymatic glucose biosensor
Controlled multilayer films of sulfonate-capped gold nanoparticles/thionine used for construction of a reagentless bienzymatic glucose biosensor
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DOI：
10.1016/j.electacta.2007.06.007
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发表时间：
2007-09
影响因子：
6.6
通讯作者：
Yingying Sun;Yu Bai;Weiwei Yang;Changqing Sun
中科院分区：
文献类型：
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作者：
Yingying Sun;Yu Bai;Weiwei Yang;Changqing Sun
提出了一种新型的无试剂双酶传感器，可在低工作电位下无干扰地测定葡萄糖。双酶传感器是通过将高碘酸氧化葡萄糖氧化酶（IO 4 −-GOx）和辣根过氧化物酶（HRP）共价连接在磺酸盐覆盖的金纳米颗粒/硫代磷酸盐（SCGNP/TH）的受控多层膜上制成的。采用逐层沉积法（LBL），通过静电和共价相互作用将SCGNP和TH交替沉积在金电极上。SCGNP可以大大提高TH的固定量，并保证整个结构的良好导电性。紫外-可见吸收光谱和电化学测试结果表明，所得多层膜具有三维导电性和多孔性，以LBL构型引入的TH具有良好的电活性。因此，这种超结构可以为双酶传感器的构建提供理想的基质，其中TH分子充当电子传递的介体。将IO 4 −-GOx和HRP共价连接到多层前体膜上后，所得生物传感器对葡萄糖表现出良好的电催化响应，并且电催化响应随TH层数的增加而增加。这表明，双酶传感器的分析性能，如灵敏度和检测限，可以通过调节沉积的SCGNP/TH双层的数量来调整到所需的水平。此外，由于工作电位较低，避免了尿酸、抗坏血酸和对乙酰氨基酚等电氧化物的干扰，提高了传感器的选择性。该传感器具有良好的葡萄糖检测性能，响应时间小于20 s，灵敏度为3.8μAmM−1cm− 2，检测限为3.5×10− 5 M。
A novel reagentless bienzymatic sensor for the determination of glucose in the low working potentials without interference is proposed. The bienzymatic sensor was fabricated by covalently attachment of periodate-oxidized glucose oxidase (IO4−-GOx) and horseradish peroxidase (HRP) on controlled multilayer films of sulfonate-capped gold nanoparticles/thionine (SCGNPs/TH). Using the layer-by-layer method (LBL), SCGNPs and TH were deposited alternately on the gold electrode through the electrostatic and covalent interactions. SCGNPs could greatly enhance the amount of immobilized TH and ensure the good conductivity of the whole structure. UV–vis absorption spectroscopy and electrochemical methods showed that the resulting multilayer films were tridimensional conductive and porous, and TH incorporated in LBL configuration had well electroactive performance. Such superstructures can thus provide an ideal matrix for the construction of bienzymatic sensor, where TH molecules acted as a mediator for electron transfer. After IO4−-GOx and HRP were covalently attached to the multilayer precursor film, the resulting biosensor exhibited good electrocatalytical response toward glucose and that the electrocatalytical response increased with the number of TH layers. This suggested that the analytical performance such as sensitivity and detection limit of the bienzymatic sensors could be tuned to the desired level by adjusting the number of deposited SCGNPs/TH bilayers. Furthermore, because of the low working potentials, the interference from other electro-oxidizable compounds (such as uric acid, ascorbic acid and acetaminophen) was avoided, which improved the selectivity of the biosensors. The biosensor constructed with six bilayers of SCGNPs/TH showed a good performance of glucose detection with a fast response less than 20s, acceptable sensitivity of 3.8μAmM−1cm−2and the detection limit of 3.5×10−5M.