Bimetallic PtM (M = Pd, Ir) nanoparticle decorated multi-walled carbon nanotube enzyme-free, mediator-less amperometric sensor for H₂O₂

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• 作者：Kuan-Jung Chen^a ; K. Chandrasekara Pillai^a ; John Rick^a ; Chun-Jern Pan^a ; Shih-Han Wang^b ; Chung-Chiun Liu^c ; Bing-Joe Hwang^a ; ^d ; ^{bjh@mail.ntust.edu.tw}
• 关键词：Pt-based bimetallic nanoparticles (NPs) ; PtPd NPs-decorated multi walled carbon nanotube electrode ; H2O2 estimation ; Amperometric sensor
• 刊名：Biosensors and Bioelectronics
• 出版年：2012
• 期刊代码：12_09565663
• 类别：ch
• 出版时间：15 March, 2012
• 卷：33
• 期：1
• 页码：120-127
• 文件大小：1125 K

摘要

A new highly catalytic and intensely sensitive amperometric sensor based on PtM (where M&#xA0;= Pd, Ir) bimetallic nanoparticles (NPs) for the rapid and accurate estimation of hydrogen peroxide (H₂O₂) by electrooxidation in physiological conditions is reported. PtPd and PtIr NPs-decorated multiwalled carbon nanotube nanocatalysts (PtM/MWCNTs) were prepared by a modified Watanabe method, and were characterized by XRD, TEM, ICP, and XAS. The sensors were constructed by immobilizing PtM/MWCNTs nanocatalysts in a Nafion film on a glassy carbon electrode. Both PtPd/MWCNTs and PtIr/MWCNTs assemblies catalyzed the electrochemical oxidation of H₂O₂. Cyclic voltammetry characterization measurements revealed that both the PtM (M = Pd, Ir)/MWCNTs/GCE possessed similar electrochemical surface areas (鈭?.55 cm²), and electron transfer rate constants (鈭?.23 脳 10^鈭? cm s^鈭?); however, the PtPd sensor showed a better performance in H₂O₂ sensing than did the PtIr counterpart. Explanations were sought from XAS measurements to explain the reasons for differences in sensor activity. When applied to the electrochemical detection of H₂O₂, the PtPd/MWCNTs/GC electrode exhibited a low detection limit of 1.2 渭M with a wide linear range of 2.5-125 渭M (R² = 0.9996). A low working potential (0 V (SCE)), fast amperometric response (<5 s), and high sensitivity (414.8 渭A mM^鈭? cm^鈭?) were achieved at the PtPd/MWCNTs/GC electrode. In addition, the PtPd/MWCNTs nanocatalyst sensor electrode also exhibited excellent reproducibility and stability. Along with these attractive features, the sensor electrode also displayed very high specificity to H₂O₂ with complete elimination of interference from UA, AA, AAP and glucose.