Facile Synthesis of Prussian Blue-Filled Multiwalled Carbon Nanotubes Nanocomposites: Exploring Filling/Electrochemistry/Mass-Transfer in Nanochannels and Cooperative Biosensing Mode

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• 作者：Ting Wang ; Yingchun Fu ; Lijuan Bu ; Cong Qin ; Yue Meng ; Chao Chen ; Ming Ma ; Qingji Xie ; Shouzhuo Yao
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：October 4, 2012
• 年：2012
• 卷：116
• 期：39
• 页码：20908-20917
• 全文大小：492K
• 年卷期：v.116,no.39(October 4, 2012)
• ISSN：1932-7455

文摘

We report on mild and selective filling of multiwalled carbon nanotubes (MWCNTs) with Prussian blue (PB) to explore the filling/electrochemistry/mass-transfer in nanochannels and the biosensing mode of nanochannel interior-exterior cooperation. PB-filled MWCNTs (MWCNTs-PB_in) are prepared by filling MWCNTs with the gradually growing PB and then selectively removing the outer-surface PB by careful chemical washing. The prepared MWCNTs-PB_in composites possess high filling yield (mass ratio of PB to MWCNTs, (30 卤 3)%) and electroactivity percentage (mass ratio of electroactive PB to total PB, (45 卤 3)%). The MWCNTs-PB_in composites on Au electrode exhibit strong and stable electrocatalytic activity of filled PB for H₂O₂ reduction and electroanalysis. The filling of the MWCNTs with electroactive PB also provides a new experimental platform to deal with the widely concerned issue of mass transfer inside nanochannels. The normalized cyclic voltammetric responses of filled PB on MWCNTs-PB_in electrode at relatively low scan rates (below 125 and 75 mV s^鈥? for mass transfer of K⁺ and K⁺ + H₂O₂, respectively) were found to be equivalent to those of conventionally electrodeposited PB on MWCNTs/Au and Au electrodes, demonstrating that the mass transfer of K⁺ and H₂O₂ inside our MWCNTs is comparable to those outside our MWCNTs at the low scan rates. Furthermore, the unoccupied outer surfaces of MWCNTs-PB_in are conveniently exploited to bind 4-(1-pyrenyl) butyric acid through 蟺鈥撓€ stacking interaction and then to anchor glucose oxidase or lactate oxidase through the EDC/NHS chemistry. Thus, we have developed a novel cooperative biosensing mode by combining outer-surface biocatalyzed oxidation of substrate with interior PB-catalyzed reduction of enzymatically generated H₂O₂, which endows our biosensors with low detection potential (鈭?.1 V) and satisfactory sensitivity/selectivity.