Wang Ting, Fu Yingchun, Chai Liyuan, Chao Long, Bu Lijuan, Meng Yue, Chen Chao, Ma Ming, Xie Qingji, Yao Shouzhuo
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081 (P.R. China), Fax: (+86) 731-88872046; School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (P.R. China).
Chemistry. 2014 Feb 24;20(9):2623-30. doi: 10.1002/chem.201304035. Epub 2014 Jan 30.
Facile filling of multiwalled carbon nanotubes (MWCNTs) with Prussian blue nanoparticles (PBNPs) of high peroxidase-like catalytic activity was performed to develop novel colorimetric sensing protocols for assaying H2O2 and glucose. Fine control of PBNP growth was achieved by modulating the concentration ratio of K3 [Fe(CN)6] and FeSO4 precursors in an acidic solution containing ultrasonically dispersed MWCNTs, and thus size-matched PBNPs could be robustly immobilized in the cavities of the MWCNTs (MWCNT-PBin). Unlike other reported methods involving complicated procedures and rigorous preparation/separation conditions, this mild one-pot filling method has advantages of easy isolation of final products by centrifugation, good retention of the pristine outer surface of the MWCNT shell, and satisfactory filling yield of (24±2) %. In particular, encapsulation of PBNPs of poor dispersibility and limited functionality in dispersible and multifunctional MWCNT shells creates new and valuable opportunities for quasihomogeneous-phase applications of PB in liquid solutions. The MWCNT-PBin nanocomposites were exploited as a peroxidase mimic for the colorimetric assay of H2O2 in solution by using 3,3',5,5'-tetramethylbenzidine (TMB) as reporter, and they gave a linear absorbance response from 1 μM to 1.5 mM with a limit of detection (LOD) of 100 nM. Moreover, glucose oxidase (GOx) was anchored on the outer surface of MWCNT-PBin to form GOx/MWCNT-PBin bionanocomposites. The cooperation of outer-surface biocatalysis with peroxidase-like catalysis of interior PB resulted in a novel cooperative colorimetric biosensing mode for glucose assay. The use of GOx/MWCNT-PBin for colorimetric biosensing of glucose gave a linear absorbance response from 1 μM to 1.0 mM and an LOD of 200 nM. The presented protocols may be extended to other multifunctional nanocomposite systems for broad applications in catalysis and biotechnology.
通过用具有高类过氧化物酶催化活性的普鲁士蓝纳米颗粒（PBNP）轻松填充多壁碳纳米管（MWCNT），开发了用于检测H2O2和葡萄糖的新型比色传感方案。在含有超声分散的MWCNT的酸性溶液中，通过调节K3[Fe(CN)6]和FeSO4前体的浓度比，实现了对PBNP生长的精细控制，因此尺寸匹配的PBNP可以牢固地固定在MWCNT的腔内（MWCNT-PBin）。与其他涉及复杂程序和严格制备/分离条件的报道方法不同，这种温和的一锅法填充方法具有通过离心轻松分离最终产物、MWCNT壳原始外表面保留良好以及填充产率令人满意（24±2）%的优点。特别是，将分散性差且功能有限的PBNP封装在可分散且多功能的MWCNT壳中，为PB在液体溶液中的准均相应用创造了新的宝贵机会。MWCNT-PBin纳米复合材料被用作过氧化物酶模拟物，通过使用3,3',5,5'-四甲基联苯胺（TMB）作为报告分子对溶液中的H2O2进行比色测定，它们给出了从1 μM到1.5 mM的线性吸光度响应，检测限（LOD）为100 nM。此外，葡萄糖氧化酶（GOx）被锚定在MWCNT-PBin的外表面，形成GOx/MWCNT-PBin生物纳米复合材料。外表面生物催化与内部PB的类过氧化物酶催化的协同作用导致了一种用于葡萄糖测定的新型协同比色生物传感模式。使用GOx/MWCNT-PBin进行葡萄糖的比色生物传感给出了从1 μM到1.0 mM的线性吸光度响应，LOD为200 nM。所提出的方案可能扩展到其他多功能纳米复合系统，以在催化和生物技术中广泛应用。
