Scodeller P, Flexer V, Szamocki R, Calvo E J, Tognalli N, Troiani H, Fainstein A
INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
J Am Chem Soc. 2008 Sep 24;130(38):12690-7. doi: 10.1021/ja802318f. Epub 2008 Sep 3.
We report a fully integrated core-shell nanoparticle system responsive to glucose. The system is comprised of self-assembled glucose oxidase and an osmium molecular wire on core-shell Au nanoparticles. Characterization of the functional nanoparticles by spectroscopy, quartz crystal microbalance and electrochemical techniques has shown that the catalytically active shell has a structure as designed and all components are active in the self-assembled multilayer shell. Furthermore, amperometric reagentless detection of glucose and contactless photonic biosensing by the Os(II) resonant Raman signal have been demonstrated. The enzymatic reduction of FAD by glucose and further reduction of the Raman silent Os(III) by FADH 2 yields a characteristic enzyme-substrate calibration curve in the millimolar range. Furthermore, coupling of electronic resonant Raman of the osmium complex with the SERS amplification by Au NPs plasmon resonance has been demonstrated which leads to an extra enhancement of the biosensor signal. We present a proof of concept extending the work done with planar surfaces to core-shell NPs as an advance in the design of glucose-responsive chemistry detected by SERS-like methods.
我们报道了一种对葡萄糖有响应的完全集成的核壳纳米颗粒系统。该系统由自组装的葡萄糖氧化酶和核壳金纳米颗粒上的锇分子线组成。通过光谱学、石英晶体微天平及电化学技术对功能性纳米颗粒进行表征，结果表明，具有催化活性的壳层具有设计的结构，且所有组分在自组装多层壳层中均具有活性。此外，还展示了通过Os(II)共振拉曼信号对葡萄糖进行无试剂安培检测以及非接触式光子生物传感。葡萄糖对FAD的酶促还原以及FADH₂对拉曼沉默的Os(III)的进一步还原，在毫摩尔范围内产生了特征性的酶-底物校准曲线。此外，还证明了锇配合物的电子共振拉曼与金纳米颗粒等离子体共振的表面增强拉曼散射（SERS）放大作用的耦合，这导致生物传感器信号进一步增强。我们展示了一个概念验证，即将在平面表面上所做的工作扩展到核壳纳米颗粒，这是通过类似SERS方法检测葡萄糖响应化学设计方面的一项进展。
