Chan Crystal, Sepunaru Lior, Sokolov Stanislav V, Kätelhön Enno, Young Neil P, Compton Richard G
Department of Chemistry , Physical & Theoretical Chemistry Laboratory , University of Oxford , South Parks Road , Oxford OX1 3QZ , UK . Email:
Department of Materials , University of Oxford , OX1 3PH , UK.
Chem Sci. 2017 Mar 1;8(3):2303-2308. doi: 10.1039/c6sc04921d. Epub 2016 Dec 15.
We demonstrate the electrochemical detection and characterization of individual nanoparticle-enzyme hybrids. Silica nanoparticles were functionalized with catalase enzyme and investigated spectroscopically and electrochemically. The catalytic activity of the hybrids towards hydrogen peroxide decomposition was comparable to the activity of a freely diffusing enzyme in solution, exhibiting a Michaelis-Menten constant of = 74 mM and a turnover number of = 8 × 10 s per NP. The fast turnover number of the hybrid further enabled the electrochemical detection of individual nanoparticle-enzyme hybrid a novel method: the hydrogen peroxide substrate was generated at a microelectrode which enabled enzymatic activity exclusively within the diffusion layer of the electrode. The method is the first electrochemical approach for measuring hybrid nanoparticles, at the single entity level.
我们展示了单个纳米颗粒-酶杂化物的电化学检测与表征。用过氧化氢酶对二氧化硅纳米颗粒进行功能化处理，并通过光谱学和电化学方法进行研究。这些杂化物对过氧化氢分解的催化活性与溶液中自由扩散的酶的活性相当，米氏常数(K_m = 74 mM)，每个纳米颗粒的周转数(k_{cat}= 8×10^6 s^{-1})。杂化物的快速周转数进一步实现了对单个纳米颗粒-酶杂化物的电化学检测——一种新方法：过氧化氢底物在微电极上产生，这使得酶活性仅在电极的扩散层内发生。该方法是在单个实体水平上测量杂化纳米颗粒的首个电化学方法。
