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Catalytic activity of catalase-silica nanoparticle hybrids: from ensemble to individual entity activity.

ABSTRACT: 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 K_M = 74 mM and a turnover number of k_cat = 8 × 10⁷ s^-1 per NP. The fast turnover number of the hybrid further enabled the electrochemical detection of individual nanoparticle-enzyme hybrid via 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.

SUBMITTER: Chan C

PROVIDER: S-EPMC5363393 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature

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Catalytic activity of catalase-silica nanoparticle hybrids: from ensemble to individual entity activity.

Chan Crystal C Sepunaru Lior L Sokolov Stanislav V SV Kätelhön Enno E Young Neil P NP Compton Richard G RG

Chemical science 20161215 3

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 KM = 74 mM and a turnover number of kcat = ...[more]

PMID: 28451333

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