Enzymatic Growth of Quantum Dots: Applications to Probe Glucose Oxidase and Horseradish Peroxidase and Sense Glucose

Authors

  • Laura Saa,

    1. CIC biomaGUNE, Parque Tecnológico de San Sebastián, Paseo Miramón 182, 20009, San Sebastián, Spain, Tel. +34943005308; Fax +34943005314
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  • Valeri Pavlov

    Corresponding author
    1. CIC biomaGUNE, Parque Tecnológico de San Sebastián, Paseo Miramón 182, 20009, San Sebastián, Spain, Tel. +34943005308; Fax +34943005314
    • CIC biomaGUNE, Parque Tecnológico de San Sebastián, Paseo Miramón 182, 20009, San Sebastián, Spain, Tel. +34943005308; Fax +34943005314.
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Abstract

Three innovative assays are developed for the detection of enzymatic activities of glucose oxidase (GOx) and horseradish peroxidase (HRP) by the generation of CdS quantum dots (QDs) in situ using non-conventional enzymatic reactions. In the first assay, GOx catalyzes the oxidation of 1-thio-β-D-glucose to give 1-thio-β-D-gluconic acid. The latter is spontaneously hydrolyzed to β-D-gluconic acid and H2S, which in the presence of cadmium nitrate yields fluorescent CdS nanoparticles. In the second assay HRP catalyzes the oxidation of sodium thiosulfate with hydrogen peroxide generating H2S and consequently CdS QDs. The combination of GOx with HRP, allowed quantification of glucose in plasma by following growth of fluorescent QDs.

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