Electrochemical Biosensor Utilizing Supramolecular Association of Enzyme on Sol−gel Matrix Embedded Gold Nanoparticles Supported Reduced Graphene Oxide−cyclodextrin Nanocomposite

Herein we present β‐cyclodextrin (CD)‐functionalized reduced graphene oxide (RGO) nanosheets supported on silicate sol‐gel matrix‐embedded gold nanoparticles (Au NPs) modified electrode as a new affinity binding nanocomposite. The modified electrode is fabricated through layer‐by‐layer drop casting followed by immobilization of chemically modified enzyme conjugate (horse radish peroxidase (HRP)−adamantane carboxylic acid (ADA)). This affinity system is based on the supramolecular association between CDs and HRP−ADA and is mimicking the biological avidin−biotin interactions. CDs‐functionalized RGO (RGO−CD) functions as a macrocyclic host to form stable supramolecular inclusion complexes with enzyme conjugate. Besides Au NPs improve the interfacial interaction with RGO−CD nanosheets, and thus exhibit synergistic electrocatalytic effect toward H 2 O 2 reduction in the presence of 1 mM hydroquinone.