Multilayered catalytic biosensor self-assembled on cyclodextrin-modified surfaces

In this paper we describe the deposition of enzyme layers on cyclodextrin-modified surfaces through self-assembly with adamantane-appended alkaline phosphatase using cyclodextrin-capped gold nanoparticles as supramolecular linkers. The system was studied by surface plasmon resonance and electrochemical methods (cyclic voltammetry, impedance spectroscopy). Up to three enzyme layers were formed on the cyclodextrin coated electrodes and the modified surface was used for the electrochemical detection of heavy metals (Cd²⁺, Ag⁺) based on the inhibition of enzymatic activity by these metal cations.