Characterization of an electrochemical sensor for the determination of insulin prepared by colloidal lithography

This work is focused on the characterization of the surface of an electrochemical sensor modified by nickel cavities prepared by the method of colloidal lithography, which will ensure significantly higher surface homogeneity and reproducibility compared to the use of nickel nanoparticles. The electrochemical sensor was prepared by depositing Ni film into an interglomerate space of colloid mask, which formed Ni cavities with a diameter of ∼500 nm after dissolving the PS. The electrode surface was characterized by SEM and AFM. The diameter of the prepared cavities was approximately 500 nm and the depth calculated from AFM was 190 ± 4 nm and from SEM 188 nm. Based on the characterization of the surface of the prepared sensor and the calculation of the electrochemical area, conductive glass modified with nickel nanocavities represents a suitable candidate for electrochemical detection of insulin. (authors)