Electrochemical Adsorption Technique for Immobilization of Single-Stranded Oligonucleotides onto Carbon Screen-Printed Electrodes

Abstract

The data reported in literature demonstrate that screen-printed carbon electrodes are very suitable for supporting nucleic-acid layers and to transduce effectively the DNA recognition event and many works have been devoted to developing self contained screen-printed DNA chips. In an effort to develop a rapid and efficient scheme for immobilizing nucleic acids onto carbon screen-printed transducers, many authors took advantage of the strong adsorptive accumulation of these biomolecules at the screen-printed carbon surfaces. In particular, many of them reported that electrochemical adsorption (adsorption controlled by a positive potential) enhances the stability of the probe and this technique was preferentially chosen. Thus, this review will focus on an electrochemical genosensor developed using carbon screen-printed electrodes as the transducers; the methods to immobilize DNA probes onto carbon based surfaces will be reviewed and special emphasis will be given to the description of the electrochemical adsorptive accumulation. The different strategies to perform the measurement are illustrated. Examples are given of the application of screen-printed DNA biosensors in the field of clinical as well as environmental and food analysis.