Aptasensor based on the selective electrodeposition of protein-linked gold nanoparticles on screen-printed electrodes

The electrodeposition of DNA-gold nanoparticles previously developed in our group has been used as starting point for the electrodeposition of proteins attached to gold nanoparticles. We have performed a proof of principle by developing a methodology based on the electrodeposition of proteins bound to gold nanoparticles on screen-printed gold microelectrodes using, in a first approach, horseradish peroxide-conjugated gold nanoparticles (gold-HRP). The electrodeposition was achieved at a current positive potential of 800 mV vs. Ag/AgCl and the functionality of the electrodeposited HRP-particles was tested by electrochemical reduction of H2O2. Furthermore, we used this proof of concept in an aptasensor application to detect Leishmania infantum KMP-11. Hence, we have demonstrated not only the functionality of the electrodeposition of proteins bound to gold nanoparticles, but also the utility of the method with the aim of developing a real biosensor containing multiple enzymes or proteins in a multimodular device.