A sensor for glycoproteins based on dendritic gold nanoparticles electrodeposited on a gold electrode and modified with a phenylboronic acid

We describe a gold electrode capable of recognizing glycoproteins (as exemplified for the model protein horseradish peroxidase; HRP). It is based on the interaction between the cis-diol groups of the glycoprotein and the boronate groups of 4-mercaptophenylboronic acid (MPBA) that was self-assembled on dendritic gold nanoparticles electrodeposition on the surface of a gold electrode. The modified electrode exhibits linear electrochemical response to HRP in the 2.5 nM to 25 μM concentration range. The detection limit is 0.5 nM at a signal-to-noise ratio of 3.