Method for manufacturing gold nanoelectrodes for nitrite ion detection via co-deposition with viruses

Highly Selective Nitrite Ion Sensor Electrode Using M13 Virus-Gold Co-deposited Nanostructures

This technology involves manufacturing an electrode for nitrite ion detection by electrochemically co-depositing M13 viruses, engineered to express four glutamic acid (EEEE) peptides on their surface, with a gold precursor onto an ITO electrode to form dendritic gold nanostructures. The virus acts as a template without the need for surfactants.

Nitrite ions, which enter water sources through fertilizers and food additives, can contaminate water and form carcinogenic N-nitrosamines, necessitating precise measurement. However, conventional methods like spectrophotometry and chromatography require expensive equipment and long analysis times, while electrochemical sensors have faced limitations in easily creating electrode structures with high sensitivity and selectivity.

This technology uses virus surface peptides to capture gold ions and control reduction sites, obtaining a high-surface-area nanocomposite through a single-step electrodeposition. The resulting electrode shows higher oxidation current than reference electrodes, reacts selectively to nitrite ions even among various interfering substances, and detects concentrations as low as 100μM. Applicable to portable sensors for drinking water monitoring, agricultural runoff, and food safety, it enables rapid on-site contamination assessment without expensive equipment.

‍

‍

Key Features:

• Preparing an electrolyte containing the gold precursor HAuCl4, M13 viruses expressing EEEE sequence peptides on their surface, and sulfuric acid
• Immersing an ITO electrode in the electrolyte and applying potential to electrochemically co-deposit gold nanostructures onto the electrode surface
• A configuration where the gold precursor attaches to the amine groups of the glutamic acid on the virus surface, reduces to gold, and the carboxyl groups attach to the ITO surface to form a dendritic nanocomposite
• A method for manufacturing a gold nanoelectrode for nitrite ion detection using a virus engineered to attach peptides to the surface of the P8 protein, the main coat protein of the M13 virus

‍