Engineering proton conductivity in melanin using metal doping.

Long range electrical conduction in biomaterials is an increasingly active area of research, which includes systems such as the conductive pili, proteins, biomacromolecules, biocompatible conductive polymers and their derivatives. One material of particular interest, the human skin pigment melanin, is a long range proton conductor and recently demonstrated as capable of proton-to-electron transduction in a solid-state electrochemical transistor platform. In this work, a novel "doping strategy" is proposed to enhance and control melanin's proton conductivity, potentially enhancing its utility as a transducing material.

The structural impact of water sorption on device-quality melanin thin films.

The melanins are a class of pigmentary bio-macromolecules ubiquitous in the biosphere. They possess an intriguing set of physico-chemical properties and have been shown to exhibit hybrid protonic-electronic electrical conductivity, a feature derived from a process termed chemical self-doping driven by the sorption of water. Although the mechanism underlying the electrical conduction has been established, how the sorbed water interacts with the melanin structure at the physical level has not.

Urease-based ISFET biosensor for arginine determination.

In this work a novel biosensor for arginine determination based on the urease inhibition effect has been proposed. Ion-selective field effect transistors were used as transducers. Urease immobilized in glutaraldehyde vapor served as a biorecognition element of the biosensor.