Protein-based nanobiosensor for direct detection of hydrogen sulfide

¹ Faculty of New Science and Technology, University of Tehran - Tehran, Iran
² Department of Biotechnology and Pharmaceutical Engineering, Faculty of Chemical Engineering, School of Engineering, University of Tehran - Tehran, Iran
³ Research Center for New Technologies in Life-Science Engineering, University of Tehran - Tehran, Iran
⁴ School of Biology, College of Science, University of Tehran - Tehran, Iran

^(a) amoabdiny@ut.ac.ir

Received: 2 September 2014
Accepted: 19 December 2014

Abstract

The chemically modified cytochrome c from equine heart, EC (232-700-9), was immobilized onto gold nanoparticles in order to develop a specific biosensing system for monitoring hydrogen sulfide down to the micromolar level, by means of a localized surface plasmon resonance spectroscopy. The sensing mechanism is based on the cytochrome-c conformational changes in the presence of H₂S which alter the dielectric properties of the gold nanoparticles and the surface plasmon resonance peak undergoes a redshift. According to the experiments, it is revealed that H₂S can be detected at a concentration of $4.0\ \mu \text{M}\ (1.3\ \text{ppb})$ by the fabricated biosensor. This simple, quantitative and sensitive sensing platform provides a rapid and convenient detection for H₂S at concentrations far below the hazardous limit.