On-Site Rapid Detection of Ethidium Bromide Using Ultramicroelectrode Sensors

Ethidium bromide (EtBr) is one of the most used non-protein molecules in molecular biology, specifically for fluorescence-based detection of nucleic acids during gel electrophoresis. ETBr2 fluoresces when exposed to ultraviolet light, intensifying after binding to DNA. Although non-radioactive, the ability of EtBr to bind preferentially to the double strand structure and to enter the nucleus membrane of cells makes it a toxic substance, which can cause tumorigenesis due to the genetic damage induced by its interaction. Its reputation as a potential mutagen has created a need to minimize its use and eliminate the risks associated with exposure, as well as the potential environmental hazards associated with disposal. In the last 10 years, EtBr has also been shown to be electrochemically active. In this work, we show the modification of an ultra-micro electrode sensor and subsequent detection of EtBr from Phosphate buffer on a nanomolar level (LoD of 12 nM). The sensor can detect concentrations with a higher sensitivity and reliability than the classic UV lamp in a practical manner. This novel sensor may offer a potential solution to test for and reduce potentials risks associated with both job related risk and unwanted environmental release of EtBr.