Direct electrochemiluminescence detection of DNA with carbon microelectrodes.

• Research unit: CSEM
• Project number: 2000-04

Key words (English)

electrochemiluminescence, DNA, electrogenerated chemiluminescence, direct ECL, carbon microelectrodes.

Short description (English)

Direct (without TPA) excitation of Ru(bpy)3 2+ electrochemiluminescence in water employs carbon interdigitated microelectrodes (carbon IDA's) for redox cycing of this label. Exploring the ultimate sensitivity limits of this analytical method is the main purpose of this project.

Project aims (English)

The aim of this project is to significantly boost the sensitivity of direct ECL (without TPA) bioanalytical methods through the development of both high efficiency direct ECL excitation and very low noise detection methods

Abstract (English)

Ruthenium chelates are routinely used for the labelling of biomolecules, the detection being based on oxidative-reduction type ECL with a highly reducing coreactant. It had been assumed until recently that redox-cycling type ECL could not take place in aqueous solutions, but required the presence of at least 20% acetonitrile. It has recently (1998) been shown that the ECL reaction of Ru(bpy)3 2+ can be performed in water in a direct way -without any coreactant - with carbon interdigitated microelectrode arrays ( C-IDA), with the advantage of a significantly simpler detection principle for bioassays.

Transfer and application (English)

During the first quarter of this year, a flow injection analysis (FIA) system was set up, along with a photon counting system for optical signal detection, resulting in a sensitivity gain of a factor of 1000 relative to the previously used system.

Patents (English)

WO 98/57154 :Electrochemoluminescent detector.

URL-addresses (English)

www.csem.ch