Homogeneous peptide-based electrogenerated chemiluminescence method for determination of troponin I

International Conference and Exhibition on Biosensors & Bioelectronics

May 14-16, 2012 Embassy Suites Las Vegas, USA

Honglan Qi, Chen Wang, XiaoyingQiu, QiangGao and Chengxiao Zhang

Posters: J Biosens Bioelectron

Abstract :

A novel homogeneous peptide-based electrogeneratedchemiluminescence (ECL)method for determination of troponin I(TnI) was developed by using peptide (FYSHSFHENWPSK) as a molecular recognition element and ruthenium bis(2,2′- bipyridine) (2,2′- bipyridine - 4,4′- dicarboxylic acid) - N- hydroxysuccinimide ester (Ru(bpy)2(dcbpy)NHS) as an ECL label. Ru(bpy)2(dcbpy)NHS was covalently labeled onto peptide through NH2-containing lysine on the peptide via acylation reaction and was utilized as an ECLprobe.In the presence of TnI, a decrease in ECL signal wasobserved upon the binding event between peptide and target TnI. The reason of the decrease in ECL intensity was studied by electrochemical method and attributed to the change ofdiffusion coefficient induced by binding event. The ECL intensity versus the concentration ofTnI was linear in the range from 7.8×10-10 g/mL to 7.8×10-8 g/mL with a detection limit of 1.2×10-10g/mL.The relative standard derivation for 2.6×10-9 g/mL was 3.8%. The proposedmethod has been applied to assay TnI in human control serum with satisfactory results.This work demonstrates that the combination of smallpeptide with a highlysensitive ECL technique for peptide-based homogeneous ECL bioassay is a great promising approach for sensitive and selectivedetermination of protein.