Highly selective electrogenerated chemiluminescence biosensor for simultaneous detection of matrix metalloproteinase-2 and matrix metalloproteinase-7 in cell secretions

Abstract Highly selective bioassays are extremely important in biological and chemical sensing. Herein, a selective biosensor incorporating sensitive electrogenerated chemiluminescence (ECL) is reported for simultaneous detection of two matrix metalloproteinases (MMPs) that are related to pathological development and progression of cancer. An Ir complex ((dfppy) 2 Ir(dcbpy)PF 6 , Ir1) and a Ru complex ((Ru(bpy) 2 (mcbpy-O-Su-ester)(PF 6 ) 2 , Ru1) were employed as potential resolved ECL labels. It was found that the Ru1 and Ir1 in the presence of tripropylamine could produce two well-separated strong ECL emissions at +0.9 V and +1.4 V vs Ag/AgCl, respectively, with a large difference of ECL peak potential (∼0.5 V) at the gold electrode, which provided an access for potential-resolved detection of dual targets. A multiplexed biosensor was simply fabricated by co-immobilizing the Ir1 and Ru1 labeled peptides on a gold electrode via self-assembling technique. It was facile to determine MMP-2 and MMP-7 in a single run with detection limit as low as 5 ng/mL and 10 pg/mL, respectively. The advantages of the multiplexed ECL biosensor were further exemplified by analyzing two MMPs released from living HeLa, K562, HCT116 and macrophage cells. The multiplexity of the biosensor will open a new door for facile and rapid detection of multiple biomarkers.