A label-free and homogenous electrochemical assay for matrix metalloproteinase 2 activity monitoring in complex samples based on electrodes modified with orderly distributed mesoporous silica films

Abstract

Herein, a label-free and homogeneous electrochemical strategy for monitoring of matrix metalloproteinase 2 (MMP-2) activity was proposed based on electrodes modified with orderly distributed mesoporous silica films (MSFs). In the absence of target MMP-2, an artificially substrate peptide with positive charge was absorbed on the surface of MSFs by electrostatic interaction, which could prevent electrochemical molecules [Ru(NH3)6]Cl3 from approaching the electrode surface. When the substrate peptide was hydrolyzed by target MMP-2, [Ru(NH3)6]Cl3 could arrive to the electrode surface and lead to the increase of electrochemical signal. This assay showed considerable sensitivity to target MMP-2, which could measure it down to 0.98 ng. mL−1. Meanwhile, a satisfied response to the inhibitor of MMP-2 was also achieved (IC-50 value = 1.68 μM). Significantly, it displayed satisfactory performances in the complicated biological samples including cell lysates and human serum. Taking advantages of the anti-fouling ability in biological complex samples of MSFs and the high efficiency of homogeneous sensing, this assay realized the electrochemical detection of MMP-2 with accuracy and sensitivity, which exhibited significant potential in clinical biomedicine and biological analysis of cancer-related protease.