Electrochemical impedance spectroscopy for quantization of matrix Metalloproteinase-14 based on peptides inhibiting...

We reported here two novel electrochemical impedance spectroscopy biosensors were developed for the first time for highly sensitive quantification of matrix metalloproteinase-14 (MMP-14) based on binding interaction between hemopexin-like domain (PEX) of MMP-14 (PEX-14) and its inhibitory peptides. Specific inhibitory peptides (IVSC or ISC) inhibiting homodimerization or heterodimerization of MMP-14 was first self assembled on the surface of gold electrode and blocked with 6-mercapto-1-hexanol on a gold electrode surface used as IVSC or ISC modified biosensor, respectively. IVSC modified biosensor can be used for detection of MMP-14 by using the direct IVSC-MMP-14 interaction inhibiting MMP-14 homodimerization as well as ISC modified biosensor for indirect detection of MMP-14 via PEX-14 mediated peptide-MMP-14 binding. The electron transfer resistance (R_et) of biosensor was monitored to measure MMP-14 using Fe(CN)₆^3-/4- as probe. The increase of the R_et of the biosensors are linear with the concentration of MMP-14 in the range from 1 μg L^-1 to 10 μg L^-1 with detection limit of 0.19 μg L^-1 for IVSC modified biosensor and 0.1 ng L^-1 to 50 ng L^-1 with detection limit of 7 ng L^-1 for ISC modified biosensor. This work demonstrates that probing the interaction between peptide inhibitor and PEX of MMPs represents a novel approach to assess MMPs-mediated cancer dissemination.