A simple and sensitive electrogenerated chemiluminescence biosensor was developed to monitor matrix metalloproteinase 2 (MMP-2) by employing a specific peptide (CGPLGVRGK) as a molecular recognition substrate. Bis(2,2′-bipyridine)-4′-methyl-4-carboxybipyridine-ruthenium N -succinimidyl ester-bis(hexafluorophosphate) (Ru(bpy) 2 (mcbpy-O-Su-ester)(PF 6 ) 2 (Ru1) was used as ECL-emitting species and covalently labeled onto the peptide through NH 2 -containing lysine on the peptide via acylation reaction to form Ru1-peptide as an ECL probe. An ECL peptide-based biosensor was fabricated by self-assembling the ECL probe onto the surface of gold electrode. MMP-2 can specifically cleave the Ru1-peptide on the electrode surface, which led the partly Ru1-peptide to leave the electrode surface and resulted in the decrease of the ECL intensity obtained from the resulted electrode in 0.1 M phosphate-buffered saline (pH 7.4) containing tri- n -propylamine. The decreased ECL intensity was piecewise linear to the concentration of MMP-2 in the range from 1 to 500 ng/mL. Moreover, the ECL biosensor is successfully applied to detection of MMP-2 secreted by living cell, such as HeLa cells. Additionally, the biosensor was also applied to the evaluation of matrix metalloproteinase inhibitors. The strategy presented here is promising for other disease-related matrix metalloproteinase assay and matrix metalloproteinase inhibitor profiling with sensitivity and simplicity.
Detection of MMP-2 released from living cells by ECL peptide-based biosensor
It is a great challenge to detect the target selectively and accurately in complex biological samples. A ratiometric signal amplification strategy based on antifouling peptide is proposed to detect thrombin (TB) in this work. The electrode is modified with conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and [email protected] Then the bi-functional peptide anchors to the modified electrode and captures the low toxic electrochemiluminescence (ECL) probe. The bi-functional peptide includes a new antifouling sequence (DRDRDRDR) and a TB recognizable sequence (SGRPVLG), while the former can greatly reduce the non-specific adsorption in complex samples and the latter can be cleaved by TB. The new self-enhanced luminescence probe labeled as PAMAM-QDs is composed of low toxic and water-soluble CuInZnS/ZnS quantum dots (CIZS/ZnS QDs) and polyamidoamine (PAMAM) via amide bonds. Concentration of TB can be obtained via the ratio of the signals of ECL QDs /ECL [email protected] accurately and sensitively. The ECL biosensor with the detection line 1.82 fM can work from 10 fM to 1 nM. Thanks to the antifouling property of the designed peptide and the amplification of the new ECL probe, the biosensor can be used for quantifying TB in practical complex samples with high selectivity and sensitivity.
危险品化学品经营许可证（带存储）