Proteolytic disassembly of peptide-mediated graphene oxide assemblies for turn-on fluorescence sensing of proteases.
Molecule-induced assembly of nanomaterials can alter their unique chemical and physical properties, which can be a promising approach for sensing. Herein, we demonstrate an optical 'turn-on' biosensor for the detection of matrix metalloproteinase-2 (MMP-2), fabricated by means of a peptide-induced assembly of fluorescent graphene oxide (GO). Functionalization of GO with a peptide substrate for MMP-2 bearing a thiol group leads to its self-assembly via disulfide bonding, accompanied by self-quenching of GO's strong fluorescence. This peptide-induced GO assembly is then disassembled by proteolytic cleavage in the presence of MMP-2, thereby restoring the level of self-quenched GO fluorescence. With this approach, we are able to detect MMP-2 and to investigate the kinetic parameters of MMP-2 activity. The GO-peptide assembly is successfully applied to the selective and sensitive detection of MMP-2 secreted by living cells, human hepatocytes HepG2, at a concentration of 2 ng mL(-1).
School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Republic of Korea. yslee@snu.ac.kr.
Jin-Kyoung
JK
Yang
Department of Chemical Engineering, Hanyang University, Ansan 426-791, Republic of Korea. kjh75@hanyang.ac.kr.
Seon-Yeong
SY
Kwak
Department of Chemical Engineering, Hanyang University, Ansan 426-791, Republic of Korea. kjh75@hanyang.ac.kr.
Su-Ji
SJ
Jeon
School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Republic of Korea. yslee@snu.ac.kr.
Eunjin
E
Lee
Department of Chemical Engineering, Hanyang University, Ansan 426-791, Republic of Korea. kjh75@hanyang.ac.kr.
Jong-Min
JM
Ju
Department of Chemical Engineering, Hanyang University, Ansan 426-791, Republic of Korea. kjh75@hanyang.ac.kr.
Hye-In
HI
Kim
School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Republic of Korea. yslee@snu.ac.kr.
Yoon-Sik
YS
Lee
Department of Chemical Engineering, Hanyang University, Ansan 426-791, Republic of Korea. kjh75@hanyang.ac.kr.
Jong-Ho
JH
Kim
D005453:Fluorescence; D006108:Graphite; D056945:Hep G2 Cells; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D010087:Oxides; D010447:Peptide Hydrolases / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*
D010087:Oxides; D010455:Peptides; D006108:Graphite; D010447:Peptide Hydrolases; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2