Supramolecular assembly of perylene derivatives on Au functionalized graphene for sensitivity enhancement of electrochemiluminescent immunosensor

A novel electrochemiluminescent immunosensor was designed for cancer biomarker detection based on peroxydisulfate cathodic electrochemiluminescence using a new enhancer, one kind of perylene derivatives, synthesized by integrating the arginine covalently onto the 3,4,9,10-perylenetetracarboxylic acid (PTCA) (abbreviation as PTC-Arg). Combining the supramolecular assembly method, the aromatic compound of PTC-Arg was effectively immobilized on the gold nanoparticles functionalized graphene (Au@Gra) by pi-pi stacking (PTC-Arg/Au@Gra). And then PTC-Arg/Au@Gra complexes were further used as multifunctional nanocarriers for the absorption of the second antibody of alpha-fetoprotein (Ab(2)), which formed sandwich-type immunoassay format through associating with alpha-fetoprotein (AFP) and the first antibody (Ab(1)). With PTC-Arg/Au@Gra as enhancer of peroxydisulfate system, the immunosensor exhibited a wide dynamic range of 0.001-10 ng mL(-1) and detection of limits (LODs) of 0.3 pg mL(-1), respectively. It also suggested a great potential development and applications for sensitive bioassays in clinical detection. (C) 2013 Elsevier B.V. All rights reserved.