Detection of biomolecules via benign surface modification of graphene

Abstract

The modification of single layer graphene by assembly of a biotin moiety that is functionalized with a diazonium salt and the subsequent detection of Streptavidin (SA) upon exposure of graphene to compound V was highlighted. Graphene was prepared via CVD using a copper foil annealed at 975°C in 6 sccm forming gas at a pressure of 500 mTorr for 10 min, followed by flowing ethylene for 10 min at the same temperature. The Raman spectra of single-layer graphene has three key characteristic peaks, the G peak, which his due to the vibrational mode of sp2 bonded carbon, a 2D peak, and the D band, which is induced by defects in the structure. Upon washing with PBS, there is no change in the reflectivity signal due to the high affinity between Biotin and the SA. Scanning electron microscopy (SEM) imaging was used to determine the concentration dependence on SA binding.