Chemical Amination of Graphene Oxides and Their Extraordinary Properties in the Detection of Lead Ions

A strategy for the ultra-sensitive detection of Pb(2+) in aqueous media has been developed. The combination of oxidative exfoliation of graphite and subsequent chemical amination resulted in an amine functionalized graphene oxide, which showed ultra-high sensitivity in detecting Pb(2+), as it is an active material in modified anodic stripping voltammetry. A detection limit of as low as 10(-13) M (0.1 pM) has been reached, which is comparable to the result obtained from atomic absorption spectrometry, but is dramatically lower than that from other reported electrochemical analysis methods. This simple and economic approach opens up a new window for the portable, quick, and ultra-sensitive detection of lead ions.