A strategy for dramatically enhancing the selectivity of molecules showing aggregation-induced emission towards biomacromolecules with the aid of graphene oxide.

By intelligently utilizing the different interacting strengths between different moieties according to the displacement method, general biosensors with aggregation-induced emission (AIE) characteristics for biomacromolecules without selectivity were converted to excellent, highly selective probes for one specific biomacromolecule with the aid of graphene oxide (GO) in an aqueous medium. Importantly, thanks to the different interactions between the AIE molecule and biomacromolecules, just by simply changing the AIE molecule the sensing system could detect different types of biomacromolecules, thereby providing a new approach to the development of AIE-based sensors with high selectivity and sensitivity. More specifically, the complex of A(2)HPS⋅HCl-a derivative of hexaphenylsilone (HPS) functionalized by two amino (A(2)) groups (N(CH(2)CH(3))(3))-and GO only gives an "off-on" response to DNA, with a detection limit of 2.3 μg mL(-1) toward DNA-CT (calf thymus); interestingly, the complex of TPE-N(2)C(4) (1,2-bis{4-[4-(N,N,N-triethylammonium)butoxy]phenyl}-1,2-diphenylethene dibromide) and GO could only detect the presence of bovine serum albumin (BSA), whereas other biomacromolecules, including DNA, RNA, and even other proteins have very little influence.