▎ 摘　　要

Gold-coated graphene oxide hybrid material (GO/AuNPs) has exceptional physical and chemical properties like pi-pi stacking interaction and plays a role in quencher of fluorescence dye. Therefore, GO/AuNPs could enhance the signal-to-background ratio with fluorescence dye that was the point in this fluorescent biosensor. In this study, tetramethy1-6-carboxy-rhodamine (TAMRA)-labeled aptamers that specifically interact with the hyaluronic acid binding domain of CD44 were used as targets to investigate the applicability of the method. GO/AuNPs TAMRA-aptamer complexes could detect CD44 target cancer cells within a concentration range of 1 x 10(1) to 1 x 10(7) CFU/mL. A linear relationship was observed between target cell concentration and relative fluorescence intensity. The more mounted up CD44 target cell concentrations, relative fluorescence intensity of GO/AuNPs TAMRA-aptamer complexes was increased even more, which was superior to that of GO alone. Sensitivity of the detection system displayed a low detection limit of 1 x 10(1) CFU/mL. Additionally, this method is specific in that fluorescence is not much enhanced in CD44 negative cancer cell line. Thus, the fluorescence sensing based on GO/AuNPs could be developed to receptive and robust detection tool for various target molecules. (C) 2015 Elsevier B.V. All rights reserved.