Mercaptopropionic acid( MPA) was used as the stabilizer,the mono-dispersed Cd S quantum dots( QDs) were synthesized in water. The fluorescence of the Cd S QDs could be effectively quenched by the maltose molecules,and the quenching effect was used to study the absorption behavior of the maltose on the QDs' surface.The result showed that the quenching effect was strongly influenced by the p H value and the QDs concentration,and involved the number of the maltose molecules absorbed on the QDs' surface. The ab...