Preparation of ultrafine CdS in an aqueous solution: Surface modification with a carboxylgroup for using a fluorescent probe

Nano-sized semiconductor CdS covered with a carboxyl group was prepared in an aqueous solution and demonstrated to be applicable as a fluorescent prob e. Amino-modified latex beads or those mixed with CdS without surface modif ication could not detect any luminescence. On the other hand, those attache d to the CdS with carboxyl group were distinct the fluorescent images. It s uggests that the carboxyl group capped CdS particle can be used as a fluore scent probe.