A novel benzene sulfonamide-appended silica precursor has been designed and it played dual roles. Firstly, typical green emissions derived from f–f transitions have been achieved through its complexation with terbium ions. Secondly, the hydrolysis–polycondensation process that leads to new organic–inorganic hybrid material has been realized by its reactive trimethoxysilane unit. Different microstructures, controllable synthesis, and their photophysical properties were investigated. Importantly, these novel nanosystems were demonstrated to be capable of monitoring Cu2+ in terms of sharp luminescence changes. A novel benzene sulfonamide-appended silica precursor has been designed, and typical green emissions derived from f–f transitions have been achieved. The hydrolysis–polycondensation process that leads to new organic–inorganic hybrid material has been realized by its reactive trimethoxysilane unit. Importantly, these novel nanosystems were demonstrated to be capable of monitoring Cu2+ in terms of sharp luminescence changes.