With the prevalence of diabetes, rapid and simple blood glucose monitoring has become more and more important. Here, we report the synthesis of bio-templated N3-CdZnTeS quantum dots (QDs), which are great fluorescent biological labels and were used for the fabrication of dual-emissive dye@protein-QD conjugates via copper-free click chemistry, such as the 5(6)-carboxyfluorescein@glucose oxidase-quantum dot (FAM@GOx-QDs) complex. When adding glucose, the red fluorescence of the CdZnTeS QDs sharply decreased, while the green fluorescence of FAM was invariable. A good linear relationship ranging from 0.3 to 30 μM was obtained for glucose detection, with the limit of detection as low as 0.035 μM. Notably, the DNA-bridging FAM@GOx-QDs complex exhibited enhanced enzyme activity and stability, and was applied for the differentiation of diabetic and healthy people by the naked eye.