▎ 摘　　要

In this study, GO modified with sulfhydryl groups was prepared by thiolation on the surface of GO, which makes a relevant material. GO with sulfhydryl groups was combined with gold nanoparticles and then combined with peptide sequence using Au-S bonds. Using the change in absorbance before and after adding chymotrypsin, chymotrypsin was detected. This was label-free detection. The functional peptide EKEKEKEPPPPC was used to optimize the experiment by removing the non-specific adsorption in the system that was the reaction mixture. The detection limit of chymotrypsin was 0.25 pg mL(-1). This can improve the sensitivity of detection. The method can be applied to real samples and has good development and application prospect.