Detection of chymotrypsin using a peptide sensor based on graphene oxide modified with sulfhydryl groups and gold nanoparticles

Abstract

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.