Spectroscopic detection of thrombin with peptides self-assembled on gold nanoparticles hybridized graphene oxide

Thrombin is an important kind of proteases that can cleavage specific peptide bonds and plays a crucial role in numerous diseases, which leads to large amounts of efforts on its detection. In this study, a novel peptide self-assembled biosensor was developed based on gold nanoparticles functionalized graphene oxide (GO) for specific detection of thrombin. Through sulfhydryl design, peptides containing thrombin cleavage sites could self-assemble with the nanocomposites of the graphene material and gold particles, which brought the biosensor unique optoelectronic properties and high biological sensitivity to transduce bio-molecular interactions into optical signals. Spectroscopic measurements were carried out in the presence of thrombin to observe an increase of the absorption peak at ∼528 nm and a decrease of the absorbance at wavelength larger than 600 nm. The biosensor showed a linear dose-dependence and stable response to thrombin. And with a 528-680 nm absorbance ratio as the sensitive detection parameter, the self-assembled biosensor exhibited high sensitivity and specificity for the thrombin detection. Thus, it revealed convenient and sensitive detection abilities for protease of thrombin, indicating a promising prospect for other related proteases, such as matrix metalloproteinases to cancer related diseases.