Long-term stability of a sulfhydryl-Au modification reagent in the biological detection at room temperature

As a good substrate, gold has been widely applied in the fields of biological diagnosis and biological analysis. By forming Au-S bonds, self-assembled molecules could cause monolayer modification on the gold surface and are further connected with different biomolecules via various functional groups such as -OH, COOH, and NH₂. In this work, we conducted a comprehensive study on the properties of previously synthesized trithiamantane and its derivatives. The results indicated that these molecules exhibited better stability than single sulfhydryl-modified molecules in air and aquatic environments. After being placed in room temperature for 30 days, the modified chip with trithiamantane derivatives did not change significantly, while a large amount of single sulfhydryl reagents fell off the modified chips. In addition, gold nanoparticles modified with trithioadamantane were also more stable in aqueous solutions than those modified with single sulfhydryl groups. We carried out corresponding application research on gold nanoparticles modified with probe DNA with the two as terminal modification groups. The stability of gold nanoparticles modified by trithiamantane derivatives after long-term storage was better than that of monosulfhydryl-modified products. Overall, these results indicated a good application prospect of this material.