Application of Peptide Self-assembled Multilayers on Detection of Thrombin

Peptide self-assembled multilayers (SAMs) was coated onto the quartz surface. The assembly conditions, such as the assembly agent concentration and assembly time, were examined. The SAMs was characterized via UV-vis absorption spectrometry and scanning electron microscope. Our results showed that the optimal concentration and assembly time for the 3-aminopropyl-triethoxysilane aqueous were 1% (V/V) and 3 h respectively, and those of gold nanoparticles were 2.4 x 10(-4) mol/L and 12 h, respectively, while those of peptide solution were 1 x 10(-4) mol/L and 12 h, respectively. A new sensitive method, based on the theory that peptide could be cleaved at the site of Arg-Gly by thrombin, was established to detect thrombin. In addition, a good linear relationship was obtained in the range from 2.8 x 10(-12) mol/L to 9.9 x 10(-10) mol/L, and the detection limit was 1.4 x 10(-12) mol/L. The peptide self. assembled multilayers were also used in the analysis of blood serum samples, and the recovery rate was within the range from 91.6% to 107.6%.