Electrochemical albumin sensing based on silicon nanowires modified by gold nanoparticles

Si nanowires (SiNWs) were modified by Au nanoparticles (AuNPs) using a self-assembled monolayer of aminopropyltriethoxysilane (APTES) and used for direct sensing of the bovine serum albumin (BSA). It was shown that repeated thermal treatment of the sensor greatly enhanced the reliability of the SiNW sensor by increasing the electrical conductivity largely from carbonization of the APTES molecules and from bringing the AuNPs in intimate contact with the SiNW surface. The AuNP-modified SiNW array sensor was able to detect 1-7 μM of BSA. The sensor exhibited a good sensitivity over the tested concentration range and linear behavior. It is expected that the proposed label-free biosensor can be further developed to selectively detect and quantify biomolecules other than BSA.

Graphical abstractSi nanowire array was modified by Au nanoparticles using a self-assembled monolayer of aminopropyltriethoxysilane (APTES) and used for direct sensing of the bovine serum albumin. It was shown that repeated thermal treatment of the sensor greatly enhanced the reliability by increasing the electrical conductivity largely from carbonization of the APTES molecules and from bringing the Au nanoparticles in intimate contact with the nanowire surface.Download full-size imageResearch highlights▶ Si nanowire array was modified by Au nanoparticles using a self-assembled monolayer. ▶ The modified Si nanowire array was used to detect bovine serum albumin. ▶ Repeated thermal annealing improved the reliability of the Si nanowire sensor.