Virus-mediated layer-by-layer self-assembly of gold nanoparticles for novel humidity sensing

ANYL 136

Chuanbin Mao, cbmao@ou.edu, Aihua Liu, and Naga Venkata Gopal Abbineni. Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
Multilayer thin films containing gold nanoparticles (AuNPs) and arginine-displayed viruses were prepared by layer-by-layer self-assembly on the quartz slide. The formation of the AuNPs/virus films was monitored by sharp surface plasmon resonance (SPR) absorption band arising from AuNPs. The SPR spectra of the films were greatly red-shifted compared with AuNPs in solution, suggesting that AuNPs in the films are linked well with the viruses, which was confirmed by transmission electron microscopy. The virus-terminated films showed enhanced absorbance and red-shift in wavelength in comparison with AuNPs-terminated film, suggesting that the viruses played an important role in linking AuNPs. The SPR spectra of the AuNPs/virus films were systematically red-shifted with the increasing water-vapor contents in the air. A humidity sensor was fabricated from a film containing 4 bilayers of AuNPs/virus by testing its response to the changing of ambient relative humidity. The response of the humidity sensor was fast and reversible.