Protein-decorated reduced oxide graphene composite and its application to SERS.
A globular protein, β-lactoglobulin (BLG), was used to decorate reduced graphene oxide sheets (RGO) and the obtained BLG-RGO composite can be dispersed in aqueous solution with pH-sensitive solubility. The morphology of the BLG-RGO composite was studied by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results indicate that BLG-RGO is effectively exfoliated with an average thickness of 2.5 nm. UV-vis spectra were performed to examine the reduction degree and determine the optimum concentration of β-lactoglobulin and appropriate pH value. Furthermore, Raman spectra demonstrate that β-Lactoglobulin promotes the chemical reduction process of graphene oxide and benefits to repair the crystal defects. Due to the adsorption of β-Lactoglobulin on the surface of graphene sheets, the BLG-RGO composite was further used as template for Au nanoparticles assembly. These Au nanoparticles assembled on the BLG-RGO composite were shown to yield a large SERS enhancement for Rhodamine 6G.
Key Laboratory of Colloid and Interface Chemistry, Shandong University , Ministry of Education, Jinan, 250100, P. R. China.
Fei
F
Lu
Shaohua
S
Zhang
Hejun
H
Gao
Han
H
Jia
Liqiang
L
Zheng
D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D012995:Solubility; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry
D007782:Lactoglobulins; D010087:Oxides; D014867:Water; D006046:Gold; D006108:Graphite