Direct electrochemistry of cholesterol oxidase and biosensing of cholesterol based on PSS/polymeric ionic liquid–graphene nanocomposite. Issue 64 (21st June 2016)

• Record Type: Journal Article
• Authors: Wu, Shuyao; Wang, Yuxiang; Mao, Hui; Wang, Chong; Xia, Lixin; Zhang, Yu; Ge, Hao; Song, Xi-Ming
• Is Part Of: RSC advances. Volume 6:Issue 64(2016)
• Page Start: 59487
• Page End: 59496
• Publication Date: 2016-06-21
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra06073k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : In this work, a new biosensor based on PSS/polymeric ionic liquids–graphene nanocomposite with excellent conductivity, favourable biocompatibility and good film-forming properties was constructed to detect cholesterol. Abstract : A novel graphene nanocomposite, functionalized by polymeric ionic liquids (PILs) and poly(sodium- p -styrenesulfonate) (PSS), was successfully prepared and exhibited excellent conductivity, favourable biocompatibility and good film-forming properties as an electrode material. TEM showed that the nanocomposite possessed an individual nanosheet-like structure. Owing to the surface modification of graphene, PSS/PILs–GP can not only be well dispersed in aqueous solution, but also possesses a strong negative charge. Due to electrostatic interactions, positively charged cholesterol oxidase (ChOx) can be immobilized onto the surface of PSS/PILs–GP to form the ChOx/PSS/PILs–GP/GC electrode material. UV-vis and FT-IR spectroscopy were used to monitor the assembly process of the nanocomposite. Due to the conductivity and biocompatibility of PSS/PILs–GP, the immobilized ChOx exhibited enhanced direct electron transfer (DET) at a glassy carbon (GC) electrode. Furthermore, the ChOx/PSS/PILs–GP/GC electrode displayed excellent catalytic performance with a wide linear range of 10.5 × 10 −6 to 10.4 × 10 −3 mol L −1, and a low detection limit of 3.5 μmol L −1 for the detection of cholesterol.