Template-Directed Hierarchical Self-Assembly of Graphene Based Hybrid Structure for Electrochemical Biosensing
2013 (English)In: Biosensors and Bioelectronics, ISSN 0956-5663, EISSN 1873-4235, Vol. 49, 53-62 p.Article in journal (Refereed) Published
A template-directed self-assembly approach, using functionalised graphene as a fundamental building block to obtain a hierarchically ordered graphene-enzyme-nanoparticle bioelectrode for electrochemical biosensing, is reported. An anionic surfactant was used to prepare a responsive, functional interface and direct the assembly on the surface of the graphene template. The surfactant molecules altered the electrostatic charges of graphene, thereby providing a convenient template-directed assembly approach to a free-standing planar sheet of sp(2) carbons. Cholesterol oxidase and cholesterol esterase were assembled on the surface of graphene by intermolecular attractive forces while gold nanoparticles are incorporated into the hetero-assembly to enhance the electro-bio-catalytic activity. Hydrogen peroxide and cholesterol were used as two representative analytes to demonstrate the electrochemical sensing performance of the graphene-based hybrid structure. The bioelectrode exhibited a linear response to H2O2 from 0.01 to 14 mM, with a detection limit of 25 nM (S/N=3). The amperometric response with cholesterol had a linear range from 0.05 to 0.35 mM, sensitivity of 3.14 mu A/mu M/cm(2) and a detection limit of 0.05 mu M. The apparent Michaelis-Menten constant (K-m(app)) was calculated to be 1.22 mM. This promising approach provides a novel methodology for template-directed bio-self-assembly over planar sp(2) carbons of a graphene sheet and furnishes the basis for fabrication of ultra-sensitive and efficient electrochemical biosensors.
Place, publisher, year, edition, pages
Elsevier, 2013. Vol. 49, 53-62 p.
Medical Laboratory and Measurements Technologies
IdentifiersURN: urn:nbn:se:liu:diva-91866DOI: 10.1016/j.bios.2013.04.004ISI: 000323396700009OAI: oai:DiVA.org:liu-91866DiVA: diva2:619390
ProjectsHierarchicalself-assembly, Templatedirected hybridnanomaterial, Graphene Nano-biointerface, Biosensor
FunderSwedish Research Council, VR- 2011-6058357EU, FP7, Seventh Framework Programme, PIIF-GA-2009-254955