title: Graphene-Orange II composite nanosheets with electroactive functions as label-free aptasensing platform for "signal-on" detection of protein.
abstract: The combination of novel nanomaterials and biomolecule recognition units is promising in developing sensitive biosensors. This paper presents a facile approach for the preparation of water-soluble electroactive dye-Orange II functionalized graphene nanosheets (O-GNs). The successful attachment of Orange II on the surface of graphene nanosheets not only prevents the agglomeration of the as-formed graphene nanocomposite in aqueous media, but also endows graphene nanosheets with excellent electroactive property. Integrating the unique properties of the as-prepared O-GNs (high conductivity, high specific surface area and electroactive function) with high affinity and specificity of aptamer, a new label-free electrochemical biosensing concept is demonstrated for the "signal-on" detection of targets such as thrombin and lysozyme. The present O-GNs-based aptasensor exhibits good current response to the above proteins. The linear ranges for thrombin and lysozyme are 1.0 × 10(-12)-4.0 × 10(-10)M and 5.0 × 10(-12)-7.0 × 10(-10)M, with the detection limit of 3.5 × 10(-13)M and 1.0 × 10(-12)M, respectively. In contrast to the common laborious and expensive labeling approaches, the present O-GNs based aptasensing process is highly simple, cost-efficient and does not need labeling and modification of aptamers or introduce additional electrochemical probes.
authors: Research Center for Environmental Science and Engineering, Shanxi University, Taiyuan 030006, China. guoyj@sxu.edu.cn
authors: Yujing
authors: Y
authors: Guo
authors: Yujie
authors: Y
authors: Han
authors: Yanxiu
authors: Y
authors: Guo
authors: Chuan
authors: C
authors: Dong
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry; D001557:Benzenesulfonates / Q000737:chemistry; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D009113:Muramidase / Q000737:chemistry / Q000302:isolation & purification*; D049329:Nanostructures / Q000737:chemistry; D013917:Thrombin / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D052157:Aptamers, Nucleotide; D001391:Azo Compounds; D001557:Benzenesulfonates; D006046:Gold; D006108:Graphite; D009113:Muramidase; D013917:Thrombin; C014722:2-naphthol orange