title: Application on gold nanoparticles-dotted 4-nitrophenylazo graphene in a label-free impedimetric deoxynivalenol immunosensor.
abstract: In this paper, we report a new concept to construct a label-free electrochemical inhibition-based immunosensor for the detection of the mycotoxin deoxynivalenol (DON) in cereal samples. The electrochemical impedance spectroscopy of tris(bipyridine) ruthenium (II) chloride was used as a marker enhanced with gold nanoparticles-dotted 4-nitrophenylazo functionalized graphene (AuNp/G/PhNO2) nanocatalyst mediated in Nafion on a glassy carbon electrode. Under the optimized conditions, the formation of immunocomplexes inhibited electron flow and increased the charge transfer resistance of the sensing interface linearly. The change in impedance was proportional to DON concentrations in the range of 6-30 ng/mL with a sensitivity and detection limit of 32.14 ΩL/ng and 0.3 µg/mL, respectively, which compares favorably with the ELISA result. The proposed sensor had a stability of 80.3%, good precision and selectivity in DON standard solution containing different interfering agents, indicating promising application prospect for this strategy in designing impedimetric, electrochemiluminescent, voltammetric or amperometric sensors.
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. csunday@uwc.ac.za.
authors: Christopher Edozie
authors: CE
authors: Sunday
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. masikinimilua@gmail.com.
authors: Milua
authors: M
authors: Masikini
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. 2724554@myuwc.ac.za.
authors: Lindsay
authors: L
authors: Wilson
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. 2734778@myuwc.ac.za.
authors: Candice
authors: C
authors: Rassie
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. twaryo@uwc.ac.za.
authors: Tesfaye
authors: T
authors: Waryo
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. pbaker@uwc.ac.za.
authors: Pricilla G L
authors: PG
authors: Baker
authors: Sensor Laboratory, Chemistry Department, University of the Western Cape, Private Bag X 17, Bellville 7535, South Africa. eiwuoha@uwc.ac.za.
authors: Emmanuel I
authors: EI
authors: Iwuoha
mesh_terms: D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy; D002523:Edible Grain / Q000737:chemistry*; D005465:Fluorocarbon Polymers; D005504:Food Analysis; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D014255:Trichothecenes / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D005465:Fluorocarbon Polymers; D014255:Trichothecenes; C040402:perfluorosulfonic acid; D006046:Gold; D006108:Graphite; C007262:deoxynivalenol