Label Free Poly(2,5-dimethoxyaniline)-Multi-Walled Carbon Nanotubes Impedimetric Immunosensor for Fumonisin B₁ Detection

Milua Masikini; Avril R Williams; Christopher E Sunday; Tesfaye T Waryo; Ezo Nxusani; Lindsay Wilson; Sinazo Qakala; Mawethu Bilibana; Samantha Douman; Anovuyo Jonnas; Priscilla G L Baker; Emmanuel I Iwuoha

doi:10.3390/ma9040273

Label Free Poly(2,5-dimethoxyaniline)-Multi-Walled Carbon Nanotubes Impedimetric Immunosensor for Fumonisin B₁ Detection

Materials (Basel). 2016 Apr 7;9(4):273. doi: 10.3390/ma9040273.

Authors

Affiliations

¹ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. mmasikini@uwc.ac.za.
² Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Bridgetown BB11000, Barbados. avril.williams@cavehill.uwi.edu.
³ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. csunday@uwc.ac.za.
⁴ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. twaryo@uwc.ac.za.
⁵ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. 2861275@myuwc.ac.za.
⁶ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. 2724554@myuwc.ac.za.
⁷ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. 2346099@myuwc.ac.za.
⁸ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. 2324593@myuwc.ac.za.
⁹ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. 2810366@myuwc.ac.za.
¹⁰ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. 3053138@myuwc.ac.za.
¹¹ SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. pbaker@uwc.ac.za.
¹² SensorLab, Department of Chemistry, University of the Western Cape Robert Sobukwe Road, Bellville 7535, Cape Town, South Africa. eiwuoha@uwc.ac.za.

Abstract

An impedimetric immunosensor for fumonisin B₁ (FB₁) was developed from a poly(2,5-dimethoxyaniline)-multi-walled carbon nanotube (PDMA-MWCNT) composite on the surface of glassy carbon electrode (GCE). The composite was prepared electrochemically and characterized using cyclic voltammetry. The preparation of the FB₁ immunosensor involved the drop-coating of a bovine serum albumin mixture of the anti-fumonisin antibody (anti-Fms) onto the composite polymer-modified GCE. The electrochemical impedance spectroscopy (EIS) responses of the FB₁ immunosensor (GCE/PDMA-MWCNT/anti-Fms) have a linear range of 7 to 49 ng·L^-1, and the corresponding sensitivity and detection limits are 0.272 kΩ L·ng^-1 and 3.8 pg·L^-1, respectively. The limit of detection of the immunosensor for certified corn sample (i.e., certified reference material) is 0.014 ppm FB₁, which is in excellent agreement with the value published by the vendors and significantly more accurate than that obtained with enzyme-linked immunosorbent assay (ELISA).

Keywords: anti-fumonisin antibody; certified reference materials; electrochemical impedance spectroscopy; fumonisin B1; immunosensor; poly(2,5-dimethoxyaniline)-multi-walled carbon nanotubes.