Gold nanobipyramids integrated ultrasensitive optical and electrochemical biosensor for Aflatoxin B1 detection

TALANTA

卷:222

Article

Bhardwaj, Hema^1,2,3  Sumana, Gajjala^2,3  Marquette, Christophe A.¹ 

[1] Univ Lyon1, CPE Lyon, ICBMS, 3d FAB,CNRS,INSA,UMR 5246, 43,Bd 11 November 1918, F-69622 Villeurbanne, France

[2] Acad Sci & Innovat Res AcSIR, Ghaziabad 201002, India

[3] CSIR Natl Phys Lab, Dr KS Krishnan Marg, New Delhi 110012, India

关键词: Gold nanobipyramids;    Surface plasmon resonance;    Electrochemical impedance spectroscopy;    Food toxin;    Aflatoxin B-1;    Biosensor;   

DOI  :  10.1016/j.talanta.2020.121578

来源: Elsevier

【 摘 要 】

This work reports the development of an electrical and optical biosensing for label-free detection of Aflatoxin B-1 (AFB(1)) using gold (Au) nanobipyramids (NBPs). AuNBPs were synthesized through a two-step seed-mediated growth process followed by an exchange of capping agent from surfactant to lipoic acid. Pure and monodispersed AuNBPs of 70 nm base length were obtained and deposited on indium tin oxide (ITO)-coated glass substrate modified with self-assembled (3-Aminopropyl) triethoxysilane (APTES) film. The characterization of the ob-tained surfaces using spectroscopy, microscopy and diffractometry confirms the formation of AuNBPs, the conjugation to ITO electrode substrate and the immobilization of anti-AFB(1) antibodies. AuNBPs modified ITO substrates were used for both electrochemical and Surface Plasmon Resonance biosensing studies. Localized Surface Plasmon Resonance (LSPR) local field enhancement was demonstrated. SPR based AFB(1) detection was found to be linear in the 0.1-500 nM range with a limit of detection of 0.4 nM, whereas, impedimetric AFB(1) detection was shown to be linear in the 0.1-25 nM range with a limit of detection of 0.1 nM. The practical utility of the impedimetric sensor was tested in spiked maize samples and 95-100% recovery percentage was found together with low relative standard deviation, proof of the robustness of this AFB(1) sensor.

【 授权许可】

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