A bifunctional reagent regulated ratiometric electrochemiluminescence biosensor constructed on surfactant-assisted synthesis of TiO2 mesocrystals for the sensing of deoxynivalenol

Publication date: 1 May 2019

Source: Talanta, Volume 196

Author(s): Hongli Zheng, Yumin Ke, Huan Yi, Hong Dai, Dandan Fang, Yanyu Lin, Zhensheng Hong, Xiuhua Li

Abstract

Herein, a delicate bifunctional reagent regulated ratiometric electrochemiluminescence (ECL) biosensor was developed for the detection of deoxynivalenol (DON) by virtue of the ratio of two ECL signals from Luminol and tris(4,4′-dicarboxylicacid-2,2′-bipyridyl) ruthenium(II) dichloride (Ru(dcbpy)₃²⁺). Initially, surfactant-assisted synthesis of TiO₂ mesocrystals dispersing in Nafion and ionic liquid (IL) complex film held great promises in loading Ru(dcbpy)₃²⁺ and amplifying the ECL signal. Additionally, helical carbon nanotube (HCNTs) with superior specific area and good conductivity emerging as a scaffold not only realized the high fixing of Luminol, ferrocenecarboxylic acid (FCA) and secondary antibody (Ab₂), but accelerated the electron transfer. It's noteworthy that FCA was first utilized as a bifunctional reagent to regulate the ratiometric ECL sensing mode on account of the influences in enhancing the ECL response of Luminol and quenching the ECL emission of Ru(dcbpy)₃²⁺. On the basis of the sandwich-type immunoreactions between Ab₁, DON and Ab₂, an accurate and sensitive ratiometric ECL immunosensor was established for the detection of DON in a wide range from 0.05 pg/mL to 5 ng/mL with the detection limit of 1.67 × 10⁻² pg/mL.

Graphical abstract

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