Label-free detection of aflatoxin M1 with electrochemical Fe3O4/polyaniline-based aptasensor.

Label-free detection of aflatoxin M1 with electrochemical Fe3O4/polyaniline-based aptasensor.

Materials science & engineering. C, Materials for biological applications (2013-03-19)

Binh Hai Nguyen, Lam Dai Tran, Quan Phuc Do, Huy Le Nguyen, Ngoc Huan Tran, Phuc Xuan Nguyen

ABSTRACT

The selective detection of ultratrace amounts of aflatoxin M1 (AFM1) is extremely important for food safety since it is the most toxic mycotoxin class that is allowed to be present on cow milk with strictly low regulatory levels. In this work, Fe3O4 incorporated polyaniline (Fe3O4/PANi) film has been polymerized on interdigitated electrode (IDE) as sensitive film for AFM1 electrochemical biosensor. The immobilized aptamers as an affinity capture reagent and magnetic nanoparticles for signal amplification element have been employed in the sensing platform. Label-free and direct detection of the aptamer-AFM1 on Fe3O4/PANi interface were performed via electrochemical signal change, acquired by cyclic and square wave voltammetries. With a simplified strategy, this electrochemical aptasensor shows a good sensitivity to AFM1 in the range of 6-60 ng·L(-1), with the detection limit of 1.98 ng·L(-1). The results open up the path for designing cost effective aptasensors for other biomedical applications.

MATERIALS

Product Number

Brand

Product Description

A6428

Sigma-Aldrich

Aflatoxin M₁, from Aspergillus flavus

700320

Sigma-Aldrich

Iron oxide(II,III), magnetic nanoparticles solution, 5 nm avg. part. size, 5 mg/mL in toluene

700304

Sigma-Aldrich

Iron oxide(II,III), magnetic nanoparticles solution, 20 nm avg. part. size, 5 mg/mL in toluene

700312

Sigma-Aldrich

Iron oxide(II,III), magnetic nanoparticles solution, 10 nm avg. part. size, 5 mg/mL in toluene

725331

Sigma-Aldrich

Iron oxide(II,III), magnetic nanoparticles solution, 5 nm avg. part. size, 5 mg/mL in H₂O

725366

Sigma-Aldrich

Iron oxide(II,III), magnetic nanoparticles solution, 20 nm avg. part. size, 5 mg/mL in H₂O

725358

Sigma-Aldrich

Iron oxide(II,III), magnetic nanoparticles solution, 10 nm avg. part. size, 5 mg/mL in H₂O

518158

Sigma-Aldrich

Iron(II,III) oxide, 99.99% trace metals basis

310069

Sigma-Aldrich

Iron(II,III) oxide, powder, <5 μm, 95%

637106

Sigma-Aldrich

Iron(II,III) oxide, nanopowder, 50-100 nm particle size (SEM), 97% trace metals basis

34031

Supelco

Aflatoxin M₁ solution, 0.5 μg/mL in acetonitrile, analytical standard