An Ultrasensitive Electrochemiluminescent Immunoassay for Aflatoxin M1 in Milk, Based on Extraction by Magnetic Graphene and Detection by Antibody-Labeled CdTe Quantumn Dots-Carbon Nanotubes Nanocomposite
Open Access
- 29 April 2013
- Vol. 5 (5), 865-883
- https://doi.org/10.3390/toxins5050865
Abstract
An ultrasensitive electrochemiluminescent immunoassay (ECLIA) for aflatoxins M1 (ATM1) in milk using magnetic Fe3O4-graphene oxides (Fe-GO) as the absorbent and antibody-labeled cadmium telluride quantum dots (CdTe QDs) as the signal tag is presented. Firstly, Fe3O4 nanoparticles were immobilized on GO to fabricate the magnetic nanocomposites, which were used as absorbent to ATM1. Secondly, aflatoxin M1 antibody (primary antibody, ATM1 Ab1), was attached to the surface of the CdTe QDs-carbon nanotubes nanocomposite to form the signal tag (ATM1 Ab1/CdTe-CNT). The above materials were characterized. The optimal experimental conditions were obtained. Thirdly, Fe-GO was employed for extraction of ATM1 in milk. Results indicated that it can adsorb ATM1 efficiently and selectively within a large extent of pH from 3.0 to 8.0. Adsorption processes reached 95% of the equilibrium within 10 min. Lastly, the ATM1 with a serial of concentrations absorbed on Fe-GO was conjugated with ATM1 Ab1/CdTe-CNT signal tag based on sandwich immunoassay. The immunocomplex can emit a strong ECL signal whose intensity depended linearly on the logarithm of ATM1 concentration from 1.0 to 1.0 × 105 pg/mL, with the detection limit (LOD) of 0.3 pg/mL (S/N = 3). The method was more sensitive for ATM1 detection compared to the ELISA method. Finally, ten samples of milk were tested based on the immunoassay. The method is fast and requires very little sample preparation, which was suitable for high-throughput screening of mycotoxins in food.Keywords
This publication has 23 references indexed in Scilit:
- Development of an impedimetric aflatoxin M1 biosensor based on a DNA probe and gold nanoparticlesBiosensors and Bioelectronics, 2011
- Electrochemiluminescence immunoassay at a nanoporous gold leaf electrode and using CdTe quantun dots as labelsMicrochimica Acta, 2010
- Development of an Electrochemical Biosensor for the Detection of Aflatoxin M1 in MilkSensors, 2010
- Quantum Dots Based Electrochemiluminescent Immunosensor by Coupling Enzymatic Amplification with Self-Produced Coreactant from Oxygen ReductionAnalytical Chemistry, 2010
- Development of an Electrochemical Immunosensor for Fumonisins Detection in FoodsToxins, 2010
- Enhanced electrochemiluminescence of CdSe quantum dots composited with CNTs and PDDA for sensitive immunoassayBiosensors and Bioelectronics, 2009
- Kinetic insight into the mechanism of cholinesterasterase inhibition by aflatoxin B1 to develop biosensorsBiosensors and Bioelectronics, 2009
- Enzyme-Linked Immunosorbent Assay (ELISA) based on superparamagnetic nanoparticles for aflatoxin M1 detectionTalanta, 2008
- Immunochemical methods for rapid mycotoxin detection: Evolution from single to multiple analyte screening: A reviewFood Additives & Contaminants, 2007
- Biomedical and clinical applications of immunoassays and immunosensors for tumor markersTrAC Trends in Analytical Chemistry, 2007