Colorimetric aflatoxins immunoassay by using silica nanoparticles decorated with gold nanoparticles

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 246; p. 118999
• Main Authors: Althagafi, Ismail I., Ahmed, Saleh A., El-Said, Waleed A.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.02.2021
• Subjects: Aflatoxin antibodies; Aflatoxins - analysis; Colorimetry; Environmental monitoring; Food safety; Gold; Immunoassay; Mesoporous silica@gold nanocomposite; Metal Nanoparticles; Mycotoxins; Optical sensor; Silicon Dioxide; Optical sensor; Mesoporous silica@gold nanocomposite; Food safety; Environmental monitoring; Aflatoxin antibodies; Mycotoxins
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2020.118999

Nanomaterials-based colorimetric immunoassays showed increasing attention for monitoring different biomarkers because of their unique optical and electrical features. Here, a highly sensitive and selective optical sensor was described for the determination of different aflatoxins (AFs). Mesoporous silica nanoparticles (m-SNPs) with an average particle size of 40 nm were prepared by the sol-gel method and then decorated with gold nanoparticles (AuNPs). The Au NPs@m-SiNPs nanocomposite with an average particle size of 66 nm was modified with AFs antibodies. The assay includes the following steps: the Au NPs@m-SiNPs nanocomposite was immersed with AFs antibodies, and then the AFs-Ab/Au NPs@m-SiNPs was used as a probe for AFs detection. The interaction between the AFs-Ab/Au NPs@m-SiNPs and the AFs has resulted in a change in its color from pink to violet. Measurements are performed by absorptiometry at a wavelength of 425 nm. The immunoassay works in the concentration range from 1 ng·mL−1 to 75 ng·mL−1 AFB1 and has a limit of detection 0.16 ng·mL−1 (at S/N = 3). The assay was applied to the determination of AFs in different food samples spiked with AFS. Finally, the assay was used to detect AFs in a real sample, and the LC-MS technique was used to verify the results. [Display omitted] •Silica/gold nanocomposite modified with anti-AFB1 was used as AFB1 sensor.•UV–vis was used for monitoring different concentrations of AFB1.•The LOD of the AFB1-anti/Au/MSNPs found to be 0.16 ng/mL.•The developed system was used to detected AFB1 in foodstuff samples.