Competitive Bio-Barcode Immunoassay for Highly Sensitive Detection of Parathion Based on Bimetallic Nanozyme Catalysis

et al. 2022

Front. Nutr.

Self Cite

Carbendazim (CBZ), a systemic, broad-spectrum benzimidazole fungicide, is widely used to control fungal diseases in agricultural products. Its residues might pose risks to human health and the environment. Therefore, it is warranted to establish a rapid and reliable method for its residual quantification. Herein, we proposed a competitive assay that combined aptamer (DNA) specific recognition and bimetallic nanozyme gold@platinum (Au@Pt) catalysis to trace the CBZ residue. The DNA was labeled onto bimetallic nanozyme Au@Pt surface to produce Au@Pt probes (Au@Pt-DNA). The magnetic Fe3O4 was functionalized with a complementary strand of DNA (C-DNA) to form Fe3O4 probes (Fe3O4-C-DNA). Subsequently, the CBZ and the Fe3O4 probes competitively react with Au@Pt probes to form two Au@Pt-DNA biosensors (Au@Pt-ssDNA-CBZ and Au@Pt-dsDNA-Fe3O4). The Au@Pt-ssDNA-CBZ biosensor was designed for qualitative analysis through a naked-eye visualization strategy in the presence of CBZ. Meanwhile, Au@Pt-dsDNA-Fe3O4 biosensor was developed to quantitatively analyze CBZ using a multifunctional microplate reader. A competitive assay based on the dual-mode Au@Pt-DNA biosensors was established for onsite sensitive determination of CBZ. The limit of detection (LOD) and recoveries of the developed assay were 0.038 ng/mg and 71.88-110.11%, with relative standard deviations (RSDs) ranging between 3.15 and 10.91%. The assay demonstrated a good correlation with data acquired from liquid chromatography coupled with mass spectrometry/mass spectrometry analysis. In summary, the proposed competitive assay based on dual-mode Au@Pt-DNA biosensors might have a great potential for onsite sensitive detection of pesticides in agro-products.

Section: Preparation Of Au@pt Nanomaterialsmentioning

confidence: 99%

A Competitive Assay Based on Dual-Mode Au@Pt-DNA Biosensors for On-Site Sensitive Determination of Carbendazim Fungicide in Agricultural Products

Zhai

et al. 2022

Front. Nutr.

Self Cite

“…Besides, nanozymes are supposed to be more stable and have a lower cost. Therefore, more and more NLISA are being fabricated for the quantification of pesticides [111][112][113][114][115].…”

Section: Nanozyme-based Immunosensorsmentioning

confidence: 99%

Nanozyme-Participated Biosensing of Pesticides and Cholinesterases: A Critical Review

Zhu

et al. 2021

Biosensors

To improve the output and quality of agricultural products, pesticides are globally utilized as an efficient tool to protect crops from insects. However, given that most pesticides used are difficult to decompose, they inevitably remain in agricultural products and are further enriched into food chains and ecosystems, posing great threats to human health and the environment. Thus, developing efficient methods and tools to monitor pesticide residues and related biomarkers (acetylcholinesterase and butylcholinesterase) became quite significant. With the advantages of excellent stability, tailorable catalytic performance, low cost, and easy mass production, nanomaterials with enzyme-like properties (nanozymes) are extensively utilized in fields ranging from biomedicine to environmental remediation. Especially, with the catalytic nature to offer amplified signals for highly sensitive detection, nanozymes were finding potential applications in the sensing of various analytes, including pesticides and their biomarkers. To highlight the progress in this field, here the sensing principles of pesticides and cholinesterases based on nanozyme catalysis are definitively summarized, and emerging detection methods and technologies with the participation of nanozymes are critically discussed. Importantly, typical examples are introduced to reveal the promising use of nanozymes. Also, some challenges in the field and future trends are proposed, with the hope of inspiring more efforts to advance nanozyme-involved sensors for pesticides and cholinesterases.

“…Immunoassays or immunosensors are constructed to achieve precise quantitative detection of metal ions in the field, ranging from environment analysis to food safety (Xiao et al, 2018;Xing et al, 2014). Similar to the immunoassay for other small molecular compounds, a generally competitive format is the basis for the immunoassay for metal ions, which is determined by only one epitope (Chen et al, 2020;Galvidis et al, 2020;Huo et al, 2019). However, this has obvious difference from other small molecules, mostly requiring the addition of a molar excess of the chelator to convert the free metal ions in samples to metal-chelate complexes (except some anti-GSH/MNA-Hg(II) antibodies) ( Figure 3).…”

Section: As Specific Recognition Elements For Immunoassaymentioning

confidence: 99%

Antibody developments for metal ions and their applications

Wang

Zhang

Food and Agricultural Immunology

2020

Metal ions are beneficial or toxic in part depending on their identity, valence state, and concentration. Antibodies against radioactive metal ions can be used in medical diagnosis and therapy, while antibodies against heavy metal ions are widely used in the trace element analysis of the immunoassay. This review focuses on the recent advances in antibody developments for metal ions and their applications. We exhaustively enumerated 18 chelate or ligand structures for metal hapten synthesis, which were proven to produce antibodies that cover almost 33 metal ions. The binding properties of these antibodies for their corresponding haptens were also discussed both in the structural foundation and molecular foundation. Furthermore, the representative applications of the antibodies used in medical diagnostics and therapy, and immunoassays were summarized. Finally, we illustrated the present challenges in high specific metal ion antibody preparation, and in immunoassay development. The future perspectives were also discussed.