Fast determination of citreoviridin residues in rice using a monoclonal antibody-based immunochromatographic strip assay

Abstract

Citreoviridin (CTV) is a toxic secondary metabolite that can be found in mouldy cereals. In this study, a sensitive and ethanol-tolerant anti-CTV monoclonal antibody (6B2) was produced with a 50% inhibition concentration of 4.1 ng/mL and then labelled using gold nanoparticle (GNP). Based on competitive inhibition of the binding of CTV-COOH-BSA conjugate sprayed onto a membrane to limited GNP-labelled antibody by free CTV in the samples, an easy-to-operate immunochromatographic strip (ICS) was developed for the fast screening of CTV in rice. The results are seen as a colour change within 5-10 min. We used relatively safe ethanol instead of highly toxic methanol or chloroform as the extraction solution and found a visible detection limit of 100 μg/ kg and cut-off value of 1000 μg/kg. The developed ICS assay worked well and represented a reliable, safe, fast and a highthroughput method for the detection of CTV residues in rice samples.

Development of a colloidal gold strip assay for the detection of total homocysteine in serum samples

“…Excess CG-labeled mAb would migrate to the C line and be captured by the goat anti-mouse IgG antibody, forming a red C line. 30 For quantitative analysis, the color intensity of the T line was determined with a strip scan reader 5 min after the addition of the sample and the results of T/C were calculated representing the T line signals against the C line signals.…”

Fluorescent strip sensor for rapid and ultrasensitive determination of fluoroquinolones in fish and milk

“…Immunogens were prepared by combining Nor-1 (M w = 405.7) with carrier proteins using the activated ester method. 31,32 In brief, Nor-1 (9 mg), NHS (7.7 mg) and EDC•HCl (12.7 mg) were dissolved in N,N-dimethylformamide (DMF, 0.7 mL), N,N-dimethylformamide (DMF, 0.1 mL) and 4-morpholineethanesulfonic acid solution (MES, 0.1 M, 0.1 mL), respectively. Then, the EDC•HCl solution and the NHS solution were added dropwise into the Nor-1 solution at RT, and the mixture was allowed to react for 4 h under constant stirring.…”

Monoclonal antibody production and development of immunochromatographic strip assays for screening of the herbicide bispyribac-sodium in rice

“…Rice samples were obtained from local markets and extracted as previously reported. 21,31 The rice was crushed in a pulverizer, and 10 g of rice our sample was added into 15 mL ultrapure water and oscillated for 3 h at RT. Then, the soaked sample was extracted with 60 mL of ethanol/water (4/6 v/v) by shaking for 30 min.…”