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Mercury is a major pollutant in food crops. In this study, we synthesized an anti-mercury monoclonal antibody (mAb; IC50 was 0.606 ng mL−1) with high sensitivity and specificity and different immunogens and coating antigens and developed an immuno-chromatographic assay (ICA) for the detection of mercury in rice. The ICA strip had a visible detection limit of 20 ng g−1 and a cut-off value of 500 ng g−1 in rice. The performance of the ICA strip was consistent with that of ICP-MS and ic-ELISA. The recoveries of mercury in rice ranged from 94.5% to 113.7% with ic-ELISA and from 93.6% to 116.45% with ICP-MS. Qualitative analysis by ICA can be obtained with the naked eye. The ICA strip is an effective and practical method for the rapid and high-throughput determination of mercury in rice. [ABSTRACT FROM AUTHOR]

• A novel AMT hapten was designed by adding a carboxyl group with 4-C spacer arms. • The sensitive and specific anti-AMT mAb was prepared based on hapten design. • The immunochromatographic assay was firstly developed for AMT rapid detection. • The established mehod can meet the requirements of MRLs for AMT residues in foods. Amitraz (AMT) is a broad-spectrum formamidine insecticide and acaricide. In this study, we produced an anti-AMT monoclonal antibody (mAb) with high performance. The half-maximal inhibitory concentration of the anti-AMT mAb was 4.418 ng/mL, the cross reactivity with other insecticides was negligible, and an affinity constant was 2.06 × 109 mmol/L. Additionally, we developed an immunochromatographic assay for the rapid detection of AMT residues in oranges, tomatoes, and eggplants. The cut-off values were 2000 μg/kg in oranges and tomato samples and 1000 μg/kg in eggplant samples and the calculated limits of detection were 14.521 μg/kg, 6.281 μg/kg, and 3.518 μg/kg in oranges, tomatoes, and eggplants, respectively, meeting the detection requirements for AMT in fruits and vegetables. The recovery rates ranged between 95.8 % and 105.2 %, consistent with the recovery rates obtained via LC-MS/MS. Our developed immunochromatographic assay can effectively, accurately, and rapidly determine AMT residues in oranges, tomatoes, and eggplants. [ABSTRACT FROM AUTHOR]

In developing countries, pesticides such as triazophos (TZP) are widely used in agriculture. However, the misuse TZP poses a threat to human health and the environment due to its high chemical and photochemical stability. In this study, we developed a lateral flow assay to determine TZP in cucumber. We produced anti-TZP monoclonal antibody with half inhibitory concentration of 2.013 ng/mL according to ELISA. Under optimum conditions, the lateral flow assay had TZP cut-off values of 100 ng/mL in 0.01 M PBS and 250 ng/mL in cucumber, and the results could be visualised with the naked eye in 5 min. our findings revealed that lateral flow assay is a rapid and sensitive method for detect TZP in cucumber. [ABSTRACT FROM AUTHOR]

Aminophylline (AMP), a bronchodilator drug, is a modified form of theophylline (the pharmacological active ingredient). AMP is often given to treat respiratory diseases, including bronchial asthma, blocked emphysema, panting bronchitis, and cardiogenic asthma. In this study, we developed a rapid and sensitive method to determine AMP concentration in mouse serum. A sensitive monoclonal antibody against AMP was produced by immunizing BALB/c mice with a well-characterized AMP2-keyhole limpet hemocyanin and coating antigen (hapten-AMP1-OVA). The coating antigen and goat anti-mouse IgG antibody were sprayed onto a nitrocellulose membrane representing the test and control lines, respectively. Under optimized conditions, the cut-off limits of the test strip were 50 ng/mL in 0.01 M phosphate buffered saline (pH 7.4) and 250 ng/mL in serum. The results were obtained within 10 min and revealed that this immunochromatographic strip test is a sensitive, rapid, and simple tool for the detection of AMP in serum. [ABSTRACT FROM AUTHOR]

A rapid, specific and sensitive method based an immunochromatographic strip test has been developed for the determination of sodium nifurstyrenate (NFS) residues in fish. Sample preparation procedure includes ultrasonic bath extraction with acetonitrile, sample centrifugation at 8000 rpm for 10 min, filtration through the 0.22 µm membrane filter, and drying over nitrogen (60°C) and res-suspension. The antigen (NFS-ovalbumin) and a goat anti-mouse IgG antibody were drawn onto a nitrocellulose membrane as the test line and control line, respectively. Under optimized conditions, the NFS cut-off limits for test strips was determined as 5 ng/mL in 0.01 M phosphate buffered saline and 10 ng/mL in fish. Results were obtained within 5 min. Our data suggests this immunochromatographic assay can be used for the sensitive, rapid, and specific on-site screening for NFS in fish. [ABSTRACT FROM AUTHOR]

A highly sensitive, specific, and rapid immunochromatographic assay for halofuginone (HFG) has been developed. A well-characterized immunogenic conjugate of HFG with bovine serum albumin was produced using the N,N″-Carbonyldiimidazole method. A sensitive monoclonal antibody specific for HFG was then generated by immunizing BALB/c mic with the HFG conjugate. The antigen, HFG-CDI-ovalbumin and goat anti-mouse IgG were attached to a nitrocellulose membrane as the test line and the control line, respectively to produce an immunochromatographic test strip for the rapid detection of HFG in milk. Under optimized conditions, the detection limits of the semi-quantitative test strip for HFG were as low as 50 ng/mL in 0.01 M PBS (pH 7.4) and 100 ng/mL in milk. All the results were obtained within 5 min. The newly developed immunochromatographic assay provides a sensitive, rapid, and specific procedure for on-site screening for HFG. [ABSTRACT FROM AUTHOR]

Humans and animals are exposed to mycotoxins naturally present in foods. Ochratoxin A (OTA), one of the most abundant and toxic mycotoxins, is ubiquitous in nature and harmful to humans and animals. In this study, we developed a rapid, simple, specific, and sensitive lateral-flow immunochromatographic assay for detection of OTA in 0.01 M phosphate-buffered saline solution (PBS) (pH 7.4) and in red wine. We produced sensitive and selective monoclonal antibody against OTA. Under optimized conditions, the cut-off limit of the test strip was 10 ng/mL OTA in 0.01 M PBS (pH 7.4) and in red wine. The results were obtained within 10 min. Therefore, our developed method is useful for the detection of OTA in red wine. [ABSTRACT FROM AUTHOR]

In this paper, we describe the development of a rapid, simple, specific, and sensitive immunochromatographic strip test based on an antibody-antigen reaction for detection of tulathromycin (TULA) in samples of 0.01 M PBS pH 7.4, pure milk and honey. The monoclonal antibodies specifically recognized the corresponding antigens produced in our laboratory. Under optimized conditions, the cut-off limits of the test strips for TULA in 0.01 M PBS pH 7.4 was found to be 2.5 ng/mL. Meanwhile, with simple preparation for detection in pure milk and honey samples, the cut-off limits for TULA were found to be 5 and 10 ng/mL, respectively. Each test can be evaluated in 5 min. In summary, this lateral-flow device provides a sensitive, effective, specific, and rapid method for detection of TULA residues in food matrix. [ABSTRACT FROM AUTHOR]

The presence of pesticide residues in crops is a significant public concern. Due to the large number of samples and pesticides, a reliable, simple, cost-effective, and high-throughput analytic method is required. In this study, we developed a gold nanoparticle (GNP) immunochromatographic assay (ICA) for the rapid detection of 6-benzylaminopurine (6-BA) residues in bean sprouts. A monoclonal antibody against 6-BA, having a half-maximum inhibition concentration of 2.25 ng/mL, was labeled with GNPs and fixed onto a glass fiber membrane to create a conjugate pad. Coating antigen and goat anti-mouse antibody were sprayed onto a nitrocellulose membrane to form the test line and control line, respectively. The visual limit of detection and cutoff limit of ICA were 10 and 80 ng/g in bean sprouts, respectively. The results of ICA were obtained within 10 min with the naked eye. Therefore, ICA is a rapid tool for the on-site screening and detection of 6-BA in bean sprouts. [ABSTRACT FROM AUTHOR]

Procaine (PRC) is a local anaesthetic used in the treatment of several disease related to ageing, asthma, and arthritis. In this study, we describe a rapid, sensitive, simple, and accurate method for the determination of PRC in milk, using an immunochromatographic test strip. For the immunochromatographic test, antigen (PRC-bovine serum albumin) and goat anti-mouse IgG were drawn onto a nitrocellulose membrane representing the control line and test line. The test was developed with a sensitive monoclonal antibody specific for PRC, generated by immunizing BALB/c mice with a well-characterized PRC- Keyhole limpet hemocyanin conjugate, produced in our laboratory. Under optimized conditions, the semi-quantitative test strip was able to detect PRC at concentrations down to 1 ng/mL in both 0.01 M phosphate buffer saline (pH 7.4) and milk samples. All results were obtained within 5 min. Our data indicate that the immunochromatographic assay is capable of sensitive, rapid, and specific on-site screening of PRC. [ABSTRACT FROM AUTHOR]

Clonidine (CLO) preferentially stimulates central α-2-adrenoceptors and causes both desirable and undesirable effects. Undesirable effects include sedation and withdrawal reactions, which occur as a sudden rise in arterial pressure, nervousness, agitation, and increased heart rate. An immunochromatographic test strip was developed for the rapid simultaneous detection of CLO and its cross-reactivity with apraclonidine (ACLO) in pig urine. The antigen CLO-OVA and goat anti-mouse IgG were attached to a nitrocellulose membrane as control line and test line. The cut-off limits of the test strips for CLO and ACLO were found to be 2.5 ng/mL in both 0.01 M PBS (pH 7.4) and pig urine. All the results were obtained within 5 min. The results revealed that the developed method is a sensitive, rapid, and simple tool for the detection of CLO and ACLO. [ABSTRACT FROM AUTHOR]

A sensitive monoclonal antibody (mAb) (1H1) against fumonisin B1 (FB1) was produced in our laboratory. A rapid, simple, and an immunochromatographic strip has been developed for the ultrasensitive detection of FB1 in corn samples. Under the optimized condition, the cut-off limits of test strips for FB1 were found to be 50 ng/mL in 0.01 M PBS and 25 ng/mL in corn samples. Results could be obtained within 5 min. The results revealed that the developed method is a rapid, sensitive, and simple tool for the detection of FB1. [ABSTRACT FROM AUTHOR]

Zearalenone (ZEN) is a mycotoxin produced by fungal species which are widespread in nature and commonly contaminate many cereal grains, such as wheat, maize, corn, barley, and other cereal grains. An immunochromatographic (ICA) test strip was developed for the rapid simultaneous detection of ZEN and its metabolite in corn flour samples. For the ICA test, antigen (ZEN-BSA) and goat anti-mouse IgG were, respectively, drawn on nitrocellulose membrane as control line and test line. Under the optimized condition, the cut-off limits of test strips for ZEN, α-ZAL, and β-ZAL were found to be 0.5 ng/mL in 0.01 M PBS and 50 ng/mL in corn flour samples, meanwhile α-ZOL, β-ZOL, and ZEA were found to be 1 ng/mL in 0.01 M PBS and 75 ng/mL in corn flour samples. Our data indicate that the ICA is sensitive, rapid, cost-effective, and specific on-site screening for ZEN and its metabolite. [ABSTRACT FROM AUTHOR]

An immunochromatographic strip was developed for detection of acetamiprid (AC) and cross-reactivity with thiacloprid (TC) in cucumber and apple samples. This detection system was developed based on a sensitive and specific monoclonal antibody produced in our laboratory. Under optimized conditions, the cut-off limits of the test strip for AC were found to be 1 and 0.25 ng/mL for TC in phosphate-buffered saline. Meanwhile, with simple preparation for detection cucumber and apple samples, the cut-off limits for AC were found to be 5 and 2.5 ng/mL for TC in cucumber samples. The immunochromatographic assay also revealed AC cut-off values of 30 and 15 ng/mL in apple samples. Each test can be evaluated within 5 min. The data indicate that the method is sensitive, rapid, specific, and has the advantages of simplicity; therefore, this immunochromatographic assay is a useful screening method for detection of AC and TC residues in cucumber and apple samples. [ABSTRACT FROM PUBLISHER]

In this study, we developed an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and an immunochromatographic assay to detect the furazolidone metabolite, 3-amino-2-oxazolidinone (AOZ). The detection of AOZ was based on the AOZ derivative 3-([2-nitrophenyl]methyleneamino]-2-oxazolidinone (2-NPAOZ). 3-([(3-Carboxyphenyl)methylene]-amino)-2-oxazolidinone (2-CPAOZ) was used as the immunizing hapten and a conjugate of AOZ and glyoxylic acid (AOZ-A) was used as the coating hapten. The monoclonal anti-2-NPAOZ antibody, 5G12, was generated with a half-inhibitory concentration (IC50) of 0.2 ng/mL and a line of 0.06–0.66 ng/mL. Its cross reactivity with other analogues was less than 8%. Spiked catfish samples (0.1, 0.2, and 0.5 μg/kg) were analyzed with the proposed system. The ic-ELISA showed a recovery range of 86.2–118.5% and the intra-assay and inter-assay coefficients of variation ranged from 4.3% to 9.4%. Under the optimum assay conditions, the immunochromatographic assay had a visual cut-off value of 0.5 μg/kg in catfish samples. Both methods can be used to detect AOZ in catfish samples. [ABSTRACT FROM AUTHOR]

A rapid, simple, and sensitive immunochromatographic strip test has been developed to detect aldicarb (ALD) in 0.01 M phosphate buffer solution (PBS) (pH 7.4) and cucumber samples. The test was developed with a sensitive monoclonal antibody specific for ALD, generated by immunizing BALB/c mice with a well-characterized ALD – keyhole limpet hemocyanin conjugate, produced in our laboratory. Under the optimized condition, the cut-off limits of test strip for ALD were found to be 25 ng/mL in 0.01 M PBS (pH 7.4) and 100 ng/mL in cucumber samples, and the highest standard relative deviation was 9.05%. Both results were obtained within 5 min. The data indicate that the method is sensitive, rapid, and specific, so this immunochromatographic test strip has utility for the rapid high-throughput screening of the pesticide, especially in food samples. [ABSTRACT FROM AUTHOR]

Hexestrol (HES) and Diethylstilbestrol (DES) are synthetic hormones, which have been found abuse use in animal-origin food production. We developed an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and immune-chromatographic strip to detect these compounds based on monoclonal antibody. Under optimized conditions, the half-inhibition concentration (IC50) values of ic-ELISA were 0.15 µgL−1and 0.23 µgL−1for HES and DES, respectively. Spiked milk samples were analyzed. The recovery of both synthetic hormones in the milk samples was 60.48–102.19% (HES) and 89.34–100.16% (DES). In immune-chromatographic assay, the visual cutoff values at 0.5 and 1.0 µgL−1respectively for HES and DES, which allow us to detect milk samples of a concentration low to 10 µgL−1for HES and 15 µgL−1for DES. [ABSTRACT FROM AUTHOR]

Diclofenac (DIC) is often mixed into health products by unscrupulous merchants to claim antirheumatic effects. In this study, A highly sensitive group-selective monoclonal antibody (mAb) was prepared, and an immunochromatographic assay was developed for rapid screening of DIC, diclofenac methyl (DICA) and N-phenylanthranilic acid (PAA) in health teas and health beverages. In our quantitative analysis, the LOQs for the immunochromatographic test strip (ICS) for the detection of DIC (DICA and PAA) in health tea and health beverage were 0.17 (1.13 and 1.34) and 0.12 (0.25 and 0.53) ng/mL, respectively. This method was compared with LC-MS/MS method to detect the spiked samples, and the results were in good agreement with the LC-MS/MS, to verifying the effectiveness of the new method. Therefore, the ICS we have developed appears to be suitable for monitoring in-field residue levels of DIC, DICA and PAA in real samples. [ABSTRACT FROM AUTHOR]

A monoclonal antibody against testosterone was produced and used to construct an indirect enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay. As testosterone could not be linked to the protein directly, testosterone and methyltestosterone were first derived by using carboxymethoxylamine hemihydrochloride (CMO) to introduce a carboxyl group at the carbonyl group position. Then the resulting testosterone-3-CMO was coupled to the carrier protein to form the immunogen, using the 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) method. A cell line obtained by cell fusion secreted an antibody which showed high affinity with testosterone. Based on methyltestosterone-3-CMO-ovalbumin (OVA) as the competitive antigen, the ELISA we developed showed high sensitivity to testosterone, with IC50of 0.11 ng/mL. The results of cross-reactivity testing showed that the antibody was specific to testosterone. Based on this antibody, an immunochromatographic assay was developed and used to detect testosterone in milk samples. This method could be used as a fast and cost-effective alternative tool for screening for endocrine-disrupting compounds. [ABSTRACT FROM AUTHOR]

Difenoconazole is triazole fungicide, widely used to prevent the growth and reproduction of fungi and to control fungal diseases in fruits and vegetables. In this work, we prepared a hapten of difenoconazole and produced a highly-sensitive anti difenoconazole-monoclonal antibody (mAb) with an IC 50 of 0.64 ng/mL. Using the mAb, an immunochromatographic assay (ICA) was developed to analyze difenoconazole residues in pear and cucumber samples. The ICA exhibited LOD values of 2.60 and 2.30 ng/g for difenoconazole in pear and cucumber samples, respectively. The ICA showed average recoveries of difenoconazole ranging from 94.3% ± 3.6%–105.4% ± 1.6%, and CVs of 1.5–4.2% in cucumber and pear samples. When used to measure difenoconazole in samples, the ICA results were compatible with those detected by LC/MSMS. The results of this study support the idea that an ICA is a practical and effective tool for high-throughput and rapid analysis of difenoconazole residues in vegetables and fruits. [ABSTRACT FROM AUTHOR]

An enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic assay were constructed for the detection of lincomycin (LIN) in both milk and honey samples based on the monoclonal antibody named 5F6. The half-maximum inhibition of ELISA was 0.3 ng/mL after optimizing pH and ionic strength conditions; the limit of detection was 0.07 ng/mL. The cross-reactivity with clindamycin was 0.6%. LIN recovery in spiked milk and honey samples ranged from 84.6% to 115.6% with intra-assay coefficient variations of 1.7–25.4% and inter-assay coefficient variations of 2.7–8.9%. The detection limits were estimated as 2.1 µg/L for milk and 2.1 µg/kg for honey samples. The immunochromatographic assay revealed a LIN cut-off value of 10 ng/mL in PBS, 5 ng/mL in milk, and 120 ng/g in honey, and a visual lower detection limit of 2.5 ng/mL, 1 ng/mL and 30 ng/g in PBS, milk and honey, respectively. The immunochromatographic assay is preferred for large-scale practical application for its simpler pretreatment and satisfied sensitivity compared with ELISA assay. [ABSTRACT FROM AUTHOR]

• An immunochromatographic assay was first developed for high-throughput determination of paraquat residues in water samples. • The proposed assay provided visible limits of detection ranging from 0.25 to 1 ng/mL, and cut-off limits ranging from 1‒5 ng/mL for water samples detection without sample pretreatment. • For paraquat-spiked water samples analysis, the recoveries were between 83.15% ± 1.9% and 94.49% ± 2.45% with CVs ranging from 1.40% to 7.37%. Paraquat (PQ) poisoning is a serious threat to human health that leads to pulmonary toxicity, neurotoxicity, and inflammation. Protecting humans from PQ exposure requires the development of rapid analytical methods for on-site detection. Here, two monoclonal antibodies against PQ were generated and an immunochromatographic assay (ICA) was exploited to determine PQ concentrations in water samples. The results showed that the monoclonal antibody 1D6 exhibited higher affinity and sensitivity, with an affinity constant of 5.4 × 108 mol/L and a limit of detection as low as 0.02 ng/mL. Without sample pretreatment, the developed ICA method provided visible limits of detection ranging from 0.25 to 1 ng/mL, and cut-off limits ranging from 1 to 5 ng/mL, where average recoveries were between 83.15% ± 1.9% and 94.49% ± 2.45% with a coefficient of variation ranging from 1.40% to 7.37%. Importantly, these observations were consistent with liquid chromatography tandem mass spectrometry. These data and results suggested that the ICA method was a reliable, portable, and high-throughput method for determining PQ residues in water samples. [ABSTRACT FROM AUTHOR]

• A highly specific and sensitive anti-FPF monoclonal antibody was prepared. • The immunochromatographic assay was firstly developed for FPF rapid detection. • This method provided a vLOD of 0.1 mg/kg in grapes, blueberries, and tomatoes. • The prepared strip is a reliable tool for in-situ rapid detection of FPF. Flupyradifurone (FPF) is a neonicotinoid insecticide that effectively controls the spread of various pests. In this study, we established an immunochromatographic assay based on a highly specific and sensitive anti-FPF monoclonal antibody (mAb) to screen for FPF residues in grapes, blueberries, and tomatoes. The cut-off value for the immunochromatographic assay was 5 mg/kg for grapes and 10 mg/kg for blueberries and tomatoes. The calculated limit of detection of the immunochromatographic assay was 0.009 mg/kg, 0.033 mg/kg, and 0.040 mg/kg for grapes, blueberries, and tomatoes, respectively. The recovery rates of the immunochromatographic assay were 97.0–108.2 % in grape samples, 90.9–105.1 % in blueberry samples, and 94.0–103.7 % in tomato samples, and the detection results were highly consistent with LC-MS/MS results. Therefore, this immunochromatographic assay was an effective and rapid tool for screening for FPF in grapes, blueberries, and tomatoes. [ABSTRACT FROM AUTHOR]

• Torasemide-hapten was prepared by adding a carboxyl group on a benzene ring and ensuring adequate exposure of sulfonylureas. • Sensitive and specific monoclonal antibody against torasemide was firstly prepared. • Lateral flow immunoassay (ICA) was developed for torasemide rapid detection. • Cut-off value of ICA for slimming tablet and capsule samples was 5 ng/g. Torasemide is a new loop diuretic agent added illegally to health foods for weight loss, which can result in serious health risks for consumers. A rapid and sensitive immunochromatographic assay for detection of torasemide (ICA) based on a new monoclonal antibody (mAb) was developed. The mAb IC 50 for torasemide was 0.93 ng/mL, and the mAb did not cross-react with other analogues. In PBS, the cut-off value and limit of detection were 1 ng/mL and 0.11 ng/mL, respectively, with a linear range between 0.61 and 6.13 ng/mL. In slimming tablet and capsule samples, the cut-off value was 5 ng/g. Recoveries were 101.1% ± 1.7%–106.1% ± 1.3% in tablet samples and 101.2% ± 2.2%–109.1% ± 3.9% in capsule samples, with coefficients of variation 2.1%–3.1% and 1.8%–3.6%, respectively, consistent with existing LC-MS/MS methods. Therefore, the ICA is suitable for use in slimming tablet and capsule samples. [ABSTRACT FROM AUTHOR]

Highlight • A highly sensitive monoclonal antibody has been produced for first time. • The proposed assay has cutoff values of <20 μg/kg for Tol and 50 μg/kg for Tol sulfone when evaluated with the naked eye in 15 min. • Quantitative results were obtained with a strip scan reader, with limits of detection <2.60 μg/kg for Tol and its metabolites in real samples. • This immunoassay can be applied to the high throughput on-site determination of Tol and Tol sulfone in food and agricultural samples. Abstract In this study, a sensitive monoclonal antibody (mAb) against toltrazuril (Tol) was developed based on a novel hapten. The 50% inhibitory concentrations (IC 50) of toltrazuril and its metabolites ranged from 2.19 ng/mL to 4.21 ng/mL. Based on this mAb, a colorimetric paper-based sensor was developed for the rapid screening of Tol and its metabolites in samples. The proposed assay has cutoff values of <20 μg/kg for Tol and 50 μg/kg for Tol sulfone when evaluated with the naked eye, and the results could be obtained in 15 min. Quantitative results were obtained with a strip scan reader, with limits of detection <2.60 μg/kg for Tol and its metabolites in real samples. The sensitivity of both qualitative and quantitative detection meets the European Union requirements. Therefore, this strip assay provides a useful tool for the on-site detection and rapid initial screening of Tol and its derivatives in feed, egg, and chicken samples. [ABSTRACT FROM AUTHOR]

• A paper sensor was developed for measuring and monitoring imatinib in human serum. • The vLOD and cut-off values of the paper sensor were 2 and 20 ng/mL, respectively. • The calculated LOD value of the paper sensor was 0.068 ng/mL. • The samples from 10 patients was in good correlations with LC-MS/MS. Imatinib is the tyrosine kinase inhibitor of choice for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. However, imatinib has drawbacks such as drug resistance and significant differences in pharmacokinetics within patients. Therefore, a colloidal gold-based immunochromatographic assay (CG-IA) was developed for measuring and monitoring imatinib in human serum. An imatinib derivative containing carboxyl groups was used for the synthesis of the immunogen, and 4-(4-methyl-1-piperazinylmethyl) benzoic acid was selected as the hapten for the heterologous coating antigen. Next, a highly sensitive and specific monoclonal antibody (mAb), 2F7 was screened for the construction of a CG-IA, with an IC 50 value of 0.091 ng/mL. For the qualification of imatinib in human serum, the visual limit of detection (vLOD) and cut-off values of the CG-IA were 2 and 20 ng/mL, respectively. For quantitative detection, the calculated LOD value of the CG-IA was 0.068 ng/mL, with a linearity range of 1.004 and 23.087 ng/mL. The recovery rate of spiked serum samples was between 88.24 % and 104.75 %. In addition, the concentration of imatinib in the serum samples from 10 patients was detected by CG-IA and revealed a good correlation with those from LC-MS/MS. These results indicated that the developed gold-based paper sensor could become an effective tool for the rapid monitoring of imatinib in human serum samples. [ABSTRACT FROM AUTHOR]

• Two haptens were designed to produce highly sensitive and specific monoclonal antibodies (mAb) against carbamazepine (CBZ) and its metabolite carbamazepin-10, 11-epoxide (CBZ-EP). • An immunochromatographic assay (ICA) was developed for the determination of CBZ and CBZ-EP concentrations in serum. • This method can provide visible limits of detection ranging from 0.25 to 1 ng/mL, and cut-off limits ranging from 5 to 10 ng/mL, and takes 10 min to evaluate with the naked eye. • These observations were consistent with those obtained by ic-ELISA and liquid chromatography-mass spectrometry. In this study, haptens were designed to produce highly sensitive and specific monoclonal antibodies (mAb) against carbamazepine (CBZ) and its metabolite carbamazepine-10, 11-epoxide (CBZ-EP). According to the results of our competitive enzyme-linked immunosorbent assay (ic-ELISA), the half-maximum inhibitory concentration values for anti-CBZ and anti-CBZ-EP mAb were 0.18 and 0.59 ng/mL, respectively. An immunochromatographic assay (ICA) was developed for the determination of CBZ and CBZ-EP concentrations. This method can provide visible limits of detection ranging from 0.25 to 1 ng/mL, and cut-off limits ranging from 5 to 10 ng/mL, and takes 10 min to evaluate with the naked eye. Importantly, these observations were consistent with those obtained by ic-ELISA and liquid chromatography-mass spectrometry. The ICA assay represented a reliable, fast, and high-throughput method for the determination of CBZ and CBZ-EP in serum samples. [ABSTRACT FROM AUTHOR]

A sensitive monoclonal antibody (mAb) (1H1) against fumonisin B1 (FB1) was produced in our laboratory. A rapid, simple, and an immunochromatographic strip has been developed for the ultrasensitive detection of FB1 in corn samples. Under the optimized condition, the cut-off limits of test strips for FB1 were found to be 50 ng/mL in 0.01 M PBS and 25 ng/mL in corn samples. Results could be obtained within 5 min. The results revealed that the developed method is a rapid, sensitive, and simple tool for the detection of FB1. [ABSTRACT FROM AUTHOR]

• A novel hapten of methomyl was synthesized. • The methomyl concentration generating a 50 % inhibition rate is 49.8 ng/mL. • The cLOD of the ICA strip was 3.2 and 5.4 ng/mL in cabbage and tomato, respectively. • This is the first time that ICA has been applied to detect methomyl. In this study, a hapten of methomyl was designed and used to produce monoclonal antibodies (mAbs) against methomyl. Based on these mAbs, we developed an enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay (ICA) strip for the determination of methomyl residues. Results from the ELISA showed that mAb 1D10 exhibited higher affinity with an affinity constant of 2.76 × 1010 L/mol and higher sensitivity with a limit of detection (LOD) was 8.12 ng/mL. After optimizing the ICA, a visible limit of detection (vLOD) was found to be 100 ng/g and the cut-off value was 500 ng/g for methomyl in cabbage and tomato. The calculated LODs were 3.2 ng/g and 5.4 ng/g in cabbage and tomato, respectively. Moreover, results from the ICA were consistent with those of the ELISA in our recovery assay using spiked samples. Hence, the ICA method has a bright future and great prospects for the detection of methomyl in food samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hapten-2 was synthesized by extending the spacer arm of Hapten-1. • ICA for detection of PDM in potato and apple was developed. • The ICA exhibited a cut-off value of 200 ng/g and the visible LOD was 10 ng/g. • ICA strip coincided with those of LC–MS/MS in the analysis of samples. Pendimethalin (PDM), a dinitroaniline group herbicide, is extensively used for controlling weeds in amounts of agricultural crops. In this work, Hapten-1 and Hapten-2 were synthesized for the preparation of an anti-PDM monoclonal antibody (mAb), which was used to establish an indirect competitive ELISA. Based on the anti-PDM mAb, we developed an immunochromatographic assay (ICA) for detection of PDM in potato and apple. Under optimal conditions, the ICA exhibited a cut-off value of 200 ng/g and the visible limit of detection was 10 ng/g for apple and potato samples in qualitative detection. Analysis of quantitative detection suggested that the limit of detection were 5.4 and 3.2 ng/g in apple and potato samples, respectively. Moreover, the results obtained from the developed ICA strip were shown to coincide with those of LC–MS/MS in the analysis of apple and potato samples. In addition, the ICA exhibited excellent performance with regard to sensitivity, speed, and portability in contrast to previous determination methods for PDM. Hence, the proposed ICA strip showed superior prospects in PDM residue determination. [ABSTRACT FROM AUTHOR]

• A group-selective monoclonal antibody against the organoarsenic reagent was prepared. • Prepared a immunochromatographic five-link card for detection of 4 organo arsenic. • The half-maximal inhibitory concentration (IC 50) values were less than 5.49 ng/mL. • The detection only takes 15 min, and the LOQ of roxarsone was 0.04 ng/mL. In order to effectively control the excessive use of organic arsenic reagents in livestock and poultry products, there is an urgent need to develop a method for rapid detection of multiple organic arsenic reagents. In this study, two haptens were designed and derivatized around the structural formula of roxarsone, and a highly-sensitive group-selective mAb 3F2 was prepared, which can simultaneously detect roxarsone, 4-aminophenylarsonic acid, 2-aminophenylarsonic acid and phenylarsonic acid. We further developed a colloidal gold immunochromatographic test strip (ICS) and prepared a five-link card that can simultaneously detect four organic arsenics in chicken and pork samples. Its quantitative detection limits (LOQ) for the four compounds in chicken and pork samples were 0.06 and 0.32 ng/mL, 0.11 and 0.29 ng/mL, 0.34 and 0.99 ng/mL, and 0.88 and 1.5 ng/mL, respectively. This multi-ICS detection provides a powerful tool for the on-site detection and rapid screening of organic arsenic reagents in actual samples. [ABSTRACT FROM AUTHOR]

Etoxazole, a novel organofluorine pesticide, has been widely used against various mites in fruits and vegetables. In this study, we designed an etoxazole-hapten and produced a highly sensitive monoclonal antibody (mAb) against etoxazole with a half-maximal inhibitory concentration of 4.04 ng/mL. Based on the mAb, we developed an immunochromatographic assay (ICA) for the detection of etoxazole in orange and grape samples. In the qualitative detection, the visible limit of detection (vLOD) and cut-off value were 10 and 100 ng/g (fresh weight), respectively. In the quantitative detection, the LOD value was 2.03 ng/g (fresh weight) in orange and 2.52 ng/g (fresh weight) in grape samples. The recovery rates ranged from 94.7 ± 4.0% to 103.3 ± 3.8%, with CVs of 3.7–4.2% and 96.4 ± 3.4% to 106.1 ± 5.5%, with CVs of 3.5–5.2% for etoxazole in grape and orange samples, respectively. The ICA results were similar to those of LC-MS/MS. Therefore, our developed ICA is a rapid, sensitive, and simple tool for screening etoxazole residues in fruits and vegetables. • A novel hapten of etoxazole was synthesized. • A half-maximal inhibitory concentration is 4.04 ng/mL. • The cLODs of the ICA were 2.03 and 2.52 ng/g in orange and grape. • Good correlations of the results obtained by ICA, ELISA and LC-MS/MS. [ABSTRACT FROM AUTHOR]

• A hapten of oxadixyl was synthesized. • A half-maximal inhibitory concentration is 3.68 ng/mL. • The cLODs of the ICA were 1.45, 0.55, and 2.11 ng/mL in cucumber, tomato and wine. • Good correlations of the results obtained by ICA and LC-MS/MS. Oxadixyl is a systemic phenylamide fungicide, used to prevent and control disease caused by phytophthora and downy mildew in a variety of cash crops. In this study, a hapten of oxadixyl was designed and used to prepare a highly specific and sensitive anti-oxadixyl monoclonal antibody (mAb) with a 50% inhibition concentration of 3.68 ng/mL. An immunochromatographic assay (ICA) was developed for screening of oxadixyl residues in cucumber, tomato and wine. The ICA strip provided a visible limit of detection (vLOD) of 1 ng/g and a cut-off value of 20 ng/g in cucumbers and tomatoes and displayed a vLOD of 5 ng/mL and a cut-off value of 100 ng/mL in wine. The calculated limit of detection (cLOD) values of the ICA were 1.45 and 0.55 ng/g for cucumbers and tomatoes and 2.11 ng/mL for wine. The ICA gave recovery rates of 95.4–106.0% for cucumber samples, 96.4–99.5% for tomato samples and 93.0–97.4% for wine samples. Moreover, the test results provided by the ICA were highly consistent with those of LC/MS. These results and data indicated that the ICA was an effective and practical method for rapid and high-throughput detection of oxadixyl residues in cucumber, tomato, wine and other food samples. [ABSTRACT FROM AUTHOR]

• A novel hapten of propamocarb was synthesized. • A half-maximal inhibitory concentration is 3.241 ng/mL. • The cLOD of the LFIA strip were 1.43 and 0.44 ng/mL in cucumber and tomato. • Good correlations of the results obtained by LFIA and LC-MS/MS. Propamocarb is a carbamate fungicide used to control Phytophthora disease. Frequent and large-scale use of propamocarb means that it poses a potential threat to the health of consumers. Monoclonal antibodies against propamocarb were prepared using a hapten of propamocarb that was generated by introducing a benzene ring and a carboxyl group into the structure of propamocarb. A lateral flow immunoassay strip was developed for the detection of propamocarb in tomato and cucumber samples using the gold nanoparticle-labeled antibody. The immunoassay strip was found to provide a visible limit of detection was 5 ng/g and the cut-off value was 250 ng/g for propamocarb in food samples. For quantitative analysis, the calculated limits of detection (LODs) of the immunoassay strip were 1.43 ng/g and 0.44 ng/g in cucumber and tomato, respectively. Using the immunoassay strip, the average recoveries ranged from 95.5 ± 5.4% to 108.8 ± 6.8%, with CVs of 3.1–6.2% for the cucumber, and the average recoveries were 95.1 ± 6.5%–111.9 ± 4.2%, with CVs ranging from 3.7% to 6.8% for tomato samples. All the results demonstrated that the immunoassay strip was suitable for the detection of propamocarb in fruits and vegetables. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel hapten of pyridaben was designed. • The mAb had a 50% inhibitory concentration (IC 50) of 2.36 ng/mL. • The LFIA had cut-off values of 25 ng/g and 50 ng/g for pyridaben in cucumber and apple samples, respectively. • The LFIA was comparable to ic-ELISA and LC-MS. In this study, a novel hapten of pyridaben was designed and used in the preparation of a monoclonal antibody (mAb), which was then used in the development of a lateral flow immunoassay (LFIA). The mAb 3C2 had good sensitivity with a 50% inhibitory concentration (IC 50) of 2.36 ng/mL. The developed LFIA had good sensitivity with cut-off values of 25 and 50 ng/g for pyridaben in cucumber and apple samples, respectively. Importantly, our LFIA was comparable to other methods of detection such as indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and liquid chromatography mass spectrometry (LC-MS/MS). These results indicated that the LFIA method represents a reliable, portable, and high-throughput method for the on-site detection of pyridaben in vegetables and fruits. [ABSTRACT FROM AUTHOR]