Goat Anti-mouse Antibody Research Articles

Competitive electrochemical immunosensor for maduramicin detection by multiple signal amplification strategy via hemin@Fe-MIL-88NH2/AuPt

Maduramicin (MD) is a type of monoglycoside polyether ionophore antibiotic that can effectively treat coccidiosis and facilitate animal growth. However, its extensive and excessive use brings potential risk to human health. Herein, an electrochemical immunosensor based on indirect competitive format was fabricated for analysis of MD residue in eggs by a multiple signal amplification system. Initially, Au nanoparticles were deposited onto glassy carbon electrode surface to load the coating antigen MD-BSA and to improve conductivity. Then the signal amplification platform was constructed by encapsulating hemin into Fe-MIL-88 NH2 metal-organic frameworks (hemin@MOFs), and then the obtained composites were decorated with AuPt nanoparticles. The synthesized hemin@MOFs/AuPt was not only used as a signal amplification mediator, but also utilized as a carrier for immobilization of horseradish peroxidase-conjugated affinipure goat anti-mouse antibody (Ab2-HRP) and horseradish peroxidase (HRP). The constructed hemin@MOFs/AuPt-Ab2-HRP bioconjugates could effectively amplify the current signal since hemin@MOFs, AuPt and HRP all exhibited high catalytic activity towards the hydrogen peroxide. Moreover, the established immunosensor showed high sensitivity and stability during the detection procedure. With the synergistic catalytic effect of hemin@MOFs, AuPt and HRP, a wide detection range of 0.1–50 ng mL−1 and a low detection limit of 0.045 ng mL−1 were achieved (S/N = 3), respectively. Ultimately, the developed method displayed excellent performance in practical applications, providing a promising probability to detect other veterinary drug residues to guarantee food safety.

CAR T‐cells' Interaction with Artificial Antigen Presenting Cell Surface

Adoptive Cell Transfer (ACT) using Chimeric Antigen Receptor (CAR) T-cells shows promising results in treating metastatic melanoma and B cell malignancies. However, the detailed mechanism of CAR T-cell's interaction with tumors is still not well-understood. In this work, we created an artificial antigen presenting cell (APC) surface for 2nd generation (CD3 and CD28 signaling domains) CD19 and GD2 CAR T-cells and studied the interaction of CAR T-cells in terms of synapse formation. We created circular patterns of antibodies against CAR T-cells using micro-contact printing and measured the level of activation and degranulation in both CAR T-cells by quantifying the intensity of the phosphorylated CD3ζ chain (p-CD3ζ) and the Lysosome-Associated Membrane Protein 1 (LAMP-1) respectively. The results show that we can study the interaction of CAR T cell with APC surface in a reproducible manner and that different CAR T cells have a different level of activation and degranulation. Our findings suggest that the artificial APC allows for quantitative measurement of effectiveness for different CAR T cells with controlled APC density. Support or Funding Information This work was supported by the National Science Foundation through the Early-concept Grants for Exploratory Research (EAGER) (Award number: 1649243) and was performed in part at the Joint School of Nanoscience and Nanoengineering, a member of the Southeastern Nanotechnology Infrastructure Corridor (SENIC) and National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (Grant ECCS-1542174). The figure shows the interaction of GD2 CAR T-cell with 5 μm micropatterns of 1A7 (target). The aggregation of the phosphorylated CD3 zeta chain (p-CD3ζ) at the contact with the micropattern is clear. Micropatterns of 1A7 are labeled with Alexa Fluor 568 Goat anti-mouse secondary antibody and p-CD3ζ is labeled with Alexa Fluor 488 primary antibody. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

An innovative immunochromatography assay for highly sensitive detection of 17β-estradiol based on an indirect probe strategy

Ultrasensitive and fast screening of small molecule contaminants by immunochromatography assay (ICA) is still challenging in field conditions. Here, a novel indirect probe based ICA (ipICA) for highly sensitive detection of 17β-estradiol (E2) was introduced. The strategy was achieved using carboxyl modified Fe3O4 magnetic nanoparticles (MNPs) to label goat anti-mouse antibody (GAMA). The free anti-E2 monoclonal antibody (mAb) rather than labeled mAb was adopted to capture E2 molecules. For comparison, MNPs-based traditional and dual-probe ICAs were also prepared. This strip sensor demonstrated higher sensitivity, with a lowest visible detection limit of 0.2 ng mL−1, which was 5 and 2 times better than that of the MNPs-based traditional strip and dual-probe strip, respectively. The outstanding performance of this novel sensor mainly benefited from the decreased amount of free mAb and the signal amplification of this strategy. Additionally, this method was successfully applied in the detection of E2 in milk, prawn, fish and chicken samples. The proposed sensor exhibited acceptable accuracy for on-site detection of target analyte in food safety monitoring, also has potential applications for the other small molecule contaminants.

Development of an immunochromatographic strip test for rapid detection of sodium nifurstyrenate in fish

ABSTRACT 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.

Rapid detection of iprodione in cucumber and apple using an immunochromatographic strip test

ABSTRACT In recent years, fungicides have been frequently detected in soil, water, and air because of their extensive use, with detrimental effects on the environment. Therefore, the screening of foods for iprodione (IPRO) has become mandatory. A rapid, specific and sensitive method based on an immunochromatographic strip test has been developed for the determination of IPRO residues in cucumber and apple. The antigen IPRO-ovalbumin and a goat anti-mouse IgG antibody were drawn onto a nitrocellulose membrane as the test and control lines, respectively. Under optimal conditions, the cut-off limits of the semi-quantitative strip test for IPRO was as low as 10 ng/mL in 0.01 M PBS pH 7.4, 20 ng/mL in cucumber juice, and 25 ng/mL in apple juice and the results were obtained within 5 min. Our data suggests that this immunochromatographic assay can be used for the sensitive, rapid, and specific on-site screening of IPRO in cucumber and apple.

Detection of clothianidin residues in cucumber and apple juice using lateral-flow immunochromatographic assay

ABSTRACT Clothianidin (CTA), third generation neonicotinoid insecticide that has been widely used for the long-term control of a wide variety of pests. Therefore, we developed immunochromatographic assay for the detection of CTA residues in cucumber and apple juice. The antigen HCTA-EDC-OVA and the goat anti-mouse IgG antibody were added to a nitrocellulose membrane as the test and control lines, respectively. Under optimal conditions, the cut-off limits of the semi-quantitative strip test for CTA were 1 ng/mL in 0.01 M PBS (pH 7.4), 4 ng/mL in cucumber juice, and 5 ng/mL in apple juice, and the results were obtained within 5 min. The immunochromatographic assay can be used for the sensitive, rapid, and specific on-site screening of CTA residues in cucumber and apple juice.

Determination of 3.5-dinitro-N’-(5-nitrofurfurylidene) salicylic acid hydrazide in fish using immunochromatographic strip tests

ABSTRACT The nitrofurans were recently banned from use in livestock production due to their potential carcinogenicity in humans. Therefore, the screening of foods from animal origins for nitrofurans became mandatory. A rapid, specific and sensitive method based on immunochromatographic strip test has been developed for the determination of 3.5-dinitro-N’-(5-nitrofurfurylidene) salicylic acid hydrazide (DNSH) residues in fish. Fish samples were prepared by ultrasonic bath extraction, centrifugation, filtration, drying and res-suspension. The antigen (DNSH-glutaraldehyde-ovalbumin) and a goat anti-mouse IgG antibody were drawn onto a nitrocellulose membrane as the test and control line, respectively. Under optimal conditions, the DNSH cut-off limits for the test strips were determined as 10 ng/mL in 0.01 M phosphate buffered saline and 25 ng/mL in fish samples, with results obtained within 5min. Our data suggests this immunochromatographic assay can be used for the sensitive, rapid, and specific on-site screening of DNSH in fish products.

Ultrasensitive detection of avian influenza A (H7N9) virus using surface-enhanced Raman scattering-based lateral flow immunoassay strips

The development of biosensors that are portable, low-cost, and quantitative has long been sought for rapid, on-site, and timely detection of avian influenza virus (AIV). In this study, an antibody-based Raman lateral flow immunoassay strip was developed to detect AIV H7N9. This LFIA strip used a novel core-shell structure material, AuAg4−ATP@AgNPs, as a Raman probe. An antibody specific for AIV and goat anti-mouse IgG antibody were immobilized on a nitrocellulose membrane as the test and control lines, respectively. Accumulation of antibody-virus-antibody-Raman probe complex at the test line could be visualized by the naked eye, and the Raman signal could be quantified using a portable Raman instrument. The testing process for the SERS-based LFIA strips could be completed in 20 min, which avoided the time-cost of current methods for AIV analysis. In our SERS-based biosensor, we estimated the limit of detection (LOD) for H7N9 to be 0.0018 HAU. This value is approximately three orders of magnitude more sensitive than the corresponding HA assays. When testing real sample, the results of the strip test were in accordance with those from real-time PCR testing. In conclusion, the SERS-based LFIA strip proposed in this study shows tremendous potential to detect targets quickly and sensitively using an elegantly simple method.

Epidemiology of infections caused by Chlamydophila pneumoniae in patients with chronic cough

Background: Chlamydophila pneumoniae is an important etiological agent in respiratory system infections. The aim of study was to analyze the rate of Chlamydophila pneumoniae infection in adults and children and also to determine a correlation between the presence of this pathogen and symptoms of chronic cough. Material/Methods: The material for the study included swabs from the posterior pharyngeal wall taken on an empty stomach without cleaning the mouth. The diagnostic method was indirect immunofluorescence test (IIFT), which uses two types of antibodies: monoclonal mouse antibodies, which link specifically with the antigen that is present in the tested material and goat anti-mouse antibodies linked to fluorescein isothiocyanate, providing the colour reaction with C. pneumoniae antigen. Results: In our research, 593 patients, including 319 women, 175 men, aged from 18 to 87 years and a group of 99 children aged from 2 to 17 years with symptoms of chronic cough n=432 and other respiratory manifestations n=161 were studied. In the group of studied women with cough, 28.2% (64/227) of results were positive. In the group of men with cough, 22.3% (27/121) of results were positive. In the group of children with a cough, 28.6% (24/84) of the results were positive. Conclusions: In the examined group of children and adults with a chronic cough, the C. pneumoniae antigen was detected. The frequency of detection of C. pneumoniae antigen differed depending on the age group of both children and adults with symptoms of chronic cough.

Analysis of Recombinant VP22-OCT4 Fusion Protein Subcellular Location in HepG2 Cell Culture

There are many studies ongoing about the remarkable potential of pluripotent stem cell as the future regenerative therapy. Embryonic stem cell is the only source that has been studied well for it. However, many constraints arise regarding this matter like ethical problems and risk of cell transplantation rejection. Recently, there are many research undergone in exploring new approach through reprogramming somatic cell to become induced pluripotent stem cell (iPSC). OCT4 (Octamer-binding transcription factor 4) is one of the proteins that is responsible for the self-renewal of embryonic stem cell. Therefore, this study aimed to investigate the ability of OCT4 transcription factor, with the help of VP22 (viral protein), to be localized into adult somatic cells (HepG2), which in turn could reprogram it into iPSC. In this study, HepG2 cells are isolated with VP22-OCT4 recombinant fusion protein for 1 hour and 6 hours, which then followed by isolating with mouse monoclonal IgG primary antibody against OCT4 (Ab1) and goat anti-mouse IgG secondary antibody, FITC conjugate (Ab2) respectively for the indirect immunofluorescence staining function. Confocal microscope is utilized to observe the presence of immunofluorescence. The result of the experiment showed a significant difference between the control and the experimental groups for both incubation period (p = 0.005 for 1 hour and p = 0.000 for 6 hours). Moreover, there is also a significance difference between the group of HepG2 cells with VP22-OCT4 incubated for 1 hour and 6 hours (p = 0.044). In conclusion, VP22-OCT4 recombinant protein can be translocated inside the HepG2 cells under 1 hour and 6 hours of incubation periods.

Universal and reusable hapten/antibody-mediated portable optofluidic immunosensing platform for rapid on-site detection of pathogens

A universal and reusable hapten–antibody-mediated portable optofluidic immunosensing platform (OIP) was developed for rapid on-site detection of pathogens. By using Escherichia coli O157:H7 (E. coli O157:H7) and bisphenol A-Bovine serum albumin (BPA-BSA)/anti-BPA antibody as a model pathogen and a mediated hapten–antibody, respectively, a novel immunoassay mechanism was proposed to detect pathogens. The BPA-BSA-modified immunosensor and E. coli O157:H7 were initially saturated with anti-BPA antibodies (mouse IgG) and anti-E. coli O157:H7 antibodies (mouse IgG), respectively. Then, the fluorescence-labeled secondary antibodies (goat anti-mouse IgG antibody) were incubated with E. coli O157:H7 with their antibodies. Next, the mixture was introduced into the immunosensor surface bound to the anti-BPA antibodies. A high concentration of E. coli O157:H7 in the sample reduced the number of fluorescence-labeled secondary antibodies bound to the immunosensor surface, thus resulting in the detection of low fluorescence signals. Under optimized conditions, the hapten–antibody-mediated OIP system exhibited a detection limit of 8 cfu/mL E. coli O157:H7 after concentrating 100 times by using centrifugation, and a test cycle, including prereaction, detection, and regeneration, was less than 1 h. The robustness of the hapten–carrier protein-modified immunosensor surface allowed multiple pathogen immunoassays. The proposed strategy demonstrated good recovery, precision, and accuracy through the evaluation of the spiked water samples. We expect that the new platform can be readily used for the detection of other pathogens in a variety of application fields ranging from environmental monitoring and food safety to medical diagnosis.

Development and application of a rapid semiquantitative immunochromatographic test strip to detect white spot syndrome virus

White spot syndrome virus (WSSV) is one of the most serious viral pathogens causing major economic losses to the shrimp farming industry worldwide. Rapid diagnostic test is critical for disease prevention and control. Previously we have developed a rapid immunochromatographic test strip for WSSV detection, but it is limited to the qualitative testing. In this study, a semiquantitative immunochromatographic test strip (SIT-strip) was developed for WSSV detection by observing the number of positive test lines to determine the viral load levels. To achieve semiquantitative analytical ability, three test lines were designed on NC membrane to form the test zone, on which different concentration of anti-WSSV monoclonal antibody (MAb) 4G9 in a decreasing sequence from test line (TL) I to TL-III was dispensed, instead of the traditional application of a single test line. The anti-WSSV MAb 2E6 served as colloidal gold conjugate and goat anti-mouse IgG antibody on control line was used to validate the test performance. The threshold concentrations for TL-I, -II and -III were determined to be 783 ng/ml, 3.13 μg/ml and 6.26 μg/ml of WSSV, respectively, and the visual detection limit of the SIT-strip was 783 ng/ml. The developed SIT-strip was used to detect WSSV at different time points post injection of Procambarus clarkia, the results indicated that one red band was present on TL-I at 12 h post infection (hpi) in the gills, two bands in muscle and three bands in gills and hemolymph were produced at 24 hpi although there was no death at that time, and thereafter three bands were visible in all tested tissues and dead individuals. The mortality was low from 36 to 48 hpi and increased rapidly during 48–72 hpi. Meanwhile, WSSV copy numbers were detected by real time qPCR for severity grading of infection. These results revealed that this SIT-strip could provide confirmation of viral presence and concentration levels prior to mortality, which was early enough to achieve the goal of monitoring for WSSV infection loads predictive of impending disease.

Development of a Colloidal Gold-Based Immunochromatographic Assay for the Rapid Detection of Edwardsiella Ictaluri.

Edwardsiella Ictaluri is known as the etiological agent of enteric septicaemia of channel catfish, causing heavy economic losses in the aquaculture industry. In this study, a colloidal gold-based immunochromatography assay (GICA) was developed for rapid detection of E. ictaluri. Briefly, monoclonal antibody (MAbs) and polyclonal antibody (PAbs) against E. ictaluri were prepared. Sensitivity of MAbs and PAbs to E. ictaluri was analyzed by Dot ELISA. Mouse MAb5D11 against E. ictaluri was conjugated with the 20 nm colloidal gold particles as the detector. Rabbit PAbs of E. ictaluri and goat anti-mouse IgG antibody was sprayed on nitrocellulose membranes as test line (T) and control line (C) respectively. The minimum detectable amount of this method to E. ictaluri was 5 × 106 CFU/mL. Cross reactions wouldn't occur when detecting E. tarda, Aeromonas hydrophila, V. parahaemolyticus and other several common standard strains. The result could be got in only 5 to 10 minutes. It didn't need professional technologies and testing experience. So this assay was very suitable for basic departments of aquatic product companies.

Highly sensitive furazolidone monitoring in milk by a signal amplified lateral flow assay based on magnetite nanoparticles labeled dual-probe

We presented a signal amplified lateral flow assay (LFA) based on magnetite nanoparticles (MNPs) labeled dual-probe and applied it in the high sensitive and rapid on-site detection of furazolidone metabolite of 3-amino-2-oxazolidinone (AOZ). The amplified signal benefited from high affinity between two probes of MNPs labeled murine monoclonal antibody (MNPs-MAb) and goat anti-mouse antibody (MNPs-GAMA) and was achieved by the generation of dual-probe network complex. This developed method could realize high sensitive detection of AOZ with a threshold value of 0.88 ng mL−1 and a detection limit of 0.044 ng mL−1, the sensitivity was at least 10-fold improved than that of the traditional gold nanoparticle based LFA. This facile developed assay was successfully applied for rapid detection of AOZ in milk samples. The proposed method paves a new way for on-site screening of other hazardous substances in food and can be referred in all lateral flow assays.

Distinct In Vitro T-Helper 17 Differentiation Capacity of Peripheral Naive T Cells in Rheumatoid and Psoriatic Arthritis

The T-helper 17 (Th17) cells have a prominent role in inflammation as well as in bone and join destruction in both rheumatoid and psoriatic arthritis (RA and PsA). Here, we studied Th17 cell differentiation in RA and PsA. Blood samples from healthy donors, RA and PsA patients were collected. CD45RO- (naive) and CD45RO+ (memory) T cells were isolated from peripherial blood mononuclear cell by magnetic separation. Naive T cells were stimulated with anti-CD3, anti-CD28, and goat anti-mouse IgG antibodies and treated with transforming grow factor beta, interleukin (IL)-6, IL-1β, and IL-23 cytokines and also with anti-IL-4 antibody. IL-17A and IL-22 production were measured by enzyme linked immunosorbent assay, RORC, and T-box 21 (TBX21) expression were analyzed by quantitative polymerase chain reaction and flow cytometry. C-C chemokine receptor 6 (CCR6), CCR4, and C-X-C motif chemokine receptor 3 expression were determined by flow cytometry. Cell viability was monitored by impedance-based cell analyzer (CASY-TT). RORC, TBX21, CCR6, and CCR4 expression of memory T cells of healthy individuals (but not RA or PsA patients) were increased (p < 0.01; p < 0.001; p < 0.05; p < 0.05, respectively) compared to the naive cells. Cytokine-induced IL-17A production was different in both RA and PsA patients when compared to healthy donors (p = 0.0000026 and p = 0.0001047, respectively). By contrast, significant differences in IL-22 production were observed only between RA versus healthy or RA versus PsA patients (p = 0.000006; p = 0.0013454, respectively), but not between healthy donors versus PsA patients. The naive CD4 T-lymphocytes are predisposed to differentiate into Th17 cells and the in vitro Th17 cell differentiation is profoundly altered in both RA and PsA.

Protein adsorption/desorption and antibody binding stoichiometry on silicon interferometric biosensors examined with TOF-SIMS

Time-of-flight secondary ion mass spectrometry has been employed to examine, with biomolecular discrimination, sensing arm areas (20 μm × 600 μm) of integrated onto silicon chips Mach-Zehnder interferometers aiming to optimize their biofunctionalization with regard to indirect immunochemical (competitive) detection of ochratoxin A. Sensing areas are examined after: modification with (3-aminopropyl)triethoxysilane, spotting of OTA-ovalbumin conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin, reaction with OTA-specific mouse monoclonal antibody followed by goat anti-mouse IgG secondary antibody. Component mass loadings of all proteins involved in immunodetection are determined from TOF-SIMS micro-analysis combined with ellipsometry of planar surfaces. These data show that partial desorption of surface-bound probe and blocking protein takes place upon primary immunoreaction to a degree that depends on probe concentration in spotting solution. Taking into account this desorption, apparent binding stoichiometry of both antibodies in immune complexes formed onto chip surface is determined more accurately than the respective evaluation based on real-time sensor response. In addition, mass loadings for probe and secondary antibody is observed to saturate for optimum probe concentrations. Also, principal component analysis of TOF-SIMS data could resolve both immunoreactions and biofunctionalization and discriminate surfaces prepared with optimum probe concentrations from those prepared using suboptimum ones.

An Enhanced Direct Competitive Immunoassay for the Detection of Kanamycin and Tobramycin in Milk Using Multienzyme-Particle Amplification

Kanamycin (Kan) and tobramycin (Tob) are widely found in many foods of animal origin, including milk. More rapid, simple, and sensitive methods are urgently needed to monitor antibiotic residues in milk. An enhanced direct competitive enzyme-linked immunosorbent assay (dcELISA) based on gold nanoparticles (AuNPs)/horse radish peroxidase-Kan (HRP-Kan) was developed. A monoclonal antibody (Mab) against Kan was developed by classic hybridoma technology. The Mab had higher cross-reactivity with Tob (99.07%) and no cross-reactivity with other related antibiotics (< 0.5%). A novel multienzyme probe was synthesized based on AuNPs modified using HRP-Kan. The Mab against Kan, fixed by a goat anti-mouse antibody, was competitively bound by AuNPs/HRP-Kan and Kan in samples. After optimization, the limit of detection of the enhanced dcELISA was 0.022 ng/mL, representing a fivefold improvement when compared to that of conventional dcELISA (0.13 ng/mL). The recoveries of Kan and Tob in milk samples varied from 81.0 to 121.0% and 86.4 to 123.9%, respectively. Kan or Tob was found to be present at concentrations of 0.352–0.548 ng/mL in five milk samples from local markets. The results by the enhanced ELISA and UPLC-MS/MS had good correlation. It was suggested that the enhanced dcELISA, based on AuNPs/HRP-Kan, has higher sensitivity and reliable reproducibility, and thus, this could be used to detect trace contaminants.

Rapid immunochromatographic test strip detection of mabuterol and its cross-reactivity with mapenterol

ABSTRACT The misuse of β-agonists constitutes a potential risk to public health and β-agonists has been forbidden in many countries. In this study, we describe an immunochromatographic test strip method for the rapid, sensitive, and inexpensive detection of mabuterol (MAB) and mapenterol (MAP) by cross-reactivity in pig urine. For the immunochromatographic test, the coating antigen which was obtained by conjugating the salbutamol to bovine serum albumin and a goat anti-mouse IgG antibody were drawn onto a nitrocellulose membrane as the control line and test line. The test was developed with a sensitive monoclonal antibody specific for MAB, which was generated by immunizing BALB/c mice with a well-characterized MAB- keyhole limpet haemocyanin conjugate, produced in our laboratory. Under optimized conditions, the cut-off limits of the semi-quantitative test strip for MBA and MPA were as low as 10 ng/mL in both 0.01 M PBS (pH 7.4) and pig urine. All the results were obtained within 5 min. Our data indicate that the immunochromatographic assay allows provide sensitive, rapid, and specific on-site screening for MAB and MAP.

Rapid detection of penbutolol in pig urine using an immunochromatographic test strip

ABSTRACT A rapid, simple, sensitive immunochromatographic strip test was developed to detect penbutolol (PB) in pig urine based on a sensitive and specific monoclonal antibody produced in our laboratory. The antigen (PB-ovalbumin) and a goat anti-mouse IgG antibody were drawn onto a nitrocellulose membrane as the test line and control line, respectively. Under optimised conditions, the semi-quantitative test strip detected PB at concentrations of 2.5 ng/mL in 0.01 M PBS (pH 7.4) and 0.5 ng/mL in pig urine. All results were obtained within 5 min. Our data indicate that this immunochromatographic assay can be used for the sensitive, rapid, and specific on-site screening of PB.

Development of a gold nanoparticle immunochromatographic assay for the on-site analysis of 6-benzylaminopurine residues in bean sprouts

ABSTRACT 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.