Ultrasensitive and simultaneous detection of 6 nonsteroidal anti-inflammatory drugs by colloidal gold strip sensor

Abstract

In this work, an oxicam group-selective monoclonal antibody against 6 nonsteroidal anti-inflammatory drugs (NSAID; meloxicam, lornoxicam, piroxicam, sudoxicam, droxicam, and tenoxicam) was prepared. Also, a spacer arm with carboxyl group was derived at the hydroxyl of meloxicam to generate the meloxicam hapten. The half-maximal inhibitory concentrations (IC 50 ) were, respectively, 0.31 ng/mL for meloxicam, 0.49 ng/mL for lornoxicam, 2.90 ng/mL for piroxicam, 1.95 ng/mL for sudoxicam, 3.08 ng/mL for droxicam, and 5.36 ng/mL for tenoxicam. A colloidal gold immunochromatographic strip based on the monoclonal antibody was developed for the detection of these 6 NSAID in milk. The results could be obtained by the naked eye in 10 min, and the cut-off values and the visual limits of detection in real samples were 5, 5, 10, 10, 25, and 25 ng/mL, and 0.25, 1, 0.5, 0.5, 1, and 1 ng/ mL, respectively. This immunochromatopgraphic strip is a suitable tool for on-site detection and screening of oxicam NSAID in milk samples.

Immunochromatographic assays for ultrasensitive and high specific determination of enrofloxacin in milk, eggs, honey, and chicken meat

“…Female BALB/c mice (SPF, age 6-8 wk, weight 20-24 g) were purchased from Vital River Laboratory Animal Technology Co. Ltd. and kept in a barrier environment at the Experimental Animal Center of Jiangnan University. Two immunogens, including ENR-1-BSA and ENR-BSA, were each used to immu-nize 5 mice by hypodermic injection in the neck and back (Peng et al, 2017;Guo et al, 2018;Lin et al, 2021). Mice were snatched softly and massaged for 2 min before immunization to reduce their tension and pain.…”

A Universal Fluorescent Immunochromatography Assay Based on Quantum Dot Nanoparticles for the Rapid Detection of Specific Antibodies against SARS-CoV-2 Nucleocapsid Protein

“…However, a series of immunosorbent methods require a long incubation time, skilled operator and supporting instruments, rendering them difficult to promote in practical on-site testing. Due to the advantages of low costs and convenience, immunochromatographic test strips are applied in multiple fields over the past decade, such as allergies [ 19 , 20 ], infectious diseases [ 21 , 22 ], environmental contaminants [ 23 ] and drugs [ 24 , 25 ]. All the above render lateral flow assay one of the most efficient immunological diagnostic methods to realize point-of-care diagnosis and detect previous or ongoing infections.…”

“…Quantum dots (QDs), as compelling semiconductor nanocrystal fluorophores, have been observed in recent years due to their unique optical property of obtaining high quantum yields, broad absorbance peaks, narrow symmetrical emission peaks, stability against photobleaching and high signal-to-noise ratio [ 19 , 20 ]. Moreover, many modification strategies, typified by core–shell structures [ 21 , 22 ] and inorganic carrier-based multilayer nanobeads, were used to improve the fluorescent properties of QDs [ 23 , 24 ]. A number of immunochromatography assays based on QDs labeling were developed, targeting multiplex biological macromolecules [ 25 ], disease-associated genes [ 26 ] and toxins [ 27 , 28 ].…”

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

“…The ICA strip was developed based on the strategy of competitive binding of coating antigens and target analytes to the antibody. [40][41][42] As shown in Fig. 2(b), to perform the assay, sample solution (100 µL) was added to the sample well of the ICA lying horizontally on a flat surface, and it flowed through the conjugate pad and the NC membrane to the absorbent pad under capillary action.…”