Gold nanoparticle-based strip sensor for multiple detection of twelve Salmonella strains with a genus-specific lipopolysaccharide antibody

Abstract

In this study, an innovative competitive immunochromatographic strip sensor was developed for rapid detection of Salmonella based on a genus-specific antilipopolysaccharide (LPS) monoclonal antibody (mAb) and the heterogeneous coating antigen of a LPS-bovine serum albumin conjugate. Gold nanoparticles labeled anti-LPS mAb specifically reacted with the conserved outer core of the Salmonella LPS in the sample and the color formed on the T line was negatively correlated with the number of Salmonella cells. The sensitivity of Ra mutant LPS (without O-specific chains but has the conserved outer core) was 25 ng mL -1 , which explained the detection of Salmonella at the genus level. Based on the gray values on the test line, the limit of detection of Salmonella was 10 3 colony-forming unit (CFU) for all twelve typical strains of Salmonella. The analysis of common Gram-negative and Gram-positive bacteria demonstrated that the strip assay was specific to Salmonella. A milk sample test showed that Salmonella at a low level (1-5 CFU mL -1 ) was detected without complex biochemical confirmation steps, sophisticated instruments and professional training.

A colloidal gold immunochromatography test strip based on a monoclonal antibody for the rapid detection of triadimefon and triadimenol in foods

“…The hybridoma cells were inoculated into the abdominal cavity of mice for ascites production. The ascites were purified by the octanoic acid-saturated ammonium sulfate method (W. Wang et al, 2016). MAbs against TDF and TDN were dialyzed at 4°C against PBS (0.01 mol/L, pH 7.4).…”

Modification of a nitrocellulose membrane with nanofibers for sensitivity enhancement in lateral flow test strips

“…Lateral-ow analysis (LFA) strips, as a typical low-cost, miniaturized, user friendly, robust, and equipment-free method, are an analysis platform that is ideally suited for point of care diagnostics, and has broad applications in many elds, including food safety, [1][2][3] water resources, [4][5][6] medical safety and body health. [7][8][9] At present, several common LFAs, such as ovulation test strips, 10 pregnancy test strips, 11,12 and urine test strips 13 are sold in hospitals and pharmacies and are successful cases of LFA commercialization. However, the limited sensitivity of LFA is still a concern and remains challenging in applications.…”

Gold immunochromatographic assay for kitasamycin and josamycin residues screening in milk and egg samples

“…Immunoassays, especially colloidal gold immunochromatographic assays (GICAs) have recently been widely applied in food safety monitoring (Li et al, 2019), such as in pesticides (Verma & Bhardwaj, 2015;Ye, Wu, Xu, Zheng, & Kuang, 2018;Zhang et al, 2019), veterinary drugs (Peng et al, 2017;Tochi et al, 2016), environmental contaminants (Xing et al, 2015), harmful microorganisms (Wang et al, 2016(Wang et al, , 2017a and food allergens (Zeng et al, 2019). Immunoassays have the advantage of being simple, rapid, time-saving and low cost.…”