Advantages of Lateral Flow Assays Based on Fluorescent Submicrospheres and Quantum Dots for Clostridium difficile Toxin B Detection

Abstract

Clostridium difficile colitis is caused by a cytotoxin produced by the anaerobic bacteria C. difficile in the epithelial cells of the large intestine, particularly C. difficile toxin B (TcdB). However, the sensitivity of currently utilized C. difficile endotoxin determination methods has been called into question, and, therefore, more accurate and convenient detection methods are needed. Our study is the first to systematically compare fluorescent submicrosphere-based and quantum-dot nanobead-based lateral fluidity measurement methods (FMs-LFA and QDNBs-LFA) with toxin B quantification in fecal samples via sandwich analysis. The limits of detection (LOD) of FMs-LFA and QDNBs-LFA in the fecal samples were 0.483 and 0.297 ng/mL, respectively. TcdB analyses of the fecal samples indicated that the results of QDNBs-LFA and FMs-LFA were consistent with those of a commercial enzyme-linked immunosorbent assay (ELISA) test kit. The sensitivity of QDNBs-LFA was highly correlated with clinical diagnoses. Therefore, quantum dot nanobeads (QDNBs) are deemed highly suitable for lateral fluidity analyses, which would facilitate the implementation of portable and rapid on-the-spot applications, such as food hygiene and safety tests and onsite medical testing.

Rapid-format recombinant antibody-based methods for the diagnosis of Clostridioides difficile infection: Recent advances and perspectives

“…This has led to the introduction of numerous antibody-based diagnostic kits so far, however, obtaining antibodies with specificity, sensitivity, and high affinity has always been a challenge facing researchers ( Hammers and Stanley, 2014 ). Recently, some studies have focused on the application of antibodies for CDI diagnosis; and further research is still being conducted in this area ( Fang et al, 2013 ; Davies et al, 2015 ; Qi et al, 2020 ). Most of the research has been done on the production of antibodies using the hybridoma technology, which has been applied successfully in numerous cases, while it has many shortcomings, such as being time-consuming and inefficient in generating antibodies toward highly-conserved antigens, self-antigens, sensitive, and toxic antigens ( Parray et al, 2020 ).…”

“…Moreover, concerning sensitivity, QDNBs-LFA showed good correlations with clinical diagnosis. Thus, the performance of QDNBs in this diagnostic system was highly applicable for designing portable and rapid on-the-spot platforms ( Qi et al, 2020b ). Overall, the use of rAbs can be suggested to increase the efficiency of these biosensors ( Sharma et al, 2016 ; Lara and Perez-Potti, 2018 ), and should not be ignored in future studies.…”

Overview of current detection methods and microRNA potential in Clostridioides difficile infection screening

“…If the toxin immunoassay result is negative, a bacterial culture will be performed[ 53 ]. In addition, new protein-based assays such as lateral flow assay are under development and may potentially yield a result in 15 min[ 54 ].…”

Application of Quantum Dots in Lateral Flow Immunoassays: Non-Communicable and Communicable Diseases

“…Quantum dots (QDs) are ideal fluorescent labels for immunoassay application. Their unique optical properties, molecular extinction coefficients, and excellent resistance to chemical and photo-degradation have advantaged them significantly over fluoro-dyes [11]. In LFA application, QDs have been used in antigen-antibody reactions to detect a variety of Advantages • Low Cost.…”