Lateral Flow Immunoassay for Visible Detection of Human Brucellosis Based on Blue Silica Nanoparticles

Abstract

Brucellosis is a highly contagious zoonosis chronic infectious disease with a strong latent capability to endanger human health and economic development via direct or indirect ways. However, the existing methods for brucellosis diagnosis are time-consuming and expensive as they require a tedious experimental procedure and a sophisticated experimental device and performance. To overcome these defects, it is truly necessary to establish a real-time, on-site, and rapid detection method for human brucellosis. Here, a lateral flow immunoassay (LFIA) with a rapid, sensitive, and alternative diagnostic procedure for human brucellosis with a high degree of accuracy was developed based on blue silica nanoparticles (SiNPs), Staphylococcal protein A (SPA), and surface Lipopolysaccharide of Brucella spp. (LPS), which can be applied for rapid and feasible detection of human brucellosis. To our knowledge, this is the first report that uses blue SiNPs as a signal probe of LFIA for the rapid diagnosis of human brucellosis. The precursor of blue SiNPs@SPA such as colorless SiNPs and blue SiNPs was synthesized at first and then coupled with SPA onto the surface of blue SiNPs by covalent bond to prepare blue SiNPs@SPA as a capture signal to catch the antibody in the brucellosis-positive serum. When SPA was combined with the antibodies in the brucellosis-positive serum, it was captured by LPS on the test line, forming an antigen–antibody sandwich structure, resulting in the T line turning blue. Finally, the results showed that it is acceptable to use blue SiNPs as visible labels of LFIA, and standard brucellosis serum (containing Brucella spp. antibody at 1,000 IU/ml) could be detected at a dilution of 10−5 and the detection limit of this method was 0.01 IU/ml. Moreover, it also demonstrated good specificity and accuracy for the detection of real human serum samples. Above all, the blue SiNPs-based LFIA that we developed provides a rapid, highly accurate, and inexpensive on-site diagnosis of human brucellosis, and shows great promise in clinical diagnostics for other diseases.

Preparation and evaluation of a lateral flow immunochromatographic nanogold diagnostic kit for brucellosis in sheep

“…This study indicates that LFIA can be used as a substitution screening test for brucellosis. The developed LFA strips could detect the Ab against Brucella in a serum sample at a minimal concentration relative to the Rose Bengal test, where the minimal amount of Ab against Brucella in the serum sample detected was 1.51.58 and 1.86 S/P in the LFA strips and Rose Bengal test, respectively; these lower cutoff values indicate a high sensitivity, which is one of the most important features of a good test [24]. In other studies on the detection of Corynebacterium pseudotuberculosis, the minimal concentration that gave positive results in LFIT was CFU/0.1 mL [25], while for, Staphylococcus aureus, the sensitivity was 106 CFU/0.1 mL [26].…”

Latest Trends in Lateral Flow Immunoassay (LFIA) Detection Labels and Conjugation Process

“…Recently, Si nanoparticles have been used for the development of a LFIA test for the detection of human brucellosis. The Si NPs were modified using 3-aminopropyl triethoxysilane (APTES), for the covalent binding of Staphylococcal protein A (SPA), after the activation with glutaraldehyde ( Ge et al, 2021 ). In another recent study, a rapid test for the detection of the prostate specific antigen (PSA) was developed using silver assembled silica nanoparticles.…”

“…Due to these properties, they have the potential to become a detection label with applications in LFIA. Lirui Ge et al (2021) reported the first use of silica nanoparticles in LFIA, achieving a detection limit of 10–5 (0.01 IU/ml) for Brucella spp. antibody detection.…”

“…More recently, due to the need to enhance LFIA performance, scientists have reported using amorphous carbon nanoparticles, blue silica nanoparticles and europium nanoparticles with good analytical sensitivity ( Zhang L. et al, 2020 ; Ge et al, 2021 ; Yin et al, 2022 ). By using the europium nanoparticles scientists were able to develop a quantitative assay for the determination of Neutrophil gelatinase-associated lipocalin (NGAL), with a detection limit as low as 0.36 ng/ml ( Yin et al, 2022 ).…”

Development of Lateral Flow Immunochromatographic Test for Rapid Detection of SARS-CoV-2 Virus Antigens in Clinical Specimens

“…The blocking was carried out by adding polyethene glycol (PEG-20,000) 1% m/v final concentration with gentle stirring for another 15 min, followed by centrifugation at 12,000 rpm for one hour. The conjugated nanogold particles were suspended in 1 mL dilution buffer containing (sucrose3% (w/v), 20 mM Tris, bovine serum albumin 1% (w/v), and sodium azide 0.02% (w/v)) and stored at 4 °C [ 18 ].…”