How to Improve Sensitivity of Sandwich Lateral Flow Immunoassay for Corpuscular Antigens on the Example of Potato Virus Y?

Abstract

A simple approach was proposed to decrease the detection limit of sandwich lateral flow immunoassay (LFIA) by changing the conditions for binding between a polyvalent antigen and a conjugate of gold nanoparticles (GNPs) with antibodies. In this study, the potato virus Y (PVY) was used as the polyvalent antigen, which affects economically important plants in the Solanaceae family. The obtained polyclonal antibodies that are specific to PVY were characterized using a sandwich enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR). For LFIA, the antibodies were conjugated with GNPs with a diameter of 17.4 ± 1.0 nm. We conducted LFIAs using GNP conjugates in a dried state on the test strip and after pre-incubation with a sample. Pre-incubating the GNP conjugates and sample for 30 s was found to decrease the detection limit by 60-fold from 330 ng∙mL−1 to 5.4 ng∙mL−1 in comparison with conventional LFIA. The developed method was successfully tested for its ability to detect PVY in infected and uninfected potato leaves. The quantitative results of the proposed LFIA with pre-incubation were confirmed by ELISA, and resulted in a correlation coefficient of 0.891. The proposed approach is rapid, simple, and preserves the main advantages of LFIA as a non-laboratory diagnostic method.

Enhancing the Sensitivity of Lateral Flow Immunoassay by Magnetic Enrichment Using Multifunctional Nanocomposite Probes

“…Although it is a quite a rough comparison of our LFIA in combination with magnetic enrichment with ELISA, the detection sensitivity of our method for φ ≥ 10 is comparable with or even better than that of ELISA because the LOD of ELISA is approximately one order of magnitude lower than that of LFIA in a variety of applications, including forensic identification, 53 clinical diagnosis, 54 and food inspection. 55,56 In addition, the overall time required to obtain a test result for ELISA is typically ca. 3 h or longer, while our method would require less than 1 h to obtain the result for φ = 10 if both the antigen−antibody binding reaction and magnetic enrichment times were successfully decreased by the methods described above.…”

Development of a Lateral Flow Highway: Ultra-Rapid Multitracking Immunosensor for Cardiac Markers

“…In the proposed format, the detected complexes are formed after the sample has rapidly moved along the tracks on the working membrane between neighboring zones, which are only 2 mm apart. Several immunochromatographic tests that exclude the conjugate pad have been reported [13][14][15]. In these assays, the conjugate is preincubated with the sample beyond the test strip.…”

A review of recent advances in plant-pathogen detection systems

“…The immunochromatographic assay also provided a rapid visual detection within 10 min. Similar to this, a quick method for lowering the lateral flow immunoassay's (LFIA) LOD for detecting potato virus Y in infected and uninfected potato leaves was suggested ( Razo et al., 2018 ). The strategy comprised the binding of a GNP coupled with antibodies and a polyvalent antigen.…”

“… – Shojaei et al. (2016) Lateral Flow Immuno Assay Potato virus Y 330 ng/mL to 5.4 ng/mL Field samples 15 min Razo et al. (2018) Stone fruit and almond infective bacteria 10 4 CFU/mL naturally infected plants 15 min López-Soriano et al.…”