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

Shyatesa Razo,Anatoly Zherdev,Vasily Panferov,Yuri Varitsev,Boris Dzantiev,Elena Pakina,Irina Safenkova

doi:10.3390/s18113975

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.

Highlights

Lateral flow immunoassay (LFIA) is the main tool used for non-laboratory diagnostics in many fields, including medicine, agriculture, environmental monitoring, and food quality control [1,2,3,4].LFIA is based on the use of a composite of several membranes fixed on a support
We developed the sandwich LFIA for the detection of potato virus Y (PVY) based on the pre-mixing of a gold nanoparticles (GNPs)–antibody conjugate and the sample
We first found that pre-mixing the GNP conjugate and the sample significantly decreased the detection limit of the sandwich format of LFIA

Summary

Introduction

Lateral flow immunoassay (LFIA) is the main tool used for non-laboratory diagnostics in many fields, including medicine, agriculture, environmental monitoring, and food quality control [1,2,3,4].LFIA is based on the use of a composite of several membranes fixed on a support (i.e., the test strip). Lateral flow immunoassay (LFIA) is the main tool used for non-laboratory diagnostics in many fields, including medicine, agriculture, environmental monitoring, and food quality control [1,2,3,4]. Immunoreagents (i.e., the antibodies in the test and control zones and their labeled conjugate) are provided in dry form. The immersion of one end of the test strip in the analyzed sample initiates its migration along the strip as well as the formation of a colored complex of immunoreactant and label in a certain zone of the strip [5,6]. The sequence and efficiency of the binding of the antigen with antibodies and conjugates depend on the kinetic conditions of the LFIA. The main advantage of LFIA is that it provides a rapid analysis in the absence of equipment and specially trained personnel

Objectives

Methods

Results

Conclusion