A Fast and Sensitive Quantitative Lateral Flow Immunoassay for Cry1Ab Based on a Novel Signal Amplification Conjugate

Abstract

A novel lateral flow immunoassay (LFIA) signal amplification strategy for the detection of Cry1Ab based on amplification via a polylysine (PL) chain and biotin-streptavidin system (BSAS) is described. In this system, multiple fluorescence dyes (FL) were directly coated on the surface of PL and conjugated with antibody via the BSAS for construction of novel signal amplification (FLPL-BSAS-mAb1) conjugates, in which FL, PL and BSAS were employed to improve the sensitivity of LFIA. Compared with conventional LFIA, the sensitivity of FLPL-BSAS-mAb1-based LFIA was increased by approximately 100-fold. Quantified linearity was achieved in the value range of 0–1,000 pg/mL. The limit of detection (LOD) was reached 10 pg/mL after optimization of reaction conditions. To our knowledge, this represents one of the most sensitive LFIA for Cry1Ab yet reported. Furthermore, the detection time for this method was about 10 min. Therefore, it should be an attractive alternative compared to conventional immunoassays in routine control for Cry1Ab.

Sensitivity enhancement in lateral flow assays: a systems perspective

“…48 Chen and Wu used a biotin-functionalized antibody, biotin-functionalized polylysine scaffolds loaded with multiple fluorescent dyes, and streptavidin linkages to create a detection reagent with tens to hundreds of fluorescent dye labels. 49 These multivalent labels increased the assay sensitivity 100-fold compared to gold labels in a Cry1Ab toxin LFA. Silver nanoparticles were used to quench carbon dots in a zearalenone LFA that was ten times more sensitive than the LFA with silver nanoparticle labels alone.…”

Performance Improvement of the One-Dot Lateral Flow Immunoassay for Aflatoxin B1 by Using a Smartphone-Based Reading System

“…Particularly, some LFIAs for quantitative or semi-quantitative analysis have been developed using a reading device. As there is an increasing need for high performing LIFA in the clinical, environmental, self-diagnosis, agriculture, and food safety areas [12–16], conventional LFIA having readout errors to the naked eye is up against some major problems such as poor quantitative discrimination, and low analytical sensitivity. To make the most out of LFIA's advantages such as moderate price, rapid point-of-care diagnosis, and the absence of need of expensive equipment and skilled personnel, LFIA readers measuring the optical densities of the LFIA detection area have been developed for point-of-care applications.…”

PCB-Based Magnetometer as a Platform for Quantification of Lateral-Flow Assays

“…Despite numerous advancements in colorimetric labels, including gold nanocages [1], nanotubes [2], carbon nanoparticles [3], and cellulose nanobeads [4], among others, the sensitivity, signal range, and quantifiability of colorimetric label based LFAs remain a challenge. The use of other optical labels such as fluorescent dyes [5,6] or luminescent nanoparticles [7,8] faces various challenges due to reagent complexity, cost, and reader complexity [9].…”