Multiplexed Toxin Analysis Using Four Colors of Quantum Dot Fluororeagents

TLDR

Quantum dots can simplify multiplexed analysis. The study prepared CdSe–ZnS quantum dot–antibody conjugates to perform multiplexed fluoroimmunoassays. They performed sandwich immunoassays for cholera toxin, ricin, shiga-like toxin 1, and staphylococcal enterotoxin B in single microtiter wells, evaluating assay performance. They demonstrated simultaneous detection and quantitation of four toxins from a single sample using a linear equation‑based deconvolution algorithm.

Abstract

Quantum dots (QDs) have the potential to simplify the performance of multiplexed analysis. In this work, we prepared bioinorganic conjugates made with highly luminescent semiconductor nanocrystals (CdSe−ZnS core−shell QDs) and antibodies to perform multiplexed fluoroimmunoassays. Sandwich immunoassays for the detection of cholera toxin, ricin, shiga-like toxin 1, and staphylococcal enterotoxin B were performed simultaneously in single wells of a microtiter plate. Initially the assay performance for the detection of each toxin was examined. We then demonstrated the simultaneous detection of the four toxins from a single sample probed with a mixture of all four QD−antibody reagents. Using a simple linear equation-based algorithm, it was possible to deconvolute the signal from mixed toxin samples, which allowed quantitation of all four toxins simultaneously.