Supersensitive detection of single-histamine molecule on nanoplates by turn-on small molecule fluorescence sandwich immunoassay

Abstract

We develop a supersensitive “turn-on format” fluorescence sandwich immunoassay for detecting small single molecules. Gold nanoplate-based biotin antibodies and streptavidin–fluorophores were used instead of streptavidin–horseradish peroxidase reacting with a biotin tracer in a microplate-based competitive enzyme-linked immunosorbent assay (ELISA). Our platform showed a low detection limit of 5 zeptomolar (5 × 10^–21 M), 5.4 × 10¹⁰ times higher detection sensitivity than the conventional tune-off format ELISA.