Ultrasensitive biogenic amine sensor using an enhanced multiple nanoarray chip based on competitive reactions in an evanescent field

Abstract

Considering the importance of biogenic amines (BAs), such as histamine, tyramine, and putrescine, as biomarkers and the challenges in their simultaneous detection at low concentrations, a novel enhanced multiple nanoarray BA sensor was developed using a competitive reaction in an evanescent field (EF). BAs were bound to specific antibodies on different gold nanoarray islands on a multiple nanoarray sensor chip. The electromagnetic field in the EF produced fluorescence signals of BA-conjugated quantum dots with an excellent signal-to-noise ratio on the islands. Compared to conventional fluorescent dyes or plasmonic nanoparticles as detection probes, quantum dots showed improved detection sensitivity with excellent photostability. The competitive reaction in EF was simultaneously used to detect three BA molecules on the multiple nanoarray. The multiple BA sensor exhibited an excellent detection limit of 63 aM with a wide dynamic range of 100 aM–10 nM, which had a 1,000,000-fold higher sensitivity than that of previously reported methods. The proposed BA sensor was validated by high-performance liquid chromatography and enzyme-linked immunosorbent assay and was applied to identify BAs in wine samples. The results agreed with those of standard methods, showing 95 % confidence level. The combined competitive reaction and simultaneous detection of BA-conjugated quantum dots in EF on the multiple nanoarray sensor exhibited excellent enhancement of detection sensitivity. This high-throughput screening method shows highly specific labeling using promiscuous antibodies for detecting small molecules in complex matrices.