Rapid and Wash-Free Time-Gated FRET Histamine Assays Using Antibodies and Aptamers

Histamine (HA) is an indicator of food freshness and quality. However, high concentrations of HA can cause food poisoning. Simple, rapid, sensitive, and specificquantification can enable efficient screening of HA in food and beverages. However,conventional assays are complicated and time-consuming, as they require multiple incubation,washing, and separation steps. Here, we demonstrate that time-gated Fo??rster resonance energytransfer (TG-FRET) between terbium (Tb) complexes and organic dyes can be implementedin both immunosensors and aptasensors for simple HA quantification using a rapid, single-step,mix-and-measure assay format. Both biosensors could quantify HA at concentrations relevant infood poisoning with limits of detection of 0.19 mu g/mL and 0.03 mu g/mL, respectively. Excellentspecificity was documented against the structurally similar food components tryptamine andL-histidine. Direct applicability of the TG-FRET assays was demonstrated by quantifying HA inspikedfish and wine samples with both excellent concentration recovery and agreement withconventional multistep enzyme-linked immunosorbent assays (ELISAs). Our results show thatthe simplicity and rapidity of TG-FRET assays do not compromise sensitivity, specificity, andreliability, and both immunosensors and aptasensors have a strong potential for their implementation in advanced food safety screening