Synthesis of selective fluorescent nanoMIPs via solid-phase imprinting for a homogeneous FRET assay: tryptamine...

In this study, a homogeneous fluorescence approach for detecting tryptamine (TRY) was developed by integrating fluorescent molecularly imprinted polymer nanoparticles (F-nanoMIPs) with Förster resonance energy transfer (FRET). The F-nanoMIPs were synthesized via solid-phase imprinting using TRY as a template and 2-(5-(dimethylamino)naphthalen-1-ylsulfonyloxy)ethyl methacrylate (DNS-HEMA) as a fluorescent monomer. Binding properties were evaluated through isothermal adsorption experiments, which revealed that F-nanoMIPs exhibited a high adsorption capacity (289.06 mg·g^-1) for TRY. The FRET-based detection system demonstrated rapid detection within 1 min, with a linear range of 0.678-67.842 μM (R² = 0.9946) and a low limit of detection of 0.554 μM. Cross-reactivity studies highlighted remarkable selectivity for TRY and its analogues (< 3 %). In spiked fruit samples, the recoveries for TRY ranged from 85.58 to 110.25 %. This approach combines molecular imprinting technology with FRET mechanisms to establish a cost-effective detection sensor featuring long-term stability, rapid response, and dual recognition capabilities.