Bottom-Up Absorptive and Stretchable Plasmonic Tape for Field-Deployable In Vivo Fruit Safety Surveillance

Food safety surveillance for fresh produce requires analytical tools that operate directly on wet, curved plant and fruit surfaces, yet gold-standard methods and flexible surface-enhanced Raman scattering (SERS) substrates are often destructive or unsuitable for in vivo use. Here, we present a bottom-up absorptive ultrathin plasmonic tape-SERS-active functional elastomeric (SAFE) tape-that conforms to wet surfaces and absorbs/transports analytes to plasmonic hotspots for quantitative, multiplex in vivo SERS readouts without substrate inversion. SAFE tape swells within seconds and achieves detection limits of 1 nM for pesticides and 1 μM for plant hormones, while maintaining high signal uniformity, mechanical durability, and long-term stability. Predictive models accurately quantify mixtures across a broad range (1 μM to 1 mM). The tape also detects Penicillium spp. up to two days before visible symptoms and enables real-time monitoring of pesticide and preservative degradation during growth and storage, providing a low-cost, field-deployable platform for food safety monitoring.