A dual-signal sensor for highly selective and reliable detection of rutin based on molecularly imprinted Prussian...

The reliable and accurate quantification of rutin is essential for pharmaceutical quality control, pharmacokinetic investigations, and clinical applications, owing to its broad pharmacological activities. In this study, we address this need by developing a novel dual-mode sensing platform based on a molecularly imprinted polymer-coated bimetallic Prussian blue analogue (Mn/FePBA@MIP). The Mn/FePBA@MIP analogue not only exhibits high peroxidase-like catalytic activity via its synergistic bimetallic sites but also possesses target-specific recognition capability through its surface-imprinted cavities. Upon specific rebinding of rutin, the imprinted polymer layer blocks substrate access to the catalytic sites via a gatekeeper effect, thereby quenching both the colorimetric and fluorescent signals. Under optimized conditions, the developed sensor achieves wide linear detection ranges of 6-1536 μg mL^-1 for the colorimetric mode and 6-3072 μg mL^-1 for the fluorescent mode, with corresponding detection limits of 3.98 μg mL^-1 and 1.32 μg mL^-1, respectively. For on-site applications, the sensor was integrated with a smartphone-based readout system for quantitative analysis via RGB value extraction, and successfully applied to determine rutin in traditional Chinese medicine samples with satisfactory recoveries. This work thus provides a reliable and portable dual-signal strategy for routine quality assurance of rutin-related herbal products.