Cost-Efficient and Ultrasensitive Hydrogel-Based Visual Point-of-Care Sensor Integrated with Surface Patterning and Strongly Emissive Carbon Dots Directly from Prunus Mume Carbonisatus

Abstract

Point-of-care (POC) sensors possess significant potential for various applications such as environmental monitoring and clinical diagnosis. However, POC sensors often encounter challenges regarding accuracy and sensitivity. Herein, we present a facile, cost-efficient and high-yield synthesis strategy of strongly blue-emitting carbon dots (CDs) from Prunus mume Carbonisatus (PMC) for fabricating surface patterned fluorescent hydrogel POC sensors with ultra-high sensitivity and accuracy. By rationally integrating Fe3+-responsive PMC-CDs with surface patterning enhanced visualization (SPEV) strategy, we achieve accurate POC detection of Fe3+ ions with a visual detection limit of 0.1 μM using the pseudo-color-assisted patterned POC sensors. Benefiting from more diverse and well-controlled visual information provided by the pseudo-color images of patterned hydrogels, the ultrasensitive and accurate visual POC detection of Fe3+ in iron supplements and human serum samples could be easily achieved without using any expensive instruments. This single emitting fluorophore-based surface patterned hydrogel sensing platform exhibits significantly improved sensitivity comparable to spectrophotometer-based techniques, while simultaneously retaining the strong convenience of naked eye readout, thus holding great promise for visual POC testing.

Keywords: point-of-care detection, surface patterning, customized pseudo-color, biomass-derived carbon dots, cost-efficient synthesis, Prunus mume Carbonisatus