ABSTRACT:Point-of-carediagnostics for pathogen detectionare crucial for informed clinical pretreatment strategies, rendering the emergence of electro-fluidic systems increasingly attractive. However, both optical and electrical sensing strategies still face challenges in achieving high sensitivity and specificity.Herein,we present a facile and general approach for effectively integrating an electro-fluidic device that enables optical-electrical dual-mode gradient analysis of bacterial populations, mediated by a 2 lactobionamidoethyl methacrylate (SLM)-functionalized chitosan film (CS).Notably, this rational lysynthesized CS@SLM exhibits robust interfacial monolayer adsorption performance, serving as a versatile sensing platform for specific bacterial recognition, uniform capture, and rapid accumulation of Pseudomonas aeruginosa. Furthermore, the biointerface demonstrates distinct concentration-dependent adsorption behavior, particularly in diluted bacterial solutions, achieving remarkably high removal efficiencies (78.3−100%)while facilitating bacterial detection at ultralow concentrations (≤10-1CFU/mL, 0−10min). These characteristics enable the creation of a pronounced concentration gradient through subsequent diffusion processes in microfluidic channels, allowing for differential analysis of bacterial populations with thousands of fold enhancement in signal variation. Importantly, the surface-immobilized bacteria retain their bioactivities and can be effectively integrated with electrodes via the engineered biointerface, highlighting significant potential for electro-fluidic multimodal sensing systems.Collectively, this general strategy and versatile biointerface provide new insights into designing advanced electro-fluidic devices for precise bacterial density control and effective infection management.
