Real-Time Electrochemical Sensing Enabled by Nanoconfined Hydrogels in Solid-State Arrayed Nanochannels.

Nanochannel sensing holds great promise for chemical and biological detection. However, due to the inherent heterogeneity in pore size and distribution, the signal stability and sensitivity of arrayed-nanochannel sensing remain limited, making it difficult to use for real-time detection. Here, we report a hybrid membrane for real-time detection that is fabricated by filling functional hydrogels into macroporous anodic aluminum oxide (AAO) nanochannels, yielding a rigid-flexible composite architecture. This design utilizes the confinement effect of the AAO framework to restrict hydrogel swelling, thereby establishing stable ion transport pathways. Functional groups in the hydrogel enable the selective capture of target analytes through electrostatic interaction. The synergistic effects of localized charge enrichment and modulated mass transport not only ensure robust and efficient target binding but also establish a linear correlation between the current decay rate and analyte concentration. Consequently, our platform enables highly stable and interference-resistant detection of trace analytes in complex matrices.