Flow-Through Multiplex Bioassays Using Micropore-Confined Bipolar Electrochemiluminescence and Structural Color-Coded Conductive Microbeads.

Multiplex electrochemiluminescence (ECL) bioassays in continuous flow require reliable target identification and event-resolved signal assignment within the same detection process. Here, we report a flow-through, micropore-confined bipolar electrochemiluminescence (BE-ECL) platform that uses structurally color-coded photonic amorphous conductive microbeads (PACMs) as mobile bipolar electrodes. The PACMs provide visually decodable identities and generate localized ECL at their poles, enabling simultaneous detection of CEA, CA125, and AFP. Micropore confinement concentrates the electric field in the detection region, and bead polarization further enhances local ECL generation under reduced driving voltages. A serpentine microfluidic injection module separates beads before detection, allowing decoded structural-color sequences to be matched to synchronous current perturbations and ECL peaks during continuous flow. The platform achieved sensitive, selective, and reproducible multiplex detection with low background. This work provides a practical strategy for encoded suspension-array ECL bioassays by integrating structural-color coding, micropore-confined BE-ECL, and flow-through bead analysis.