Paper-based immunoassay enabled by silver clusters embedded within zeolites

Abstract

Portable biosensing technologies are crucial for decentralized diagnostics and point-of-care applications. Conventional lateral flow assays rely on colorimetric labels, limiting sensitivity and quantification. Here, we integrate optical responsive silver cluster–zeolite composites directly functionalized with antibodies into paper-based lateral flow devices, enabling simultaneous analyte recognition and luminescent signal transduction without conjugate pads. Using human immunoglobulin G as a model analyte, the device achieves quantitative detection with high sensitivity and robustness against interfering proteins and human serum. Luminescence changes upon immunocomplex formation are captured via smartphone-based fluorescence imaging and analyzed with custom algorithms. This simplified, low-cost platform demonstrates the potential of silver cluster–zeolite composites as versatile luminescent probes for scalable, smartphone-readable, and decentralized biosensing technologies suitable for real-world diagnostics.