Integrative Biosensing Nanoplasmonic Array for Real-Time Spatiotemporal Imaging of Protein Secretion in Cell-to-Cell Communication.

Protein secretion plays a crucial role in cell-to-cell communication, tissue homeostasis, and disease progression. Mapping secretomes from paired cells provides valuable insights into their interactions; however, existing approaches yield only semi-quantitative, endpoint data, lacking real-time and quantitative resolution. Herein, real-time spatiotemporal imaging of extracellular secretions from individual cells using a high-throughput integrative biosensing nanoplasmonic array (iBNA) within microfluidics is presented. The self-assembled iBNA, composed of precisely arranged gold nanostructures functionalized with aptamer receptors, enhances plasmonic resonance and significantly improves the spatiotemporal resolution and specificity of interleukin-6 (IL-6) imaging, surpassing conventional techniques. The iBNA's molecular recognition mechanism exploits biomolecular surface binding-induced localized plasmonic resonance shifts, correlating with cytokine concentration and enabling optoelectronic detection of transmitted light. Using iBNA, spatiotemporal resolution images of polarized cytokine-mediated cell-to-cell communication between Jurkat T cells and CD4+ T cells, which are essential to immune responses, are achieved. This transformative platform provides unprecedented insights into the spatiotemporal dynamics of protein secretion, offering significant potential for immunological research, cellular biology, and diagnostic applications in infectious diseases.