Dielectric Nanocavity Enhanced Fluorescence Emission for Ultrasensitive Wavelength-Multiplexed Detection

This study demonstrates a novel biosensing platform utilizing a dielectric nanocavity to enhance fluorescence emission for the ultrasensitive detection of biomolecules. By coupling a silver (Ag) nanocube with a distributed Bragg reflector (DBR) mirror, we achieved a substantial fluorescence enhancement reaching a maximum enhancement factor of up to 855-fold and having quasi-single molecule sensitivity. The platform was successfully applied for multiplexed detection of four different miRNA biomarkers, showcasing its ability to detect multiple targets simultaneously with high sensitivity. The simplicity, rapid speed, and small detection volume (down to 0.5 μL) of this system make it suitable for high-throughput and large-area nanocavity imaging. Our findings offer a promising solution for ultrasensitive, multiplexed biosensing with potential applications in disease diagnosis, personalized medicine, and digital molecular diagnostics.