Application of a Perovskite NIR-LED with Highly Stable FAPbI₃@SiO₂ Core-Shell Nanocomposites in a SPR Sensing Platform

In recent years, the demand for detection and diagnostic methods has consistently risen due to the aging of the population and the increase in the number of patients with chronic diseases. Label-free biomedical detection techniques have emerged as indispensable instruments for diagnosing a variety of diseases. The development of label-free and highly sensitive near-infrared (NIR) biomedical detection technology has attracted considerable attention. As a label-free, swift, and cost-effective analytical technique, it has demonstrated immense potential for a wide range of applications. We successfully assembled FAPbI₃ near-infrared perovskite quantum dots (NIPQDs) into SiO₂ shells using a rapid room-temperature atmospheric synthesis method, obtaining monodisperse FAPbI₃@SiO₂ nanocomposites (NCs) with a high photoluminescence quantum yield (PLQY) of 72%. Additionally, the incorporation of hydrophobic multi-branched trioctylphosphine oxide effectively passivated the surface defects of FAPbI₃ NIPQDs and suppressed the hydrolysis rate of tetraethoxysilane, enabling the formation of a highly stable and high PLQY nanoscale-particle level within the FAPbI₃@SiO₂ core-shell structure. Notably, we successfully incorporated FAPbI₃@SiO₂ core-shell NCs onto InGaN blue chip as NIR excitation light sources for surface plasmon resonance sensing platforms, providing a novel platform for bioanalytical detection. With a detection sensitivity of 6302.5 nm/RIU, the system demonstrated high sensitivity, stability, and dependability. This achievement expands the biomedical research field’s capacity for diagnosis, monitoring, and treatment.