Smartphone Camera‐Driven Phosphorescence Imaging Technology: Exploration of Multiplexing and Encoding Techniques

ABSTRACT Phosphorescence imaging technology has become a powerful analytical tool for single‐particle detection in biomedical diagnostics and environmental monitoring. However, the widespread adoption of traditional phosphorescence imaging systems has been hindered by the reliance on bulky and expensive optical components. Here, we propose a smartphone‐based phosphorescence imaging (Smartphone‐Based Phosphorescence Imaging, SBPI) platform that overcomes these limitations by integrating phosphorescent carbon dots (CDs@SiO 2 ) with innovative mobile technology. Our system utilizes sodium alginate microspheres functionalized with a CDs@SiO 2 ‐fluorescent dye component (FS/R6G/RB dye) and achieves multicolor encoding through precise control of SiO 2 shell thickness and dye composition, enabling tunable emission lifetimes (2.5‐1442.4 ms) and wavelengths (440‐580 nm). The SBPI platform demonstrates excellent performance in microfluidic flow imaging, capturing high‐fidelity multicolor phosphorescence signals and significantly reducing background interference. By utilizing smartphone camera functionality and optimized video processing algorithms, we achieve color multiplexing capabilities for five different phosphorescent features. This work establishes a new paradigm for portable optical sensing, with immediate applications in on‐the‐spot diagnostics, environmental monitoring, and high‐throughput screening. The modular design of the technology and its compatibility with existing microfluidic platforms open up a new development path for the advancement of portable phosphorescence sensing technology.