Microbial-Modified Organosilica-Based Dual-Mode Fluorescent Probe for Zn²⁺ and pH Sensing with Potential Application in Gut Immunity Modulation

Crohn's disease (CD) involves chronic intestinal inflammation, often accompanied by abnormal zinc ion (Zn²⁺) homeostasis. Herein, we developed a multifunctional nanoplatform-1-DASA-ATPMS@2@Rg3-that integrates ginsenoside Rg3 with a DASA-modified silica-based composite for ratiometric Zn²⁺ sensing and anti-inflammatory therapy. The nanocomposite exhibited a distinct ratiometric fluorescence response to Zn²⁺, with a strong linear correlation (R² = 0.9969) between the intensity ratio (I₅₀₀/I₆₇₂) and Zn²⁺ concentration over 0-200 µM, enabling accurate quantification. Time-resolved fluorescence and zeta potential analyses confirmed Zn²⁺-induced coordination and electrostatic interactions, contributing to signal amplification. Additionally, the pH-dependent optical properties further support its adaptability to inflamed gut environments. This dual-functional nanoplatform not only enables precise Zn²⁺ monitoring-a crucial marker in CD progression-but also offers therapeutic benefits via Rg3-mediated immunomodulation, presenting a promising strategy for real-time inflammation sensing and intervention in CD.

Colloidal stability; Crohn’s disease; Fluorescence sensing; Microbial; Ratiometric sensing.