High-Efficiency Tetracycline Sensing and Antibacterial Properties Based on Fluorescent Silicon Quantum Dots

This investigation presents a facile hydrothermal synthesis of silicon quantum dots (SiQDs) with dual-functional capabilities for tetracycline (TC) biosensing and microbial inhibition. The developed nanomaterial demonstrated remarkable antibacterial efficacy against drug-resistant pathogens, showing enhanced resistance circumvention capability compared to conventional antibiotics. Quantitative antibacterial evaluation revealed minimum inhibitory concentration (MIC) values of 1.25 mg/mL for E. coli and 2.5 mg/mL for S. aureus, indicating species-specific antimicrobial activity. Simultaneously, the SiQDs were engineered into a blue-emissive nanoprobe for TC quantification through static quenching (SQ)-mediated fluorescence quenching. The sensor exhibited linear fluorescence quenching across 10–100 μmol/L TC concentrations, achieving an ultralow limit of detection (LOD) of 1.24 μmol/L through optimized detection parameters. This bifunctional nanomaterial demonstrates significant potential for dual-purpose applications in microbial inhibition and biochemical sensing, particularly in pharmaceutical quality control and clinical diagnostics. The integrated antibacterial-sensing platform opens up new possibilities for developing smart nanomaterials that combine environmental monitoring with therapeutic functions.