Inulin-Based Fluorescent Carbon Dots as Effective Probes for Rapid/Visual Detection of 3-Nitrotyrosine

Abstract

Inulin-based nitrogen-doped carbon dots (I-CDs) with a quantum yield of 28.6% were synthesized by hydrothermal method. I-CDs exhibited a narrow particle size distribution, excellent dispersibility in water, and good stability. For the first time, I-CDs were applied in the field of fluorescence sensing, and a blue fluorescence probe was developed for rapid and specific detection of the biomarker 3-nitrotyrosine (3-NT), achieving a detection limit as low as 0.323 μΜ. Furthermore, the practicality of this sensor was successfully verified via the quantitative detection of 3-NT in tap water and human urine. Notably, the first CDs-based smartphone-assisted sensing system for 3-NT was established by integrating a paper-based sensor with smartphone RGB color analysis application. The paper-based sensor showed a low LOD of 2.015×10-5 mol/L and excellent storage stability. This work provides a convenient and efficient method for on-site detection of 3-NT.

Keywords: Carbon dots, Inulin, Fluorescence sensing, 3-nitrotyrosine detection, Paper-based sensor