Structure-function guided carbon dots for sugammadex sodium detection: sensing principle insight and fluorescence...

The safe, rapid, and precise monitoring of blood concentration of anesthesia-related drugs during clinical surgeries is crucial. The development of fluorescence-based analytical strategies utilizing multi-color carbon dots (CDs) offers a promising solution to this challenge. In this work, a novel fluorescent method for detecting sugammadex sodium (SUG), a clinically-used muscle relaxant antagonist with potential side effects at improper doses, was developed based on a dual-emissive CDs (D-CDs). D-CDs were synthesized from 2,3-diaminophenazine through a carbonized polymerization process that were further separated into green- and orange-emissive CDs (G-CDs and O-CDs). H₂O quenched the emission of D-CDs at 490 nm while SUG enhanced that at 570 nm, so that a pioneering fluorescent method for SUG was developed. The underlying sensing mechanism was researched at the molecular-structure-level by the structure deduction of CDs and theoretical simulation including energy level calculation and molecular docking. The structure-function-principle insights revealed a carbonization polymerization degree-mediated dual-emission of CDs and intramolecular charge transfer-induced fluorescence enhancement from pyridinic nitrogen of O-CDs to carboxyl groups in SUG. Therefore, the D-CDs-based method was implemented for detecting SUG in mineral water, pharmaceutical formulations, and rat serum samples in vitro. Furthermore, in vivo fluorescence monitoring of SUG was demonstrated using imaging of zebrafish after SUG administration. This work obtained CDs from a single hydrothermal process through the carbonization polymerization degree-modulation, offering a fresh conception for multi-emissive CDs. Meanwhile, the structure-function-principle research at the molecular-structure-level facilitated the novel strategy for SUG detection, advancing the field of rapid analysis for anesthesia-related drugs.