High selectivity sensing of cobalt in HepG2 cells based on necklace model microenvironment-modulated carbon dot-improved chemiluminescence in Fenton-like system

In this work, based on electronic spinning resonance and chemiluminescence (CL) measurements, it is found that the reaction kinetics of Co(II)-triggered Fenton-like reaction is much faster than those of other transition metal ions, which facilitates the observation of the strong CL signals from Co(II). Utilizing the polymer–surfactant complexes (i.e., necklace model) to act as a novel CL microenvironment, a highly selective CL sensing system for the detection of Co(II) has been successfully fabricated based on the CL resonance energy transfer between the Fenton-like reaction and necklace model microenvironment-modulated carbon dots. Under optimized experimental conditions, this proposed CL system exhibits a stable response to Co(II) over a concentration range from 1.0 to 1000 nM with a detection limit as low as 0.67 nM. Finally, this system has been successfully used for the detection of Co(II) in HepG2 cells, and the results were agreed with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) method.

► The polymer–surfactant complexes are used for a novel CL microenvironment.
► Co(II)-triggered Fenton-like CL reaction can be discriminated from other transition metal ions.
► Necklace model microenvironment-modulated carbon dots act as CL resonance energy transfer acceptors.
► This proposed system has been successfully applied for sensing Co(II) in HepG2 cells.