Comparison of the performances of the CDs prepared in this study and those reported in the literature for the Cr(vi) detection.

Probe	Synthesis method	Solvent	Linear range (μM)	LODs (μM)	QY (%)	Ref.
Co(ii)-CDs	Solvothermal	Ethanol	5–125	1.17	6.2	51
N, S-CDs	Hydrothermal	Water	1–80	0.86	39.7	52
Amino-CDs	Hydrothermal	Water	0.25–25	0.14	49.5	53
N, S-CDs	Hydrothermal	Juice	1–40	0.52	18.7	54
N, S-CDs	Hydrothermal	Water	1–10	0.2	Not given	36
N, S-CDs	Microwave	Water	0.35–126	0.11	54.8	29
CDs	Microwave	Water	0.05–10	0.015	20.1	55
N-CDs	Microwave	Solvent free	1–100	0.12	38.88	This work