Comparison of our proposed method and the reported cases to detect VB₁₂ based on PL.

Sensor	Linear range	LOD	Ref.
Graphene oxide nanolayer	0–1.08 μM	320 nM	1 (ref. 18)
CdS	3.7–73.8 μg mL−1	5.1 μM	2 (ref. 19)
CdTe	0.7–1.8 μM	0.1 μM	3 (ref. 20)
CDs	0.3–15 μM	93 nM	This work