Table 2. Different Quantum Dot-Based Sensing Devices for Cr⁶⁺ Detection.

sr. no.	the sensor system	linearity range	detection limit	refs
1	CQDs	0.5–200 μM	0.73 μM	(43)
2	N-CQDs	0–100 μM	2.1 μM	(39)
3	CQDs	1–20 μM	0.175 μM	(42)
4	N,S-CQDs	1–10 μM	0.2 μM	(64)
5	N,S-CQDs	1–40 μM	0.52 μM	(65)
6	B,N-CDs	0.3–500 μM	0.24 μM	(66)
7	CQDs	0–480 nM	59.6 nM	current work