Table 1 Characteristics of the CQDs synthesized from various precursors

CQDs yields

40 mg/500 g

1.5 mg/500 g

2.5 mg/500 g

6 mg/500 g

4 mg/500 g

Size distribution

2–6 nm

2–8 nm

2–9 nm

Unobvious granularity

2–7 nm

Mean size

3.1 nm

4.4 nm

4.3 nm

Unobvious granularity

3.6 nm

Fluorescence quantum yields

6.2%

0.9%

1.3%

0.6%

1.1%

Minimum detectable concentrations

2.0 ng/L

220 ng/L

170 ng/L

180 ng/L

150 ng/L