Table 1. Fluorescence (λ_ex = 350 nm) of CQDs versus References.

compound/AA-CQD	λem, nm	QY, %a	QY, %b
Cys	419	90 ± 5	86 ± 7
Lys	420	67 ± 3	63 ± 1
His	410	50 ± 3	48 ± 5
Ser	430	32 ± 2	30 ± 4
Gly	418	55 ± 4	52 ± 2
Pro	418	14 ± 1	13 ± 1
Phe	425	90 ± 4	85 ± 6
Asp	413	20 ± 2	19 ± 1
Leu	409	87 ± 5	83 ± 4

^aQS as a standard (QY = 54%, λ_em = 439 nm).

^bCoumarin 1 as a standard (QY = 59%; λ_em = 445 nm).