Fluorescence decay rates of N-CDs in the absence and presence of different I⁻ concentrations.

	C I− (mM)	Φ FL a	τ (ns)	k r (s−1)	k nr (s−1)
N-CDs	0	18.79%	5.69	3.30 × 107	1.40 × 108
N-CDs/I−	0.45	12.36%	4.31	2.86 × 107	2.04 × 108
N-CDs/I−	8.0	5.26%	2.70	1.95 × 107	3.58 × 108

^a Φ _FL values were estimated on the basis of the slope method (Fig. S5, see ESI).