Electronic supplementary materials
A selective sensor for cyanide ion (CN−) based on the inner filter effect of metal
nanoparticles with photoluminescent carbon dots as the fluorophore
Jia Zhanga, Liang Donga, Shu-Hong Yua,b*
a
Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at
Microscale, Collaborative Innovation Center of Suzhou Nano Science and Technology,
Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
b
Key Laboratory of Materials Physics, and Anhui Key Laboratory of Nanomaterials and
Nanostructures, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031,
China
Fig. S1 TEM images of (a) Au NPs and (b) Ag NPs.
Fig. S2 (a) XPS survey of the carbon dots and (b) the N 1s scan. (c) FTIR spectrum of the carbon
dots. (d) Fluorescence lifetime measurement of the carbon dots.
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Fig. S3 Fluorescence responses of the carbon dots to the presence of (a) metal ions and (b) anions.
All the ions concentrations were 0.1 mM.
Fig. S4 Test about the centrifugation by getting rid of AuNP on the variation of fluorescence
emission intensity of the carbon dots to provide the reassuring support for the inner filter effect.
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Fig. S5 The decrease of absorbance of AgNP (48 µM) in buffer after gradually increasing cyanide
concentration at 0, 10, 20, 40, 60, 80, and 100 µM.
Fig. S6 TEM images of Ag NPs (48 µM) before and after the addition of CN- (50 µM) for 10 min.
After etching by cyanide, the average size of Ag NPs decreased from 10.8 nm to 4.6 nm.
Fig. S7 Effect of cyanide ion (100 µM) on the fluorescence of carbon dots solution.
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Fig. S8 Investigation on the effect of (a) carbon dots concentration, (b) etching temperature, (c)
excitation wavelength, and (d) etching time upon the emission intensity enhancement.
Fig. S9 (a) Selectivity test of the present sensor with a series of anions and (b) interference test of
the sensor with co-incubation of cyanide and different another anion. All the ions concentrations
were 0.1 mM.
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