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Electronic Supplementary Information for

Antioxidant/Polyphenolic Activity Assay Based on the

Inhibition of Oxidation and Photobleaching of L-

Cysteine-Capped CdTe Quantom Dot

Bahram Hemmateenejad , Mojtaba Shamsipur , Tahereh Khosousi , Omidreza Firuzi ,and Maryam

Shanehsaz

Electronic Supplementary Material (ESI) for AnalystThis journal is © The Royal Society of Chemistry 2012

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Fig. S1 Images of vials containing QDs of different sizes. Color images of vials containing QDs of

different sizes in ambient light (top), and under UV light (bottom).

Fig. S2 Absorption and fluorescence spectra of different size QDs. Absorption spectra (left) of different

size QDs which are presented in Fig S1. Fluorescence spectra (right) of different size QDs in PBS 0.04

M (pH=7.4). [QD] = 30 nM, λexi= 360 nm. All fluorescence spectra are normalized to 1.

0

0.2

0.4

0.6

0.8

1

500 550 600 650

wavelength (nm)

FL

(a.

u)

)

0

0.2

0.4

0.6

0.8

1

350 450 550 650

Wavelength (nm)

Ab

s.

Electronic Supplementary Material (ESI) for AnalystThis journal is © The Royal Society of Chemistry 2012

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Fig. S3 The relation between inhibition percentage and concentration of NaN3. at concentrations:

1.0×10-5, 1.6×10-4, 3.3×10-4, 6.6×10-4, 1.0×10-3, 5.0×10-3, 1.0×10-2, 2.0×10-2, 4.0×10-2, 5.0×10-2,

6.0×10-2 and 8.0×10-2 M. Experimental conditions, as in Fig S2.

0

30

60

90

120

-5.5 -4.5 -3.5 -2.5 -1.5 -0.5

Log ([NaN3])

% In

hib

itio

n

y = 39.938x + 155.47R2 = 0.9907

0

30

60

90

120

-4 -3 -2 -1

Log ([NaN3])

% In

hib

itio

n

Electronic Supplementary Material (ESI) for AnalystThis journal is © The Royal Society of Chemistry 2012

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.

Fig. S4 Effect of tea samples on photobleaching of QDs. Change in fluorescence signal of QDs for

different tea samples without tea (gray curve) and with tea (black curve) (A) White tea, (B) Green tea,

(C) Red tea (D) Black tea 20 µL of each tea sample in 3.0 mL PBS 0.04 M (pH=7.4), [QD] = 30 nM,

λexi= 360 nm. All fluorescence spectra are normalized to 1.

0

0.2

0.4

0.6

0.8

1

1.2

450 550 650

Wavelength (nm)

FL (a.u.)

0

0.2

0.4

0.6

0.8

1

1.2

450 550 650

Wavelength (nm)

FL (a.u.)

0

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0.8

1

1.2

450 550 650

Wavelength (nm)

FL (a.u.)

0

0.2

0.4

0.6

0.8

1

1.2

450 550 650

Wavelength (nm)

FL (a.u.)

A B

C D

Electronic Supplementary Material (ESI) for AnalystThis journal is © The Royal Society of Chemistry 2012

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Table S1. Linear ranges for inhibition percentage versus concentration of different

antioxidant/polyphenolic compounds and related correlation coefficients.

* All experiments repeated three times and RSD for all measurements were lower than 5%.

Antioxidant Linear Equation Correlation

Coefficient (R2) Linear Range (M)

Quercetin Y=23.546 X + 205.99 0.8500 3.33×10-7-1.66×10-5

Tannic acid Y=58.645 X + 323.88 0.9995 1.66×10-5-1.66×10-4

Caffeic acid Y=67.748 X + 350.42 0.9933 1.66×10-5-1.66×10-4

Gallic acid Y=19.799 X + 153.00 0.9961 1.66×10-6-6.66×10-4

Naringine Y= 44.007 X + 229.50 0.9837 3.33×10-5-1.00×10-3

Trolox Y=23.567 X + 137.78 0.9830 3.33×10-5-3.33×10-4

Electronic Supplementary Material (ESI) for AnalystThis journal is © The Royal Society of Chemistry 2012