Electronic Supporting Information for
Homogeneous Fluorescence Resonance Energy Transfer
Immunoassay for the Determination of Zearalenone
Taihua Li,1,+ Bo Bae Kim,2,+ Won-Bo Shim,1 Ju-Young Byun,1 Duck-Hwa Chung,3 YongBeom Shin,2 Min-Gon Kim1,4,*
1
School of Physics and Chemistry, Gwangju Institute of Science & Technology (GIST), 261
Cheomdan-gwagiro, Gwangju 500-712, Korea
2
Research Center of Integrative Cellulomics, Korea Research Institute of Bioscience &
Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Korea
3
Division of Applied Life Science, Graduate School of Gyeongsang National University, Jinju
660-701, Republic of Korea
4
Advanced Photonics Research Institute, Gwangju Institute of Science & Technology (GIST),
261 Cheomdan-gwagiro, Gwangju 500-712, Korea
*Corresponding author: FAX: +82-62-715-3419;
E-mail address: mkim@gist.ac.kr
+
These authors contributed equally to this work.
A)
B)
C)
Fig S1. (A) Chemical structure of zearalenone (ZEN); (B) Absorption spectrum of 10 μg mL-1 ZEN in
methanol (red curve); (C) Fluorescence spectra of 5 μg mL-1 ZEN in methanol upon excitation at 280 and 320
nm.
Fig S2. Fluorescence excitation spectra of ZEN (5 μg mL-1) in various pH conditions with 10 mM
cetyltrimethylammonium bromide (CTAB) at emission wavelength of 450 nm. pH 4.0 and 5.0: 10 mM acetate
buffer; pH 6.0, 7.0, and 8.0: 10 mM phosphate buffer; pH 9.0: 10 mM NaHCO3 buffer.
A)
B)
C)
D)
E)
F)
Fig S3. Fluorescence spectra of ZEN, anti-ZEN antibody (anti-ZEN), and ZEN/anti-ZEN complex in pH 9.0 10
mM NaHCO3 buffer with various concentration of CTAB upon excitation at 280 nm: (A) 0 mM CTAB, (B) 0.5
mM CTAB, (C) 1 mM CTAB, (D) 2 mM CTAB, (E) 5 mM CTAB, (F) 10 mM CTAB. 100 ng mL-1 of ZEN and
20 μg mL-1 anti-ZEN were used in this analysis.
A)
B)
Fig S4. (A) Fluorescence intensities of ZEN and ZEN/anti-ZEN complex at 430 nm from Fig S3; (B) Relative
fluorescence intensities of ZEN/anti-ZEN complex (IZEN/anti-ZEN – IZEN) from (A) at 430 nm.
A)
B)
Fig S5. Fluorescence excitation spectra of ZEN, anti-ZEN, and ZEN/anti-ZEN complex with 0 mM CTAB (A)
and 0.5 mM CTAB (B) upon emission wavelength at 430 nm. 100 ng mL-1 of ZEN and 20 μg mL-1 anti-ZEN
were used in this analysis.
A)
B)
Fig S6. Plot of relative fluorescence intensities of I430 nm (A) and /I350 nm (B) from Fig 3A in the manuscript as a
function of concentration of ZEN from 0 to 1000 ng mL-1. Inset figures: Linear portion of the plot A and B.
Fluorescence spectra were recorded using excitation at 280 nm. Error bars denote standard deviation of 3
replicates each.
Table S1. LOD determination
Method
LOD
I430 nm/I350 nm
0.8 ng/mL
I350 nm
2.3 ng/mL
I430 nm
6.8 ng/mL
A)
C)
B)
D)
Fig S7. Fluorescence spectra of 0, 20, and 100 ng mL-1 ZEN with anti-IFN - (A), anti-OTA (B), and anti-ZEN
(C); 0, 20, and 100 ng mL-1 ZAN with 20 μg mL-1 anti-ZEN (D). (Excitation wavelength: 280 nm)
A)
B)
C)
D)
Fig S8. Fluorescence spectra of solutions in final containing 0, 2, 10 ng mL-1 ZEN with unspiked wheat (A),
with 20 μg mL-1 anti-ZEN (B), with spiked wheat (C) and 0, 2, 10 ng mL-1 ZEN spiked wheat samples with 20
μg mL-1 anti-ZEN (Excitation wavelength: 280 nm).