Supporting Information
Bio-inspired Porous Antenna-like Nanocube/Nanowire Heterostructure
as Ultrasensitive Cellular Interfaces
Biao Kong,1,2 Jing Tang,1 Zhangxiong Wu,2 Cordelia Selomulya,2 Huanting Wang,2 Jing Wei,2
Yongcheng Wang,1 Gengfeng Zheng,1* and Dongyuan Zhao1,2*
1
Department of Chemistry, Laboratory of Advanced Materials, Shanghai Key Laboratory of Molecular
Catalysis and Innovative Materials, Fudan University, Shanghai 200433, P. R. China
2
Department of Chemical Engineering, Monash University, Wellington Road, Clayton, VIC 3800,
Australia
*Corresponding authors: Dongyuan Zhao, Gengfeng Zheng,
Email addresses: dyzhao@fudan.edu.cn (D.Z); gfzheng@fudan.edu.cn (G.Z)
EXPERIMENTAL SECTION
Apparatus and Measurements: The absorption spectrum was collected using a UV-vis spectrometer (PG2000
Pro, Idea Optics Co., Ltd, China). The field emission scanning electron microscopy (FESEM) images were carried out
on a FE-SEM S-4800 scanning electron microscope (Hitachi, Japan). The FETEM images and the electron diffraction Xray spectroscopy (EDX) spectra were taken with a JEM-2100F transmission electron microscope (JEM, Japan) at an
acceleration voltage of 200 kV. The photographs for 3D TiO2 NWs and biomimetic antenna-shaped structures were
taken with a Canon (EOS 450D) digital camera (Japan). Fourier transform infrared (FTIR) spectra were obtained on a
Bruker Vector 22 spectrophotometer (Shimadzu, Japan) in the range of 4000 − 500 cm−1 and recorded on solid samples
in a KBr matrix. X-ray diffraction (XRD) data were collected on a X-ray Single Crystal Diffractometer (Bruker SMART
APEX (II)-CCD, Germany) with Cu-Kα radiation (λ = 1.5418 Å) (2θ range: 10–80˚). X-ray photoelectron spectroscopy
(XPS) spectra are recorded under ultrahigh vacuum (<10-6 Pa) at a pass energy of 93.90 eV on a Perkin-Elmer PHI
5000C ESCA system equipped with a dual X-ray source by using Mg anode and a hemispherical energy analyzer. All
the energies are calibrated with contaminant carbon (C1s = 284.6 eV) as a reference. Fluorescence microscopic images
were obtained by a Nikon Eclipse TE300 Quantum inverted microscope (Nikon, Japan). CHI 660 and CHI 832
electrochemical work stations (CH Instruments) were employed in all electrochemical measurements, which were
carried out with a three-electrode electrochemical cell. Cyclic voltammetry (CV) is first carried out to investigate the
electrochemical properties of the PB-TiO2 antenna NW heterostructure in a KH2PO4/K2HPO4 buffer solution (0.05 M,
pH 6.0). The reference electrode was a KCl-saturated Ag|AgCl electrode, while the auxiliary electrode was a platinum
wire. All the experiments were performed at room temperature and the pH value was calibrated with a pH meter.
Cell culture: HEK 293T, H1299, Hela Cells were used for the cell studies. Cells were grown in DMEM (high
glucose) supplemented culture medium containing 10% fetal bovine serum, 1% streptomycin GIBCOBRL (Grand
Island, New York, USA), and 1% penicillin (37 ºC , 5% CO2). The cells were lifted with trypsin-EDTA after reaching
80 − 90% confluence and then were dispersed and diluted in DMEM (high glucose) medium. After centrifugation at
1000 rpm for 5 min, the cells were re-suspended in DMEM (high glucose) medium and the cell number was counted by
a hemocytometer method after removing the supernatant. Cells were then seeded into a Nunc Immuno OmniTray (Nalge
Nunc International, Rochester, NY) with density of approximately 1.2 × 104 cells per square centimeters. Cells were
subsequently incubated at 37 ºC in a 5% CO2 humid incubator. The number of viable cells was determined by the 3-(4,5dimethylthiazole-2-yl)-2,5-phenyltetrazolium bromide MTT assay. The cells cultured with the without biointerface
culture medium were set as controls. The absorbance was measured by testing the wavelength at 570 nm and a reference
wavelength at 630 nm to obtain sample signal (OD570 − OD630) via an ELISA plate reader using a Multiskan MK3
microplate photometer (Thermo Scientific, USA).
References:
[1] Xu, M.; Da, P.; Wu, H.; Zhao, D.; Zheng, G. Nano Lett. 2012, 12, 1503-1508.
SI Figure
Figure S1. The proposed growth mechanism of porous biomimetic antenna PB-TiO2 NW arrays
based on etching and seeds induced PB nanocrystals growth method.
Figure S2. Synthesis and characterization of PB-TiO2 heterostructure arrays with low and high
density. (a, c) Top-view SEM images of TiO2 NW arrays with different densities on FTO-coated
glass substrates. (a) low, and (c) high density. (b, d) Top-view SEM images of PB-TiO2 NWs
with (b) low, and (d) high density via an etching and seeds growth method.
Figure S3. SEM image of large area antenna-like PB-TiO2 NW arrays.
Figure S4. High-resolution transmission electron microscopy (HRTEM) image of a single PBTiO2 heterostructure.
Figure S5. SEM-EDX element analysis of antenna-like PB-TiO2 NW arrays.
Figure S6. (a, b) SEM images of typical PB seeds-modified TiO2 NW arrays.
Figure S6. (c, d) Enlarge SEM images of typical PB seeds-modified TiO2 NW arrays.
Figure S7. SEM images of typical PB-TiO2 NW arrays after removing PB nanocrystals.
Figure S8. SEM images of TiO2 NW arrays in control experiment without acid etching.
Figure S9. SEM images of control experiment of the growth with acid etching only but in the
absence of seeds. No clusters of nanocubes are formed on TiO2 NWs during the hydrothermal
process, in which only sporadic PB nanocrystals are adsorbed on the surface of TiO 2 NWs.
Figure S10. The long-term electrochemical stability of biomimetic PB-TiO2 antenna arrays (a)
The electrochemical CVs cycle of a fresh bioantenna electrode (orange curve) and a stored
bioantenna electrode (4 ºC, 180 days) (bule curve) in N2-saturated 0.05 M PBS solution (pH 6.0)
at the same scan rate of 50 mVs−1. (b) The response CVs of a fresh bioantenna electrode in the
absence (blank curve) and presence of 5 mM H2O2 (red curve), and a stored bioantenna
electrode (4 ºC, 180 days) in the absence (blue curve) and presence of 5 mM H2O2 (purple
curve) in N2-saturated 0.05 M PBS solution (pH 6.0) at a scan rate of 50 mVs−1.
Figure S11. Interface growth inhibition results for HEK 293T, H1299, HeLa cells treated with
low, median, and high density antenna PB-TiO2 NW arrays after 12-108 h incubation.
Figure S12. Interface growth inhibition results for HEK 293T, H1299, HeLa cells treated with
antenna PB-TiO2 NW arrays derived from various growth time TiO2 NWs arrays substrates after
12-108 h incubation.
Figure S13. Interface growth inhibition results for HEK 293T, H1299, HeLa cells treated with
various growth time biomimetic antenna PB-TiO2 NW arrays after 12-108 h incubation.
Figure S14. Water contact angle measurements of the TiO2 NW arrays and biomimetic antenna
PB-TiO2 NW arrays.
Table S1. Analytical Performance of the 3D H2O2 Recognition and Sensing Based on
Biomimetic Antenna PB-TiO2 NW Arrays
Nanoelectrode
BioInterfaces
Biomimetic
TiPB NWs
Cyt.c/TiO2 nanoneedles
Cyt.c /Nanoporous Au
Cyt.c /Au-NR
Cyt.c /Au/CP
Cyt.c /Au/Chit
HRP/Clay/Chit/Au
HRP/Au/TiO2
Hb/CMC-TiO2 nanotubes
Mb/titanate nanotubes
Mb/titanate nanosheets
HRP/TiO2 nanoparticles
HRP/Th-TiO2 nanotubes
HRP-TiO2 sol-gel
AP(mV)
LR (μm)
LOD (μm)
Reference
-50
(0.0 V vs Ag|AgCl)
-45
(0.0 V vs Ag|AgCl)
-100
(0.0 V vs Ag|AgCl)
-100
(0.0 V vs Ag|AgCl)
-100
(0.0 V vs Ag|AgCl)
-250
(0.0 V vs Ag|AgCl)
-300
(0.0 V vs SCE)
-600
(0.0 V vs Ag|AgCl)
-300
(0.0 V vs SCE)
~ -290
(0.0 V vs SCE)
~ -310
(0.0 V vs SCE)
0
(0.0 V vs SCE)
-645
(0.0 V vs SCE)
-250
(0.0 V vs SCE)
0.01-5.0×104
0.02
a
0.85-2.4×104
94.6
S1
10-1.2×104
6.3
S2
50-1.5×103
3.7
S3
10-1.0×103
10
S4
8.5×102-1.3
×104
39-3.1×103
9.8
S5
9
S6
5-4×102
2
S7
4-64
4.637
S8
2-160
0.6
S9
2-160
0.6
S10
7.5-123
2.5
S11
10-3.0×103
-
S12
4-1.0×103
0.8
S13
a
The present work.
Applied Potential = AP; Linear Range = LR; Limit of Detection = LOD;
Cyt.c = Cytochrome c; Hb = Hemoglobin; Mb = Myoglobin; HRP = Horse Radish Peroxidase;
Th = thionine chloride; Chit = chitosan
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