Table S1: Fluorescence lifetimes of proteins in presence of ZnO nanoparticles at pH
~ 7.0 (λex =295 nm, λem =340 nm) (only the maximum concentrations of ZnO used
are shown)
Sample
1
f1
2
f2
3
(ns)
0
1.34
0.29
4.85
0.36
0.05
0.18
0.13
0.17
4.15
5.29 x 10-5
1.12
0.28
4.64
0.39
0.06
0.17
0.10
0.16
4.07
0
1.72
0.32
5.30
0.46
15.81
0.12
0.22
0.10
8.94
5.29 x 10-5
1.64
0.34
5.15
0.43
15.69
0.12
0.22
0.11
8.95
(ns)
f3
4
Conc.
of ZnO
(M)
(ns)
f4
(ns)
<>
(ns)
HMb
HRP
The fourth exponential decay: I (, t) = a1exp (-t / 1) + a2 exp (-t / 2) + a3exp (-t / 3) +
a4exp (-t / 4). fi = aii / ( j ajj).
Average fluorescence lifetime, <τ> = ∑ai τi2 / ∑ ai τi (see text)
Table S 2a: Determination of binding constants K, number of binding sites n and
the different thermodynamic parameters of HMb-ZnO complex at different
temperatures
Temperature
(K)
n
log K
K(M-1)
R2
G0 (kcal mol-1)
291
1.02
4.08
1.2 x104
0.999
-2.37
298
1.00
3.88
7.6 x103
0.999
-2.29
308
0.98
3.70
5.0 x103
0.999
-2.22
H0
(kcal mol-1)
(±0.11)
S0
(cal mol-1K-1)
(±0.24)
- 6.83
-15.22
Table S 2b: Determination of binding constants K, number of binding sites n and
the different thermodynamic parameters of HRP-ZnO complex at different
temperatures
Temperature
(K)
n
log K
K(M-1)
R2
G0 (kcal mol-1)
291
1.02
3.87
7.4 x103
0.999
-5.20
298
1.04
3.80
6.3 x103
0.999
-5.14
308
1.07
3.80
6.3 x103
0.998
-5.09
H0
(kcal mol-1)
(±0.11)
S0
(cal mol-1K-1)
(±0.24)
- 8.37
-10.83
FIG. S1: The fluorescence decay profiles associated with impulse response function
(faster decay) of HMb (concentration ~ 3x10-5 M) (λex ~ 295 nm, λem ~ 340 nm) in buffer
solution in absence and presence (two decays overlap with each other) of ZnO
nanoparticles. (χ2 ~ 1.12)
FIG. S2: The fluorescence decay profiles associated with impulse response function
(faster decay) of HRP (concentration ~ 2x10-5 M) (λex ~ 295 nm, λem ~ 340 nm) in buffer
solution in absence and presence (two decays overlap with each other) of ZnO
nanoparticles. (χ2 ~ 1.12)
308K
298K
291K
-0.6
291K
298K
308K
-0.6
log [(F0-F)/ F]
log [(F0-F)/ F]
-0.3
-0.9
-1.2
-0.9
-1.2
-1.5
-1.5
-5.2
-5.0
-4.8 -4.6
log Q
Fig. S3
-4.4
-4.2
-1.8
-5.2
-5.0
-4.8 -4.6
log Q
-4.4
Fig. S4
FIG. S3: log [(F0-F)/F] vs. log [Q] plots in case of HMb–ZnO nanomaterial complex at
different temperatures.
FIG. S4: log [(F0-F)/F] vs. log [Q] plots in case of HRP–ZnO nanomaterial complex at
different temperatures.
-4.2
(A)
(B)
(C)
(D)
(E)
(F)
(G)
(H)
(I)
(J)
Fig. S5
FIG. S5: AFM Topographic images of the (A) HMb where the scan area is 3 μm × 3 μm,
(B) HMb in 3D image view, (C) HMb- ZnO nanoparticles complex where the scan area is
3 μm × 3 μm, (D) HMb- ZnO nanoparticles complex in 3D image view, (E) HMb- ZnO
nanoparticles complex where the scan area is1 μm × 1 μm, (F) the height analysis of ZnO
nanoparticle of HMb- ZnO nanoparticles complex where the scan area is1 μm × 1 μm,
(G) HRP, (H) HRP in 3D image view, (I) HRP - ZnO nanoparticles complex, (J) HRP ZnO nanoparticles complex in 3D image view taken under tapping mode in air.