Formation of porous Cu hydroxy double salts nanoflowers

derived from metal-organic frameworks with efficient

peroxidase-like activity for label-free detection of glucose

Ali Lia,†, Xijiao Mub,‡, Tianrong Lia, Huang Wena, Wanchong Lic, Yuee Li*,b, Baodui Wang*,a

†State Key Laboratory of Applied Organic Chemistry Lanzhou University and Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou 730000, China.‡ School of Information Science and Engineering, Lanzhou University, Lanzhou 730000, China. §Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.

Calculation of Km and v.The Michaelis–Menten equation describes the relationship between the rates of substrate conversion by an enzyme and the concentration of the substrate. The Michaelis–Menten constant was calculated using the Lineweaver–Burk plot: v=Vmax · [S] / (Km + [S]), where v is the initial velocity, Vmax is the maximum rate of conversion, [S] is the substrate concentration, and Km is the Michaelis constant which is equivalent to the substrate concentration at which the rate of conversion is half of Vmax and denotes the affinity of the enzymefor the substrate.

Figure S1. SEM image of MOF-5-L and their average thickness is about 150 nm.

Electronic Supplementary Material (ESI) for Nanoscale.This journal is © The Royal Society of Chemistry 2018

Figure S2. XRD spectra of MOF-5-L.

Figure S3. XRD spectra of [Cu2(OH)3](OAc)·H2O.

Figure S4. SEM images of Cu HDSs nanoflowers (a) their size distribution (inset) as indicated their distribution are around 550 nm, and (b) their thickness distribution (inset) as indicated their distribution are about 12 nm.

Figure S5. TEM image of Cu HDSs mesoporous nanoflowers (left) and each porous nanoflake is made up of a lot of nanoparticles, and their nanoparticles size distribution (right) as indicated. Their nanoparticles size distribution are about 2-5 nm.

Figure S6. EDX spectra of Cu HDSs

Figure S7. Typical XPS high-resolution scans spectra of Cu HDSs nanoflowers for (a) C1s; (b) O1s; (c) Cu2p.

Figure S8. Thermogravimetric (TG) curves of the Cu HDSs in flowing N2 with a heating rate of 10 0C·min-1.

Figure S9. SEM images of the synthesis of Cu HDSs with different solvents. (a) H2O; (b) Ethanol: H2O=1:2; (c) Ethanol: H2O=2:1.

Figure S10. SEM images of the synthesis of Cu HDSs with different mole ratios MOF-5-L to Cu2+: (a) 2:1; (b) 1:1; (c) 1:1.5; (d) 1:2; (e) 1:3; (f) 1:4; (g) 1:5; (h) 1:6; (i) 1:7.

Figure S11. SEM images of the synthesis of Cu HDSs with different Cu salts. (a) CuCl; (b) CuSO4; (c) Cu(NO3)2.

Figure S12. SEM images of the synthesis of Cu HDSs with different acetates. (a) Co(OAc)2; (b) Ni(OAc)2; (c) Zn(OAc)2; (d) Mn(OAc)2; (e) Fe(OAc)2.

Figure S13. SEM images of the synthesis of Cu HDSs with different methods. (a) standing; (b) stirring; (c) heating; (d) ultrasound.

Figure S14. Dependence of the Cu HDSs peroxidase-like activity on (a) temperature; (b) pH; (c) Cu HDSs concentration; (d) TMB concentration and (e) H2O2 concentration. (a)Experiments were carried out using 50 μg/mL Cu HDSs in 2 mL 0.05 M NaAc buffer (pH 4.0) with 160 μM TMB and 1.25 mM H2O2 at 40 0C were incubated in different temperature (20-80 ℃) for 20 min. (b) 50 μg/mL Cu HDSs in 2 mL 0.05 M NaAc buffer (pH 2-8) with 160 μM TMB and 1.25 mM H2O2 at 40 0C for 20min. (c) The peroxidase activity was determined using the Cu HDSs concentration ranging from 0 to 100 μg/mL, 2 mL 0.05 M pH 4.0 NaAc buffer, 160 μM TMB and 1.25 mM H2O2 were added to the reaction. (d) Various concentrations of TMB were incubated in 2 mL 0.05M pH 4.0 NaAc buffer at 40 0C for 20 min with 1.25 mM and 50 μg/mL Cu HDSs. (e) Various concentrations of H2O2 were incubated in 2 mL 0.05 M NaAc buffer (pH 4.0) at 40 0C for 20 min with 160 μM TMB and 50 μg/mL Cu HDSs.

Figure S15. Typical absorption spectra of the different solution, Cu2+ (black line) and Cu HDSs (red line) at the same Cu2+ ion concentration.

Figure S16. A dose-response curve for H2O2 detection using 50 μg·mL-1 Cu HDSs as an artificial enzyme. Inset: linear calibration plot for H2O2 in 0.05M NaAc buffer pH 4.0 at 40 0C incubation 20 min.

Table S1. Results of the determination of glucose in the serum.