Supporting Information

Cellulose Nanofibers for Magnetically-separable

and Highly Loaded Enzyme Immobilization

Hwa Heon Je1,†, Sora Noh2,†, Sung-Gil Hong2, Youngjun Ju2, Jungbae Kim2,3,*, Dong Soo

Hwang1,4,*

1 Division of Integrative Bioscience and Biotechnology, Pohang University of Science and

Technology (POSTECH), Pohang 37673, Republic of Korea

2 Department of Chemical and Biological Engineering, Korea University, Seoul 02841,

Republic of Korea

3 Green School, Korea University, Seoul 02841, Republic of Korea

4 School of Environmental Science and Engineering, Pohang University of Science and

Technology (POSTECH), Pohang 37673, Republic of Korea

Supporting figures

Fig. S1. Conductivity titration of TEMPO-oxidation cellulose nanofibers.

Titration curve indicates the existence of weak and strong acids, which represents

carboxyl groups and added HCl [1]. As NaOH was added, the conductivity stiffly

decreased due to the consumption of strong acid. After the dissipation of strong acid,

the weak acid begins to be consumed with the conductivity curve to be maintained

nearly constant. For the usage of weak acid, 8.1 mL of NaOH (0.04 M) was added,

representing 0.324 mmol of NaOH. This suggests that 0.324 mmol of carboxylate

content was existed in CNFs (230 mg sample) [2]. In conclusion, CNFs have 1.41

mmol of carboxyl groups per g of CNFs.

Fig S2. Weight loss data of CNF hydrogel analyzed by TGA analysis.

Fig. S3. Pictures of cellulose nanofiber hydrogels under the various concentrations of CNFs

in an aqueous buffer (100 mM PB, pH 7.8).

Fig. S4. Pictures of CA, EC, EPC and Mag-EPC using two different concentration of CNFs:

10 mg/ml and 2 mg/ml CNFs.

Fig. S5. Activities of Mag-EPC using two different concentration of CNFs.

References

[1] J. Araki, M. Wada, S. Kuga, Steric Stabilization of a Cellulose Microcrystal Suspension by

Poly(Ethylene Glycol) Grafting, Langmuir 17 (2001) 21-27.

[2] K. Benhamou, A. Dufresne, A. Magnin, G. Mortha, H. Kaddami, Control of Size and Viscoelastic

Properties of Nanofibrillated Cellulose from Palm Tree by Varying the TEMPO-Mediated Oxidation

Time, Carbohydr. Polym. 99 (2014) 74-83.