The document describes Ion Jelly, a new conducting and biocompatible material made by mixing gelatin with ionic liquids. Ion Jelly is light, flexible, thermally stable up to 180°C, and has conductivity above 10-4 S/cm. It can be adjusted to various surfaces and is environmentally friendly. Ion Jelly shows potential for applications such as biosensors and electron transfer due to its ability to immobilize proteins while maintaining their activity.

1. MATERIAL FOR SMART ELECTROCHEMICAL APPLICATIONS ION JELLY®: A TAILOR-MADE CONDUCTING Pedro Vidinha , Nuno M.T. Lourenço, Tânia Carvalho, Ana R. Brás, Teresa S. Silva, Abhik Mukhopadhyay, Crístina M. Cordas, Maria J. Romão, Madalena Dionisio, Joaquim M.S.Cabral, Luis P. Fonseca , Carlos A.M. Afonso& Susana Barreiros.

2. Ion Jelly A light, flexible conducting biopolymer - Ajustable to a great variety of surfaces Thermal stability (up to 180 ºC) Large electrochemical window Bio-compatible Condutivity above 10 -4 S.cm -1 Enviromentally friendly PT PATENT 103765 WO PATENT submited ION JELLY®: A TAILOR-MADE CONDUCTING MATERIAL FOR SMART ELECTROCHEMICAL APPLICATIONS, paper submitted

3. Ion Jelly Ionic Liquids - A re liquids made entirely of ions Organic cation and organic or inorganic anion Wide range ionic conductivity, 0.1-80 mS cm -1 Large electrochemical window ( 4-5.7 V) Thermal stability (over 300 ⁰C) Negligible vapour pressure

4. Ion Jelly Gelatin Contains in it’s structure a large number of amino-acids residues Prepared from the thermal denaturation of collagen or after an alkaline or acid pre-treatment One of the abundant biopolymers in earth Gly Gly Gly 4Hyp

5. Ion Jelly Synthesis Viscous homogeneous solution Transparent flexible films Flexible blocks Gelatin Ionic liquid Mixing above 35 ºC Room temperature water

6. Ion Jelly Synthesis Anion Polarity essential for the ion jelly synthesis Cation plays an important role – hydrogen bounding Anions and Gelatin water affinity Anion Coordination strength Phase Separation NTF 2 - PF 6 - (CN) 2 N - EtOSO 3 - Gelatin binds strongly to the water (CN) 2 N - EtOSO 3 - NTF 2 - PF 6 - Gelatin strips the water from IL BF 4 - Is half-way on this two cases Water affinity Coordination strength Compact rigid solids Cation Anion Il/gelatin ratio (w/w) Ion jelly State [bmim] (CN) 2 N - 1:1 Solid Transparent films. 1:3 Solid Transparent films. 6:1 Liquid gel Aliquat ® (CN) 2 N - 1:1 No Ion Jelly formation [Hmim] Cl - 1:1 Solid Transparent films. [bmim] Cl - 1:1 Solid Transparent films [omim] Cl - 1:1 Solid Transparent films. [C 10 min] Cl - 1 Solid Transparent films Aliquat ® Cl - 1 No Ion Jelly formation [bmim] PF 6 - 1 No Ion Jelly formation [bmim] BF 4 - 1 Compact rigid solids [bmim] NTF 2 - 1 No Ion Jelly formation [bmim] EtOSO 3 - 1:1 Solid Transparent films 1:3 Solid Transparent films

7. Ion Jelly Charaterizarion Differences between water gelatin and Ion Jelly Ion jelly Differential Scan Calorimetry (DSC) Water gelatin Ion jelly is stable up to 180 ºC Water removal

8. Ion Jelly Charaterizarion gelatin [bmim][N(CN) 2 ] LI/gelatina = 3) [emim][EtOSO 3 ] (LI/gelatina = 3) Water-based gelatin films exhibit three main diffracting rings at approximately 12 Ǻ, 4 Ǻ and 2.8 Ǻ High resolution ring arises from the residues periodicity of each helices turn. The rise per residue along the helical axis is 2.9 Ǻ Low resolution ring corresponds to the diameter of the super helix aggregate of the film Pronounced modifications in the conformation of the gelatin when the ionic liquid is present. X-Ray diffraction

9. Ion Jelly Charaterizarion Condutivity The conductivity of the ion jelly materials is affected by the IL used S cm -1 Decrease in conductivity on ion jelly films 25 ⁰C Several systems exhibit a very reasonable conductivity 10 -5 -10 -4 S cm -1 [Hmim][Cl] (R=1) [C 10 mim][Cl] (R=1) ; [emim][EtSO 4 ] (R=1) [bmim][Cl] (R=1) [bmim][N(CN) 2 ] (R=3) [bmim][N(CN) 2 ] (R=1)  [Him][Cl] (R=1); IL- [bmim][N(CN) 2 ] 1.1x 10 -2 [bmim][N(CN) 2 ] (R=1) 8.6x10 -5 [bmim][N(CN) 2 ] (R=3) 1.6x10 -4 IL- [bmim][Cl] 3.0x10 -2 [bmim][Cl] (R=1) 8.0x10 -4 IL- [emim][EtSO 4 ] 8.0x10 -2 [emim][EtSO 4 ] (R=1) 2,5x10 -4

10. Ion Jelly Applications Besides the ionic conductivity the material also exhibits electronic conductivity Cellulose surface [emim][EtSO 4 ] (R=1) [emim][EtSO 4 ] (R=1) + - - +

11. Ion Jelly A Applications Horseradish peroxidase as a model system Biosensor A - Free HRP; B - Immobilized HRP in Ion Jelly at liquid state; C - Immobilized HRP in Ion Jelly film after 17 days stored at 4ºC; D- Immobilized HRP in Ion Jelly film after 34 days stored at 4ºC; F- Immobilized HRP in Ion Jelly film after 40 days stored at 4ºC. Ion Jelly could be a suitable matrix for the immobilization of HRP Horseradish peroxidase immobilized in [bmim][N(CN) 2 ] (R=3) Ion Jelly 40 days 17 days 34 days Free HRP initial Gel state POSTER 91 B

12. Ion Jelly Applications 10 mV/s Immobilized protein response Electrochemical Behaviour The Ion Jelly films presented complex electrochemical behaviour Several redox processes that evolve with the continuous potential cycling A new cathodic process become visible at approximately -0.430 V vs Ag/AgCl It indicates that the direct electron transfer between the film and the cyt c was achived. Cytochrome c POSTER 89 Anaerobic conditions showed that these processes are related with the formation of hydroxide species in the interface between the film and the carbon electrode A B 15 th cycle 1 st cycle 10 mV/s 10 mV/s

13. Ion Jelly Final remarks Ion Jelly interesting concept to the develop of conducting transparent polymers Water plays an essential role of ion jelly physical-chemical properties besides ionic conductivity ion jelly also exibits electronic conductivity bioapplications could also made using this material as a conducting matrix

14. Ion Jelly REQUIMTE- FCT/UNL Prof. Joaquim S. Cabral Prof. Luis Fonseca Nuno Lourenço Cristina Cordas IBB – IST Prof. Carlos Afonso Pedro Vidinha CQFM – IST Acknowledgments Prof. Susana Barreiros Tânia Carvalho Prof. Madalena Dionísio Ana Rita Brás Prof. Maria João Romão Teresa Silva Abhik Mukhopadhyay Prof. Jorge Parola Carlos Pinheiro Thank you very much for the attention! Pedro Vidinha, Nuno Lourenço and Crístina Cordas - FCT post-doc Grants

15. Non soluble in water