Recently, we reported a high-performance stretchable electrode based on networks of gold nanotubes (Au NTs) deposited on polydimethylsiloxane (PDMS) thin films. Interlacing network of Au NTs endows the sensor with desirable stability against mechanical deformation, and Au nanostructure provides excellent electrochemical performance and biocompatibility. This allowed for the first time, real-time electrochemical monitoring of mechanically sensitive cells on the sensor both in their stretching-free and stretching states as well as sensing of the inner lining of blood vessels.2 However, the sensitivity and stability of the Au NTs/PDMS electrode were not sufficient to detect very weak transient signals triggered from cells by stretching strains only. This limitation was further overcomed by implementing a percolating CNTs network onto the Au NTs backbones through transfer of a free-standing CNTs ultrathin-film onto the Au NTs/PDMS electrode. This hybrid nano-structure provides the sensor with greatly enhanced mechanical and electrochemical performances while granting very good cellular compatibility, which allowed monitoring stretch-induced transient release of vasoactive molecules by endothelial cells cultured on this sensor and submitted to stretching strains. The work represents the first step toward real-time monitoring of cell mechanotransduction by electrochemical techniques, providing a promising way toward many other direct, in real time and in situ measurements of cell mechanotransduction.
1. N. Wang, J. D. Tytell, D. E. Ingber, Nat. Rev. Mol. Cell Biol. 2009, 10, 75-82.
2. Y. L. Liu, Z. H. Jin, Y. H. Liu, X. B. Hu, Y. Qin, J. Q. Xu, C. F. Fan, W. H. Huang, Angew. Chem. Int. Edit. 2016, 55, 4537-4541.