Cancer cell culture medium identification by tailoring super hydrophobic properties of organic electrochemical biosensor

Organic electrochemical transistors devices, based on the conductive polymer PEDOT:PSS, have been demonstrated in chemical and biological sensing: while accurate in determining the size of individual ions in solution 1-2, similar devices present sensing limits if challenged with complex mixtures, due to the lack of spatial resolution. Here, we modified a conductive PEDOT:PSS polymer to include extra non-continuous scales in the device. Super-hydrophobic SU8 pillars, positioned on the substrate to form a non-periodic square lattice, allows a pattering of the polymer surface, in which the distance between the pillars smoothly transitions from the center to the periphery of the pattern. The pillars incorporate a finite number of micro-electrodes in a line that represent the active or sensitive part of the device. Conductive PEDOT:PSS is used to cover the device and a fluorocarbon polymer assures the hydrophobicity of the device. The liquid solution on a similar device would maintain a spherical shape as suspended in air. Marangoni convective flows develop within the volume of a drop of solution, due to its spherical curvature. The competition between convection and diffusion will cause a spatial separation of biological species that would depend on the size and charge of the species in a solution. Time and space resolved measurement of the solution have been realized. The described device may operate the identification and separation of different species mingled up in a solution with high sensitivity, selectivity and reliability. Then we operate the analysis of the culture medium collected during the exponential phase growth of circulating cell isolated form peripheral blood of health, sub-clinical and colon cancer patients. The culture mediums were conditioned during a short-time cultivation of fourteen days performed as previously described (3). The unsupervised classification of the described datasets into defined groups with a small error suggests that the method may be used for the evaluation of the health status without affecting the performance status of the patient, which may both have major benefits for the national health care. References [Ref1] R. M. Owens, G.G. Malliaras, MRS Bulletin 35, (2010) 449-456 [Ref2] N. Coppedè, M. Villani, F. Gentile, Scientific Reports 4, (2014) 1-7 [Ref3] N. Malara, M.L. Givigliano F. et al J Biol Regul Homeost Agents. 4, (2014) 717-31. Nicola Coppedè