Non-enzymatic glucose sensing Au-Ti platform covered with photopolymerized poly(zwitterionic) coating with enhanced selectivity and durability in human serum

Non-enzymatic electrochemical glucose sensors have numerous potential advantages over traditional enzymatic ones. Among them, one can distinguish cheaper and easier fabrication route, as well as higher resistance towards pH and temperature changes. However, there are certain drawbacks of non-using enzymes, i.e. low selectivity towards glucose and threat of interference with other electroactive compounds such as ascorbic acid (AA), acetaminophen (AAp), acetylsalicylic acid (AsA), urea and aminoacids [1]. Therefore, there is a strong requirement for strategies enhancing the selectivity by eliminating interference and prolonging the sensing capability in human physiological fluids.

In here, we present glucose sensitive Au-Ti electrodes obtained via anodization of Ti foil and their subsequent chemical etching [2]. Later on, thin gold film is sputtered and further dewetted, so that gold nanoparticles are created and embedded in the titanium template. As a coating for studied electrode we propose photopolymerized sulfobetaine methacrylate crosslinked with ethylene glycol dimethacrylate (p(SBMA:EGDMA)). Polymeric zwitterions are a promising solution due to their superhydrophilicity and high resistivity to biofouling in media containing various biomoleclues and cells [3]. According to our results, pSBMA:EGDMA coating provides significant interference reduction from AA, aminoacids, AsA and urea. Moreover electrochemical activity is preserved in diluted human serum indicating possible application of fabricated material in glucose monitoring in real samples.

References:

[1] Hwang, D. W., Lee, S., Seo, M., & Chung, T. D. (2018). Recent advances in electrochemical non-enzymatic glucose sensors–a review. Analytica Chimica Acta, 1033, 1-34.

[2] Olejnik, A., Siuzdak, K., Karczewski, J., & Grochowska, K. (2020). A Flexible Nafion Coated Enzyme‐free Glucose Sensor Based on Au‐dimpled Ti Structures. Electroanalysis, 32(2), 323-332.

[3] Venault, A., & Chang, Y. (2018). Designs of zwitterionic interfaces and membranes. Langmuir, 35(5), 1714-1726.

.Acknowledgements

This work has been financed by National Center for Research and Development under the LIDER program (LIDER/2/0003/L-8/16/NCBR/2017)