Impact of Polymer Microstructure and Free Volume on Electrochemical Biosensor Functionality

Taras Kavetskyy

Abstract

This review presents a comprehensive and quantitatively oriented analysis of the role of polymer microstructure and free volume in governing the performance of electrochemical biosensors. Particular emphasis is placed on the application of positron annihilation spectroscopy (PAS) as a uniquely sensitive technique for probing sub-nanometer free-volume characteristics and establishing direct structure–function relationships. By integrating results from organic-inorganic hybrid ureasil-based and photocross-linked polymers, a consistent correlation is demonstrated between free-volume parameters (size, distribution, and thermal expansion) and key biosensor characteristics, including sensitivity, mass transport efficiency, and enzyme activity. It is shown that variations in free-volume cavity size and connectivity systematically control analyte diffusion, enzyme accessibility, and reaction kinetics within polymer matrices. Furthermore, the combined influence of network topology (crosslinking density, phase separation) and chemical functionality (polymer composition, photoinitiator effects) on free-volume evolution during polymerization and aging is elucidated. In-situ PAS studies of photopolymerization reveal that kinetic pathways directly determine the final microstructure and, consequently, the functional performance of biosensing platforms. Based on these insights, a generalized framework is proposed in which free volume acts as a key design parameter linking nanoscale polymer structure to macroscopic electrochemical response. This approach provides a rational basis for engineering polymer matrices for biosensors with optimized sensitivity, selectivity, and operational stability, offering new directions for the development of next-generation biosensors.

References

1.
Jean, Y.C. Positron annihilation spectroscopy for chemical analysis: A novel probe for microstructural analysis of polymers. Microchem. J. 1990, 42, 72–102. https://doi.org/10.1016/0026-265X(90)90027-3.
2.
Kavetskyy, T.; Boev, V.; Ilcheva, V.; et al. Structural and free volume characterization of sol-gel organic-inorganic hybrids, obtained by co-condensation of two ureasilicate stoichiometric precursors. J. Appl. Polym. Sci. 2021, 138, e50615. https://doi.org/10.1002/app.50615.
3.
Dahmouche, K.; Santilli, C.V.; Pulcinelli, S.H.; et al. Small-angle X-ray scattering study of sol-gel-derived siloxane-PEG and siloxane-PPG hybrid materials. J. Phys. Chem. B 1999, 103, 4937–4942. https://doi.org/10.1021/jp984605h.
4.
Chen, H.M.; Jean, Y.C.; Lee, L.J.; et al. Positron annihilation study in inorganic-polymer nano-composites. Phys. Stat. Sol. C 2009, 6, 2397–2400. https://doi.org/10.1002/pssc.200982136.
5.
Kavetskyy, T.S.; Smutok, O.; Gonchar, M.; et al. Ureasil-based polymer matrices as sensitive layers for the construction of amperometric biosensors. In Advanced Nanotechnologies for Detection and Defence against CBRN Agents; Petkov, P., Tsiulyanu, D., Popov, C., et al., Eds.; NATO Science for Peace and Security Series B: Physics and Biophysics; Springer: Dordrecht, The Netherlands, 2018; pp. 309–316. https://doi.org/10.1007/978-94-024-1298-7_30.
6.
Kavetskyy, T.; Smutok, O.; Demkiv, O.; et al. Dependence of operational parameters of laccase-based biosensors on structure of photocross-linked polymers as holding matrixes. Eur. Polym. J. 2019, 115, 391–398. https://doi.org/10.1016/j.eurpolymj.2019.03.056.
7.
Goździuk, M.; Kavetskyy, T.; Massana Roquero, D.; et al. UV-cured green polymers for biosensorics: Correlation of operational parameters of highly sensitive biosensors with nano-volumes and adsorption properties. Materials 2022, 15, 6607. https://doi.org/10.3390/ma15196607.
8.
Královič, D.P.; Cifraničová, K.; Švajdlenková, H.; et al. Effect of aromatic rings in AESO-VDM biopolymers on the local free volume and diffusion properties of polymer matrix. J. Polym. Environ. 2024, 32, 2336–2349. https://doi.org/10.1007/s10924-023-03097-1.
9.
Kavetskyy, T.; Zubrytska, O.; Stievenard, M.; et al. Complex network methods, PALS, ATR-FTIR and EPR study of photopolymerization. In Nanotechnological Advances in Environmental, Cyber and CBRN Security; Petkov, P., Achour, M.E., Popov, C., Eds.; NATO Science for Peace and Security Series B: Physics and Biophysics; Springer: Dordrecht, The Netherlands, 2025; pp. 265–284. https://doi.org/10.1007/978-94-024-2316-7_19.
10.
Kavetskyy, T.S.; Zubrytska, O.V.; Matskiv, O.I.; et al. Photopolymerization and photodegradation of polymers after long-term UV light exposure. Phys. Chem. Solid State 2025, 26, 718–732. https://doi.org/10.15330/pcss.26.4.718-732.
11.
Shim, H.-E.; Lee, B.-M.; Lim, D.-H.; et al. A comparative study of gamma-ray irradiation-induced oxidation: Polyethylene, poly (vinylidene fluoride), and polytetrafluoroethylene. Polymers 2022, 14, 4570. https://doi.org/10.3390/polym14214570.
12.
Liu, S.; Li, Q.; Wang, J.; et al. Study on the post-irradiation oxidation of polyethylenes using EPR and FTIR technique. Polym. Degrad. Stab. 2022, 196, 109846. https://doi.org/10.1016/j.polymdegradstab.2022.109846.
13.
Kavetskyy, T.; Kukhazh, Y.; Hoivanovych, N.; et al. On the correlation of network properties of polymer matrixes with parameters of electrochemical biosensors. Acta Carpathica 2024, 1, 105–116. https://doi.org/10.32782/2450-8640.2024.1.11.
14.
Kavetskyy, T.; Smutok, O.; Demkiv, O.; et al. Microporous carbon fibers as electroconductive immobilization matrixes: Effect of their structure on operational parameters of laccase-based amperometric biosensor. Mater. Sci. Eng. C 2020, 109, 110570. https://doi.org/10.1016/j.msec.2019.110570.
15.
Kavetskyy, T.; Smutok, O.; Goździuk-Gontarz, M.; et al. Impact of chemical composition of soybean oil and vanillin-based photocross-linked polymers on parameters of electrochemical biosensors. Microchem. J. 2024, 201, 110618. https://doi.org/10.1016/j.microc.2024.110618.
16.
Kavetskyy, T.; Kukhazh, Y.; Demkiv, O.; et al. Organic-inorganic ureasil-based composites with sulfur for biosensors. In Nanotechnological Advances in Environmental, Cyber and CBRN Security; Petkov, P., Achour, M.E., Popov, C., Eds.; NATO Science for Peace and Security Series B: Physics and Biophysics; Springer: Dordrecht, The Netherlands, 2025; pp. 513–519. https://doi.org/10.1007/978-94-024-2316-7_39.
17.
Smutok, O.; Kavetskyy, T.; Prokopiv, T.; et al. New micro/nanocomposite with peroxidase-like activity in construction of oxidases-based amperometric biosensors for ethanol and glucose analysis. Anal. Chim. Acta 2021, 1143, 201–209. https://doi.org/10.1016/j.aca.2020.11.052.
18.
Brunauer, S.; Emmett, P.; Teller, E. Adsorption of gases in multimolecular layer. J. Am. Chem. Soc. 1938, 60, 309–319. https://pubs.acs.org/doi/10.1021/ja01269a023.
19.
Kavetskyy, T.; Tuzhykov, A.; Fink, D.; et al. Positron annihilation and AI-technology for creation of novel biosensors. J. Phys. Conf. Ser. 2025, 3149, 012028. https://doi.org/10.1088/1742-6596/3149/1/012028.

Scilight Press

Author Information

Abstract

Keywords

References

About Scilight

Journals

Publishing Policies

Contact Us