Lignin-Integrated Conductive Polymers for Advanced Applications
The rapid expansion of digital health technologies, wearable electronics, and point-of-care diagnostics is driving demand for next-generation biosensors that are not only high-performing but also sustainable and biocompatible. At the heart of many modern biosensors are organic mixed ionic–electronic conductors (OMIECs), which are capable of transporting both ions and electrons. These materials are critical for establishing effective signal transduction between biological systems and electronic devices, enabling real-time detection of physiological and environmental analytes.
OMIECs based on synthetic conjugated polymers — such as polypyrrole (PPy), polythiophene (PT), and their derivatives — have shown strong promise in biosensing due to their tunable conductivity, softness, and compatibility with aqueous media. However, these materials are typically derived from fossil-based feedstocks, exhibit limited biodegradability, and often require environmentally intensive synthesis routes. To meet growing global expectations around circularity, sustainability, and green chemistry, there is an urgent need to develop OMIECs using renewable and eco-friendly building blocks.
Lignin, an abundant, renewable, and underutilized biopolymer offers a compelling opportunity in this context. As the second most abundant polymer on Earth, lignin features a rich aromatic structure with a variety of reactive functional groups that make it suitable for chemical tailoring and hybridization. Despite its potential, lignin has historically been overlooked in high-value applications such as bioelectronics due to its structural complexity and heterogeneity. However, recent advances in lignin extraction, fractionation, and surface modification have significantly improved its processability and performance in nanocomposites.
This project proposes the development of lignin–conductive polymer bio-nanocomposites as sustainable OMIECs tailored for biosensor applications. These hybrids aim to combine the electrical performance of conjugated polymers with the renewable, biodegradable, and mechanically robust nature of lignin. By leveraging the synergy between these two components, the resulting materials are expected to exhibit improved ionic–electronic transport, mechanical flexibility, and environmental compatibility.
The proposed research includes:
1. Chemical functionalization of lignin to improve solubility, charge transport, and compatibility with conjugated polymers (e.g., sulfonation or oxidative modification).
2. In situ polymerization or grafting of PPy or PT and homemade conductive polymers onto lignin nanoparticles, fibers, or films to create structured OMIECs with controlled morphology and electroactivity.
3. Comprehensive characterization of the physical, electrochemical, and morphological properties of the composites using techniques such as impedance spectroscopy, cyclic voltammetry, SEM, and AFM.
4. Integration into biosensor platforms, particularly for electrochemical detection of biomarkers (e.g., glucose, lactate, heavy metals), where ionic–electronic coupling is essential for sensitivity and stability.
These bio-derived OMIECs are expected to deliver high conductivity, low interfacial impedance, and excellent biocompatibility—key features for wearable and implantable sensors. Furthermore, the use of lignin enables greener synthesis and end-of-life degradation options, aligning with life cycle thinking and circular material principles.
By advancing lignin–based OMIECs, this research supports the development of scalable, cost-effective, and environmentally responsible biosensor technologies. The approach bridges sustainable chemistry and functional materials science, contributing to both fundamental knowledge and practical innovation in bioelectronics and diagnostics.
Yevgen Karpichev (ORCID ID: 0000-0003-2322-6750) is a Senior Researcher at the Tallinn University of Technology (TalTech), Estonia. The Karpichev's group research is focused on green and sustainable methods of organic chemistry applied to biomass valorisation, medicinal chemistry, and designing functional materilas. Yevgen obtained his PhD in 2002 (Ukraine) and was a Visiting Researcher at the University of California, Santa Barbara with Prof. C.A. Bunton, to develop organized molecular systems for special applications. Yevgen completed a postdoctoral fellowship at Dalhousie University (Canada) by Atlantic Innovation Fund and Newpark Canada Inc. on oilfield remediation. He continued as a CNRS Researcher at European Institute of Chemistry and Biology (Bordeaux, France) and at the Laboratory of IMRCP (Toulouse, France). Dr. Karpichev served as a Visiting Professor at Paul Sabatier University (Toulouse, France) in 2009, University of Hradec Králové (Czech Republic) in 2014, and the Pontifical Catholic University of Rio de Janeiro (Brazil) in 2023. In 2015 - 2019, he was a Senior Research Scientist of the ERA Chair of Green Chemistry at TalTech. In 2019, he established his own Sustainable Chemistry and Engineering research group. He supervised or is being a (co)supervisor of 8 PhD students and 10 international MSc students.
Current research focus: Sustainable chemistry; Chemical valorisation of lignin; Functional materials
Number of Publications: 64
Key Funding:
TEM-TA49, Chemical and biological valorization technologies for woody biomass and secondary lignocellulose sources (Estonian Research Council, 2024-2028);
VEU23002, Surveillance and Reconnaissance Techniques for Chemical and Biological Threats (European Defence Fund, 2022−2025);
TK228U1, Centre of Excellence in Circular Economy for Strategic Mineral and Carbon Resources (Estonian Research Council, 2024-2028);
Jean-Manuel Raimundo (ORCID ID: 0000-0003-4090-0479) is Full Professor at the Centre Interdisciplinaire de Nanoscience de Marseille (CINaM – UMR 7325, CNRS/Aix-Marseille University) since 2015, where he leads a multidisciplinary research group working at the interface of supramolecular and organic chemistry, electrochemistry, surface functionalization, and physical chemistry. His research focuses on the design of functional materials for optoelectronics, (bio)sensing, bioelectronics, nanomedicine, and drug delivery. He holds a B.Sc. in biochemistry from the University of Rennes and a Ph.D. in organic chemistry from the University of Angers under the supervision of Dr. J. Roncali, followed by postdoctoral training at ETH Zurich with Prof. F. Diederich. He held academic appointments at the University of Angers and Université de Nice, including a collaboration with TotalFina Elf, before joining Aix-Marseille University in 2008 and becoming Associate Professor in 2011. Author of over 90 peer-reviewed publications (h-index ~29), Prof. Raimundo has made significant contributions in the areas of push-pull chromophores, conjugated polymers, organic field-effect transistors, and their biomedical applications. He supervises Ph.D. and postdoctoral researchers and is an active contributor to international scientific conferences. In 2024, he co-founded Silon Therapeutics, a start-up focused on translating nanoscience innovations into therapeutic solutions.
Qualifications:
The candidate should hold a master’s degree (or equivalent) in chemistry, materials science, or a related field. A strong foundation in organic synthetic chemistry, polymer science, or electrochemistry is essential. Prior experience with biopolymers (e.g., lignin), conjugated polymers, or biosensor development is highly desirable. Relevant coursework or research in functional materials will be considered an asset.
Requirements:
The candidate must demonstrate hands-on skills in chemical synthesis and materials characterization (e.g., spectroscopy, microscopy, electrochemical analysis). Strong analytical thinking, teamwork, and communication skills (written and oral) in English are required. Motivation to work in an interdisciplinary, innovation-driven research environment is essential.