Development of a skin-like sensor for monitoring an inflammatory biomarker for wound care application

• Autor(a) principal: Lourenço, Carolina Neves
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/156040
• topic: biosensor; molecularly-imprinted polymer; flexible substrate; gold-based electrodes; electrochemical; interleukin; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

Globally, wound management poses a massive challenge with a great impact on social-economic and healthcare systems. In a post-Covid era, at-home diagnostic and monitoring devices gained a crucial role in our lives, boosting the development of novel skin patch sensors targeted for health monitoring. In this context, one of the most important requirements concerns the creation of flexible and conformable conductive platforms that can be employed as skin-like sensors. Thus, the main goal of this dissertation consists in the development of a flexible electrochemical biosensing device for the detection of an inflammation biomarker, interleukin-6 (IL-6). The 3-electrode gold pattern was standardized by e-beam evaporation on a 6 μm polyimide membrane, a transparent and biocompatible polymeric material. Subsequently, protein-printed sensors were electrochemically fabricated on the gold-modified electrodes for IL-6 detection. This biorecognition is accomplished with molecularly-imprinted polymers (MIPs) that were synthesized on the electrode surface by electropolymerization of a mixture of two monomers, pyrrole and carboxylated pyrrole. Along this process, several electropolymerization parameters were optimized like the potential range and number of cycles, as well as the pH conditions of the medium and the removal of the imprinted protein, to create the cavities responsible for the rebinding event. Electrochemical sensing features were then investigated to demonstrate the imprinting effect and the optimized biosensor exhibited a linear electrochemical response in the 0.5 ng/mL to 500 ng/mL concentration range. Moreover, chemical, and morphological characterizations, such as XPS, SEM and FTIR confirmed the surface modifications on the gold surface. The final biosensing device demonstrated great potential in terms of sensitivity, stability, and reproducibility, making it a simpler and more cost-effective portable solution for the remote monitoring of chronic wounds. Finally, the incorporation of the sensing component directly on biocompatible flexible polymers enables new monitoring and treatment tools that can be more accurate, less invasive, and more comfortable for the patient.