Development of 3D sensors for neurotransmitters determination: a comparative study of conductive filaments

• Grant number: 25/22840-8
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: January 05, 2026
• End date: February 24, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Bruno Campos Janegitz
• Grantee: Sidnei de Barros Gomes Junior
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

This project aims to develop 3D-printed electrochemical sensors for the determination of neurotransmitters, specifically dopamine and epinephrine, using different conductive filaments produced from polymer-carbon black (CB) composites. The work will be carried out during a short-term research internship at the Laboratory of Sensors, Nanomedicine, and Nanostructured Materials, under the supervision of Prof. Dr. Bruno Campos Janegitz (UFSCar), in collaboration with the research group of Prof. Dr. Rafael de Queiroz Ferreira (UFES), strengthening the partnership between the two institutions.Conductive filaments are the core materials for 3D-printed electrochemical sensors, allowing precise control over geometry, reproducibility, and analytical performance. In this study, filaments composed of polylactic acid (PLA), polypropylene (PP), and PLA/PP blends will be prepared, each containing 25% CB (VULCAN® XC72) as the conductive phase and babassu oil as a plasticizer. The selected polymers offer complementary advantages: PLA provides easy printability and biodegradability, while PP exhibits superior chemical and thermal resistance. The hybrid PLA/PP/CB composition is expected to combine the favorable properties of both polymers, representing an innovative route for producing filaments with enhanced mechanical and electrical performance.The resulting filaments will be processed by fused deposition modeling (FDM) to fabricate 3D-printed electrodes. These sensors will be characterized morphologically (scanning electron microscopy - SEM), structurally (X-ray diffraction - XRD, and Fourier-transform infrared spectroscopy - FTIR), and electrochemically (cyclic voltammetry and electrochemical impedance spectroscopy). Their analytical performance will be evaluated and compared for the detection of dopamine and epinephrine-biomolecules of significant biomedical relevance related to neurological and cardiovascular disorders.Beyond the scientific scope, the project also has an important training dimension. The internship will provide hands-on experience in conductive filament manufacturing and extrusion, integrating expertise in polymeric materials, 3D printing, and electroanalytical methods applied to biosensing. The expected outcomes will contribute to advancing sustainable, low-cost conductive materials for sensor fabrication, with potential applications in clinical and environmental monitoring.This project will reinforce the collaboration between UFES and UFSCar research groups, fostering the training of qualified human resources and promoting knowledge exchange. It aligns with the objectives of the Aristides Pacheco Leão Program for the Stimulation of Scientific Vocations (FAPESP) by combining academic formation, technological innovation, and practical application in an interdisciplinary context.