Creative 3D-printed electrochemical sensors for the detection of biomolecules within the bowel

Abstract

Age-related bowel dysfunction is associated with digestive issues arising from reduced nutrient absorption and altered gut motility. These age-dependent changes can significantly diminish quality of life and often contribute to social isolation. Because nutrient absorption and gut motility are regulated by key biomolecules, there is increasing interest in how these molecules change with age and whether they can function as potential diagnostic biomarkers. Electrochemical sensors have shown strong potential for measuring biomolecules within the bowel. However, current manufacturing approaches are time-consuming, and conventional electrodes are often fragile, limiting their routine use. In addition, most electrodes rely on restricted and repetitive geometries, which constrain opportunities to enhance performance.
To overcome these limitations, Fused Filament Fabrication (FFF) 3D printing has emerged as a promising method for producing electrochemical sensors in a simple, reproducible, and cost-effective manner. Despite these advantages, 3D-printedelectrodes typically exhibit reduced conductivity, which lowers sensitivity and hinders their effectiveness for biological detection. Therefore, this thesis aims to investigate how creatively engineered electrode surface geometries can enhance the electrochemical performance of 3D-printed electrodes. It also explores their potential for measuring age-related changes in biomolecules associated with bowel function.
Paper, one examined how electrode surface geometry influences electrochemical performance. Straight-edged patterns produced a stronger electrochemical response than standard flat electrodes. Paper two showcased that patterning the electrode can vary the deposition of gold nanoparticles, in which the knurl pattern had the highest current response. Using this electrode, an age-related decrease in nitrite was observed in faecal pellets. Paper three investigated dual-extruded carbon–copper electrodes for detecting sugars in faecal pellets as a marker of malabsorption. These sensors demonstrated an age-related increase in sugars, which was not detected by the Benedict’s reagent. Finally, paper four developed a 3D-printed knurl patterned electrochemical immunosensor for the detection of Neurokinin A. The immunosensor detected age-related differences in NKA release and content from colonic tissue.
In conclusion, this work demonstrates that creatively engineered surface patterning on 3D-printed electrodes can enhance electrochemical performance. The sensors developed throughout this research could detect key biomolecules within the bowel and revealing how their levels change with age. These biomolecular signatures show strong potential as early predictive markers of age-related bowel dysfunction, highlighting the value of 3D-printed electrochemical platforms for future diagnostic development.

Date of Award	May 2026
Original language	English
Awarding Institution	University of Brighton
Supervisor	Bhavik Patel (Supervisor) & Mark Yeoman (Supervisor)