3D printed copper embedded carbon electrochemical sensors for the determination of total sugars to diagnose intestinal malabsorption

Malabsorption arises when the digestion or absorption of key nutrients, such as sugars, is impaired. While this condition can affect younger children and individuals with bowel disorders, it is particularly prevalent in the elderly. Early diagnosis of sugar malabsorption is critical for effective management; however, the widely used faecal Benedict’s reagent test frequently produces false positives and lacks sensitivity, underscoring the need for a more robust assay for total faecal sugar detection. We developed a dual-extruded (DE) 3D-printed electrode, composed of copper polylactic acid (Cu/PLA) and carbon black polylactic acid (CB/PLA) in a helix design. The DE electrode demonstrated superior stability compared to copper film-deposited CB/PLA electrodes and exhibited excellent batch-to-batch reproducibility. The DE electrode could detect both monosaccharides and disaccharides, with enhanced sensitivity toward monosaccharides. Crucially, the DE electrode identified subtle variations in total sugar levels arising from changes in concentration and composition, which Benedict’s reagent failed to detect. The DE electrode showed high selectivity for sugars over common faecal interferences and proved more effective than Benedict’s reagent in quantifying total sugars within faecal pellet samples. Notably, it detected an age-related increase in faecal sugar levels, a key diagnostic marker of malabsorption. Overall, the DE electrode represents a simple, reliable, and robust electrochemical sensor for stool analysis. By enabling sensitive and accurate measurement of total faecal sugars, it offers significant translational potential as a diagnostic screening tool for malabsorption, advancing clinical practice.