Water-Based Conductive Ink for the Production of Carbon Black Screen-Printed Electrodes and the Detection of Tryptophan
Jéssica Rocha Camargo, Robert D. Crapnell, Elena Bernalte, Bruno C. Janegitz, Craig E. Banks
Abstract
High Resolution Image Download MS PowerPoint Slide The development of versatile, cost-effective, and reproducible electrochemical sensors has gained importance due to their adaptability to specific applications through variations in composition and design. Water-based conductive inks have emerged as environmentally friendly alternatives to meet sustainability requirements and eliminate hazardous solvents. In this study, a screen-printed electrode (SPE) sensor utilizing a water-based conductive ink composed of Carbon Black Super P (CBSP), poly(vinylpyrrolidone) (PVP) and chitosan is presented. The ink formulation was optimized for a 5% CBSP composition, resulting in a homogeneous surface and superior reproducibility with a relative standard deviation of 7.99% ( n = 5). The optimized sensor exhibited quasi-reversible behavior in cyclic voltammetry and an electroactive area 198.57% larger than its geometric area. The analytical performance for tryptophan detection showed a linear range from 0.5 to 300 μmol L –1 ( R 2 = 0.9946), a limit of detection of 0.018 μmol L –1, and interference rates below 10% for common compounds. The recovery rates for pharmaceutical and beverage samples ranged from 86.2% to 114%. The sustainable design, excellent sensitivity, and cost-effective manufacturing make this SPE sensor a robust tool for point-of-use tryptophan quantification.