Silicone glue-based graphite ink incorporated on paper platform as an affordable approach to construct stable electrochemical sensors.

This study describes the development of electrochemical paper-based analytical devices (ePADs) using carbon-based paste combining silicone glue and graphite powder. The ePADs were manufactured using the screen-printing technique, which consisted of depositing the conductive ink on a screencast on the paper surface. In addition, an alternative electrical connector was designed and 3D-printed to make the detection method cheaper, portable and reproducible. The morphological, structural, and electrochemical properties of the conductive material developed were investigated through scanning electron microscopy (SEM), Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements. The ePADs combined with the alternative connector revealed high repeatability, reproducibility, and stable responses considering a well-known redox probe ([Fe(CN) 6 ]4-/3-). In addition, the proposed ePAD provided a linear response for standard solutions of ascorbic acid (AA) in the concentration range between 0.1 and 2.0 mmol L−1. The achieved limit of detection was 4.0 μmol L−1. As proof of applicability, the ePADs were evaluated for AA analysis in synthetic biofluids (blood plasma and urine), vitamin C tablets, and food (gelatine and orange juice) samples. The analytical parameters of the proposed device were compared with other reports in the literature and exhibited similar or even superior performance, highlighting its feasibility for sensing applications. [Display omitted] • A carbon-based ink prepared by mixing graphite powder and silicone glue was used to develop screen-printed electrodes on paper. • An inexpensive 3D printed holder ensured simple assembling and suitable reproducibility. • Paper-based sensors revealed great stability and analytical performance. • Ascorbic acid was successfully determined in different samples. [ABSTRACT FROM AUTHOR]