A novel disposable self-adhesive inked paper device for electrochemical sensing of dopamine and serotonin neurotransmitters and biosensing of glucose.

In this work, we detail the progress of a novel electrochemical disposable device, which has a relatively low cost and easy production, with a novel conductive ink, that consists of graphite and automotive varnish mixture, deposited over a self-adhesive paper, granting an easy production with relatively low cost. The electrode surface was characterized by scanning electron microscopy, X-ray powder diffraction and Fourier transforms infrared and Raman, cyclic voltammetry and electrochemical impedance spectroscopies. In addition, the proposed electrode was applied for individual electrochemical determination of dopamine and serotonin. The device achieved a linear response between 30 and 800 μmol L-1 and a limit of detection (LOD) of 0.13 μmol L-1, by square wave voltammetry for dopamine and a linear range from 6.0 to 100 μmol L-1, with a LOD of 0.39 μmol L-1, by differential pulse voltammetry for serotonin. Later, the working electrode was modified with glucose oxidase and dihexadecyl phosphate film in order to obtain a biosensor. At this stage, CV was applied to detect glucose in the range of 1.0-10 μmol L-1 and LOD of 0.21 μmol L-1. By three different techniques and analytes, the sensoring and biosensoring processes presented high reproducibility. The proposed adhesive electrode is easy to prepare, disposable, within non-restrictive nature, which allows an approach of a new device for electrochemical sensing and biosensing.