Non-Enzymatic Voltammetric Sensor for Histamine Determination in Saliva for Point-of-Care Diagnostics

The evaluation of histamine levels in saliva can be used as one of the diagnostic criteria for detecting many diseases. Therefore, a sensitive, simple, and low-cost method for determining histamine concentrations is needed for point-of-care diagnostics. In this work, the use of a glassy carbon disk electrode, bulk graphite composite electrode, and graphite screen-printed electrode modified with CuO nanoparticles and CuSO4 for histamine quantification by cyclic voltammetry was studied. The best results were obtained using the screen-printed sensor with the working electrode modified by a CuSO4 aqueous solution and covered with a Nafion-like polymer film. The developed sensor showed a 5 × 10–9 M detection limit with a broad linear range from 5 × 10–9 to 1 × 10–6 M of histamine in a phosphate buffer solution, providing sufficient reliability for saliva analysis after simple sample preparation. The analysis of real saliva samples revealed no significant interfering matrix effect. The total analysis time, including sample preparation, did not exceed 15 minutes.