Chemically Deposited Boron-Doped Diamond Screen-Printed Electrodes for the Detection of Manganese

Abstract

Manganese (Mn²⁺) is widely used in industrial applications, including steel production, battery manufacturing, and fertilizers. These activities, along with natural processes, contribute to its presence in environmental water. This study investigates the electrochemical behavior of manganese using laboratory-fabricated screen-printed carbon electrodes (SPEs) combining diamond (D), carbon black (CB), and boron-doped diamond (BDD) in eight different configurations: D + BDD, first layer (L1): CB + second layer (L2): D + BDD, CB + D + BDD, or CB pure, each of them with a chlorinated or plain pseudo-reference. The screen-printed electrodes were characterized physicochemically and electrochemically, with their electroactive areas and electron transfer resistances calculated to select the best configuration for the electroanalytical application. A voltammetric screening method for Mn²⁺ using differential pulse cathodic stripping voltammetry was developed with no preconcentration required with the SPEs L1: CB + L2: D + BDD (chlorinated) and CB + D + BDD (plain). The method exhibited broad linear ranges (1–100 and 10–100 µM) and low limits of detections (0.18 and 0.06 µM), for each SPE configuration, respectively, making it suitable for detecting Mn²⁺ in contaminated environmental water samples. The electrochemical responses showed good stability across all SPEs produced, with a relative standard deviation of less than 10% (N = 3), whether using the same or different electrodes. Interference studies with other metals confirmed the high selectivity of the proposed sensor. Additionally, Mn²⁺ was successfully detected in spiked river and lake water samples, achieving recoveries close to 100%. The analytical performance demonstrates strong potential as a simple, rapid, and selective screening method for manganese detection in environmental samples.