A Highly Sensitive Electrochemical Sensor for Cd²⁺ Detection Based on Prussian Blue-PEDOT-Loaded Laser-Scribed Graphene-Modified Glassy Carbon Electrode

Abstract

Heavy metal ion pollution has had a serious influence on human health and the environment. Therefore, the monitoring of heavy metal ions is of great practical significance. In this work, we describe the development of an electrochemical sensor to detect cadmium (Cd2+) using a Prussian blue (PB), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT)-loaded laser-scribed graphene (LSG) nanocomposite-modified glassy carbon electrode (GCE). In this nanocomposite material, we successfully brought together the advantages of an extraordinarily large surface area. The accumulation of PB nanoparticles results in an efficient electrochemical sensor with high sensitivity and selectivity and fast detection ability, developed for the trace-level detection of Cd2+. Electrochemical features were explored via cyclic voltammetry (CV), whereas the stripping voltammetry behavior of modified electrodes was analyzed by utilizing differential pulse voltammetry. Compared with bare GCE, the LSG/PB-PEDOT/GCE modified electrode greatly increased the anodic stripping peak currents of Cd2+. Under the optimized conditions, the direct and facile detection of Cd2+ was achieved with a wide linear range (1 nM–10 µM) and a low LOD (0.85 nM).

Keywords

• Prussian blue
• heavy metal ion
• cadmium electrochemical sensor
• laser-scribed graphene
• glassy carbon electrode