Flexible biodegradable electrochemical sensor of PBAT and CNDs composite for the detection of emerging pollutants

Herein we proposed the fabrication and optimization of a flexible electrochemical sensor composed of polymer poly(butylene adipate-co-terephthalate) (PBAT) and Carbon Nitrite Dots (CNDs). The materials stand out for being low-cost, flexible, biodegradable, and easily discarded after use. Characterization was performed by Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), contact angle, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). The sensor was used to simultaneously detect emerging pollutants such as cadmium and copper by Square Wave Anodic Stripping Voltammetry (SWV) technique. As result, a linear behavior in the concentration range of 0.1 to 1.0 mM for cadmium and copper showed excellent electrochemical activity with sensitivity of (3.79 ± 0.21) × 10−5 (mA cm−2) (M)−1 for cadmium and (2.06 ± 0.14) × 10−5 (mA cm−2) (M)−1 for copper. The LD and LQ values obtained for cadmium were 2.75 × 10−6 M and 9.16 × 10−6 M, and for copper were 7.09 × 10−6 M and 2.36 × 10−5 M, respectively. Therefore, the sensors obtained in this work have the advantage of simultaneously detecting emerging pollutants such as cadmium and copper, including real tap water samples.