Au/Vulcan@chitosan nanocomposite as a simple and cost˗effective sensing interface for the voltammetric detection of 17β˗estradiol

Emerging micropollutants, particularly endocrine disruptors like 17β˗estradiol (E2), pose significant environmental and health risks due to their toxicity and bioaccumulation. This work presents the development of a novel, cost˗effective electrochemical carbon sensor, screen˗printed on a commercial PVC substrate, for the sensitive and selective detection of E2. The sensor’s working electrode was modified through a layer˗by˗layer deposition of Vulcan XC72R carbon (2.5 mg mL˗1) dispersed in chitosan (0.5% w/v), followed by chronoamperometric electrodeposition of metallic Au. Electrochemical characterization, performed via cyclic voltammetry (CV), confirmed significant enhancement in the electrode’s response after modification. Optimal E2 detection was achieved at pH 3.5 using Differential Pulse Voltammetry (DPV) in 0.1 mol L⁻1 PBS. The sensor demonstrated a wide linear dynamic range from 0.10 to 45.00 µmol L⁻1, with a high R² of 0.992 and a low limit of detection (LOD) of 0.025 µmol L⁻1. Recovery studies in diverse matrices—including river water, blood serum, and synthetic urine—yielded high recoveries between 98.7% and 111.4%, indicating excellent accuracy. Furthermore, interference tests confirmed the sensor’s high selectivity against common co˗existing substances. This Au/Vulcan@chitosan˗modified electrochemical device offers a cost-effective, disposable, and easily deployable alternative for robust and accurate 17β˗estradiol quantification in various environmental and biological samples.