Molecular imprinting based sensor system developed using polymeric nanoparticles for detecting 17β-estradiol in agricultural wastewater

Micro pollutants pose a significant issue in water ecosystems. Particularly high concentrations of 17β-estradiol (E2) have been identified in agricultural wastewater, which poses harmful effects on aquatic organisms and disrupts ecosystem balance. Therefore, effective determination of E2 from water sources is crucial. This study developed a biosensor capable of detecting E2 in wastewater using specific polymer nanoparticle synthesis through molecular imprinting. Est-imp-poly(multi-walled carbon nanotubes-glycidyl methacrylate [MWCNT-GMA]) polymer nanoparticles were synthesized using a surfactant-free emulsion polymerization method, and their characterization was conducted using FTIR and scanning electron microscopy (SEM) technologies. The Q_max value for Est-imp-poly(MWCNT-GMA) nanoparticles in a 1 mg/mL E2 solution was determined to be 140 ppm. Comparing adsorption capacities, the molecularly imprinted nanoparticles (MIP) showed nearly five times higher E2 adsorption compared to non-imprinted polymers (NIP). The Est-imp-poly(MWCNT-GMA)-Nafion/screen-printed electrode (SPE) system was employed for analyzing wastewater samples. The current measurements taken at various concentrations in the wastewater consistently matched the E2 concentration calibration curve. The limit of detection (LoD) and limit of quantification (LoQ) were determined to be 0.042 and 0.12 μM, respectively. The biosensor demonstrated a linear working range from 0.12 to 50 μM, with a high correlation coefficient (R² = 0.9927). These results highlight the potential of the developed biosensor for detecting E2 in real samples.