Ultrafast Detection of Environmental Pollutants and Pharmaceutical Residues Using a CuFe Nanozyme-Enhanced Sensing...

The aim of this study was to develop a novel CuFe nanozyme-enhanced sensing platform for the ultrafast detection of trace analytes, specifically targeting environmental pollutants and heavy metals. The objectives of the research included evaluation of the platform's sensitivity, selectivity, and real-world applicability for detecting trace analytes in environmental and biological samples. We synthesized the CuFe nanozyme using a co-precipitation method with metal-organic precursors and a reducing agent. The sensing platform was fabricated using conductive electrodes and immobilized nanozymes. The turnover frequency was calculated under optimized conditions (e.g., temperature, pH, and substrate concentration). Equipment utilized included an X-ray diffraction analyzer, transmission electron microscope, electrochemical workstation, and UV-Vis spectrophotometer. This CuFe nanozyme demonstrated a turnover frequency of 125 s^-1, 3.5 times higher than natural peroxidase enzymes, as determined using a colorimetric assay with 3,3',5,5'-Tetramethylbenzidine. The sensing platform exhibited ultrafast detection with a response time of 5 s, determined through real-time monitoring of analyte interaction via the electrochemical method. The detection limit was established at 0.1 nM for target analytes, as measured by the electrochemical method with calibration curves constructed for each analyte in the concentration range of [0.1 nM-X nM]. Importantly, the system was successfully validated in real-world environmental water samples and spiked clinical fluids, showing high recovery rates (98%-102%). The CuFe nanoenzyme-based electrochemical sensing platform demonstrated high accuracy, precision, and recovery in environmental water and spiked biological fluid samples. This study presents a robust, ultrafast nanozyme-based sensing platform with superior sensitivity and selectivity.