Copper film electrode for sensitive detection of nitrophenols

•Copper film electrode (CuFE) as a mercury-free sensor for the detection of nitrophenols.•Simple in situ preparation protocol during cathodic voltammetric scan.•Electrode surface activation, copper film deposition, and measurement in a single step.•CuFE enables detection in the low μg L−1 range along with excellent repeatability.•CuFE allows sensitive detection of other nitroaromatic compounds. In this study, we present a copper film electrode (CuFE) for sensitive voltammetric detection of nitrophenols. The detection scheme comprised an electrochemical oxidative activation of a glassy carbon supporting electrode, an in situ formation of CuFE, and a measurement step. All three steps were performed simultaneously in a single cathodic voltammetric scan. Several critical parameters influencing the operation of CuFE were examined and optimized, such as the concentration of copper ions, pH, potential scan, activation time, etc. The CuFE showed excellent electroanalytical performance for the detection of selected mono-, di-, and trinitrophenols with good sensitivity in the low μg L−1 concentration range and favorable repeatability. The practical applicability of this sensor was successfully demonstrated by measuring 2,4-dinitrophenol, as a test analyte, in a real seawater sample.