Electrochemical Sensing of 1-hydroxypyrene on a Colloidal Gold Modified Zeolitic Imidazolate Frameworks-67/Carbon Nanofiber Paste Electrode

Urinary 1-hydroxypyrene (1-OHP) is generally used as an exposure biomarker of polycyclic aromatic hydrocarbons (PAHs). In this work, a colloidal gold modified zeolitic imidazolate frameworks-67/carbon nanofiber paste electrode (Au@ZIF-67/CNFPE) was fabricated for the rapid and sensitive detection of 1-OHP. The morphologies of carbon nanofibers (CNF), ZIF-67, colloidal gold and colloidal gold@ZIF-67 (Au@ZIF-67) were studied by transmission electron microscopy (TEM). The electrochemical behavior of 1-OHP was investigated by square wave voltammetry (SWV). The effect factors like pH value, amount of colloidal gold, accumulation potential and accumulation time have been optimized. Under the optimal conditions, the constructed sensor responded to 1-OHP linearly in the concentration range of 0.0005–10 μM, and the detection limit was 0.1 nM. The reproducibility, stability and selectivity of this sensor were also examined. Finally, the electrode was successfully applied for the analysis of 1-OHP in human urine samples.