This study presents a sustainable approach for transforming food waste into functional electrochemical materials by utilizing copper-enriched cabbage leaves as a precursor for carbon-based sensors. Chinese cabbage was soaked in aqueous solutions of Cu(NO₃)₂, CuSO₄, and Cu(CH₃COO)₂, followed by pyrolysis, which resulted in carbona- ceous materials with distinct structural and electrochemical characteristics. Raman spectroscopy and...