This report presents an innovative enzyme-free electrochemical sensor for the selective detection of lactic acid (LAC). Here, a unique integration of the covalent organic framework derived from benzene-1,4-diboronic acid (COF) and a molecularly imprinted polymer (MIP) was reported for LAC detection. Integrating this COF, which features a favorable chemical structure and high surface area, with an MIP derived from a conductive polymer (polypyrrole) yields excellent sensor performance. In the sensing process, the interaction between the hydroxyl group of LAC and the hydroxyl groups of COF can significantly enhance sensor performance. The proposed sensor demonstrated a low limit of detection (LOD = 0.16 μM), a broad linear concentration range (0.50–5500 μM), excellent stability, and high selectivity. In cancer patients, LAC levels serve as a biomarker for detecting different stages of the disease. The developed sensor in this study demonstrates the potential for LAC detection as a cancer biomarker in real human plasma samples.
