Molecularly imprinted fluorescence sensor based on Fe3O4/CDs@MIPs for detecting the gastric cancer marker p-Hydroxybenzoic acid

With the rapid development of metabolomics, p-Hydroxybenzoic acid in urine has been identified as a crucial biomarker for the early detection and screening of gastric cancer. In this study, we designed and synthesized a novel magnetic hollow carbon dot molecularly imprinted fluorescence sensor (Fe₃O₄/CDs@MIPs) to achieve high sensitivity and selectivity detection of this biomarker. The incorporation of Fe₃O₄ nanoparticles into the sensor significantly improved its recognition capability and analytical performance. The fluorescence sensor exhibited a strong linear response within the concentration range of 0–100 μmol/L, with an impressive detection limit of 0.37 μmol/L. The sensor demonstrated excellent specificity, showing minimal interference from common cations, anions, amino acids, and structural analogs, underscoring its high selectivity for p-Hydroxybenzoic acid. In practical applications, spike recovery experiments conducted on urine samples from both gastric cancer patients and healthy individuals revealed recovery rates ranging from 95.00 % to 106.67 % and relative standard deviations between 0.76 % and 2.80 %. These results confirmed the sensor’s outstanding accuracy, reproducibility, and stability. Overall, the Fe₃O₄/CDs@MIPs sensor provides a robust, non-invasive instrument for detecting gastric cancer biomarkers in urine, offering significant potential for early diagnosis and monitoring of gastric cancer.