Electrochemical sensor for the simultaneous detection of CA72-4 and CA19-9 tumor markers using dual recognition via glycosyl imprinting and lectin-specific binding for accurate diagnosis of gastric cancer

The simultaneous identification and detection of multiple tumor markers provide more pathological information for the accurate diagnosis of cancer. In this study, a novel glycosyl imprinted sensor for the simultaneous detection of tumor markers CA19-9 and CA72-4 was prepared by combining the specific recognition of the glycosylated imprinting technique and lectin-characteristic glycan chains. The imprinted membrane was fabricated by electropolymerization using the characteristic glycopeptide STn on the surface of CA72-4 and the characteristic glycopeptide SLea on the surface of CA19-9 as template molecules and 2-aminophenylboronic acid as the functional monomer. To further improve the recognition efficiency, the specific binding of lectins to glycosyl chains was introduced. Sambucus nigra agglutinin I (SNA I) was labeled with cysteine, and Maackia amurensis lectin II (MAL II) was labeled with ferrocene. According to the specific binding of SNA to the Neu5Acα2-6GalNAcα-glycan chain in STn and MAL to α2, 3 sialic acid in SLea, CA72-4, and CA19-9 could be determined, respectively, after recombination between the glycosyl groups and GIP. The sensor shows high sensitivity to CA72-4 and CA19-9 in the concentration range of 0.005–200.0 U/mL, and it has been successfully applied to the detection of CA72-4 and CA19-9 in serum samples. The sensor provides a simple, fast, and low-cost alternative for accurate diagnosis of gastric cancer.