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

Abstract

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.