Electrochemical immunoplatform to help managing pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the solid tumor with the worst prognosis, representing today the third cause of cancer-related deaths in developed countries and expected to be the second in 2030. Today, CA19-9 remains the only clinically used marker for management of PDAC (FDA-approved as a disease monitoring marker). This work reports a disposable amperometric immunoplatform for the determination of CA19-9. The immunoplatform skilfully combines the advantages of magnetic microsupports (MBs) for implementation of the immunoassay and amperometric transduction on screen-printed carbon electrodes (SPCEs). The method involves the preparation of sandwich immunocomplexes enzymatically labeled with the enzyme horseradish peroxidase (HRP) on the MBs and uses a detection antibody conjugated to HRP. Once the HRPlabeled sandwich immunocomplexes-bearing MBs were trapped on the SPCE surface, the variation of the cathodic current was measured in the presence of H2O2 and hydroquinone (HQ), which was directly proportional to the concentration of CA19-9. Under the optimized experimental conditions, the immunoplatform allowed the amperometric determination of CA19-9 standards over the 5.0 to 500 U mL-1 concentration range, with a limit of detection (LOD) value of 1.5 U mL-1 in 1 h. The method exhibits good reproducibility and selectivity and the magnetic immunoconjugates shows a good storage stability. The immunoplatform was applied to the determination of CA19-9 in serum samples of a medium-sized cohort (22 individuals) of healthy subjects and patients diagnosed with PDAC. The obtained results demonstrated the immunoplatform ability to discriminate both types of individuals within 1 h after sample dilution. The developed immunoplatform represents an improvement in terms of cost, applicability and accessibility compared to the ELISA-based techniques currently used in the clinic.

Automated summary

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths in developed countries and predicted to be the second leading cause in 2030. A disposable amperometric immunoplatform for the determination of CA19-9 has been developed in this study. The immunoplatform combines magnetic microsupports (MBs) for immunoassay implementation and amperometric transduction on screen-printed carbon electrodes (SPCEs). The immunoplatform showed good reproducibility, selectivity, and storage stability, and was able to differentiate healthy subjects from PDAC patients within 1 hour. It represents an improvement in terms of cost, applicability, and accessibility compared to current ELISA-based techniques.