Rapid Biosensor Detects Pancreatic Cancer Biomarker for Early Detection

Conventional laboratory assays for tumor markers require specialized infrastructure and longer processing times, limiting access. A streamlined approach that works directly with blood could help address these diagnostic gaps. Researchers now report an electrochemical biosensor that detects the pancreatic cancer biomarker CA19-9 at low concentrations in routine blood samples.

At the University of São Paulo’s São Carlos Institute of Physics (IFSC-USP), investigators developed an electrochemical sensor designed to identify carbohydrate antigen 19-9 (CA19-9), a biomarker molecule associated with pancreatic cancer. The device is intended to provide a simpler, more affordable alternative to conventional testing. The researchers' findings could enable detection of the biomarker in early stages of disease using blood samples.

The biosensor operates via antigen–antibody recognition on the device surface, functioning in a lock‑and‑key manner. Specific anti–CA19-9 antibodies immobilized on the electrode capture target molecules in the sample. This binding event changes charge distribution at the electrode interface, which the device converts into a measurable capacitance signal. Results are interpreted against a pre-established calibration curve to estimate CA19-9 concentration.

In a study conducted by the team, testing on 24 blood samples from patients at different disease stages and from a control group yielded results that were statistically similar to traditional assays. The article notes that CA19-9 is frequently monitored with enzyme-linked immunosorbent assay (ELISA), which requires well-equipped laboratories, skilled personnel, and longer processing times compared with biosensor-based methods. The new approach is presented as a means to detect very low concentrations of the biomarker in a rapid, accessible format.

Findings are published in ACS Omega (2026) under the title “Supramolecular PDDA/PEDOT:PSS Biosensor for Early Pancreatic Cancer Detection via CA19-9: Clinical Validation on Human Blood Samples.” The group is also developing two additional sensors with different architectures and detection mechanisms and plans to analyze blood, saliva, and urine provided by the Hospital of Clinics of the Ribeirão Preto School of Medicine. In parallel, the researchers are applying machine learning to integrate multi-sample outputs into a “bioelectronic tongue” capable of pattern recognition, prediction, and error correction.

“In its early stages, pancreatic cancer is asymptomatic, which means the disease is often identified too late. That's also why pancreatic cancer is one of the deadliest forms of cancer. So much so that in advanced cases, the five-year survival rate is only 3%. The idea of developing this cheap and simple biosensor stems from the principle of providing access to screening for the disease,” said Débora Gonçalves, professor at IFSC-USP and project coordinator.

“The higher the concentration of CA19-9, the greater the variation detected by the sensor. In about ten minutes, the system compares the result with a pre-established calibration curve, estimating the amount of the protein in the blood. This allows us to identify very low concentrations of CA19-9, enabling the early diagnosis of the disease in a fast and accessible way,” said Gabriella Soares, doctoral student in materials engineering at USP and first author of the study.

Related Links
IFSC-USP