In a study published in Nature Nanotechnology, a research team led by Prof. WU Haichen from the Institute of Chemistry of the Chinese Academy of Sciences, and Prof. LIU Lei from Xihua University, developed a nanopore-based enzyme-linked immunosorbent assay (NELISA) for cancer biomarker detection.

Early diagnosis of cancer is crucial for improving patient prognosis and significantly reducing mortality rates. The detection of cancer biomarkers in body fluid, which is less harmful to the body, is more suitable for early-stage diagnosis. ELISA is the most widely used method and is currently regarded as the gold standard for body fluid biomarker detection. 

However, conventional ELISA relies on colorimetric signal output, which limits its sensitivity and multiplexing capability, making it insufficient for ultra-early cancer detection. Althouth the performance of ELISA has been improved by technological advancements, it still falls short of meeting the stringent demands of early-stage disease diagnosis.

In this study, a peptide probe, FGXD₈⊂CB[7], which contains various enzyme-responsive groups, was employed as an enzymatic substrate in place of conventional chromogenic substrates. Following immune complex formation, an enzymatic reaction was initiated. 

In the presence of the enzyme, the responsive groups dissociated, inducing structural changes in the probe. Consequently, the probe generated distinct translocation signals when passing through the wild-type α-hemolysin nanopore before and after enzymatic cleavage. 

By statistically analyzing the frequency of current signals produced by FGXD₈⊂CB[7], researchers achieved quantitative detection of biomarker concentrations in the samples. Owing to the high signal specificity and stability of the peptide probes, the method enabled simultaneous detection of six biomarkers.

Besides, researchers applied this method to detect AFP, CEA, and CA19-9 in over 100 clinical blood samples, and achieved a concordance rate exceeding 90% with standard clinical tests, demonstrating the method’s strong potential for clinical applications.

This study develops a highly sensitive, low detection limit, and multiplexed assay with strong anti-interference capability, which integrates the strengths of ELISA and nanopore sensing technologies. It provides a powerful new tool for early cancer screening based on body fluid biomarker detection.