Simultaneous detection of gastric cancer screening biomarkers plasma pepsinogen I/II using fluorescent immunochromatographic strip coupled with a miniature analytical device

Pepsinogen I (PG I) and pepsinogen II (PG II) are gastric disease-associated proteins that have been utilized as biomarkers for gastric cancer screening. However, the current methods for detecting PG I and PG II can barely satisfy the needs of mass screening, especially in remote areas. In this study, a rapid and sensitive fluorescent immunochromatographic test strip with a miniature analytical device (20.0 cm × 18.9 cm × 11.2 cm, 2.4 kg) was developed for the simultaneous determination of PG I and PG II in one sample in a single assay, which is promisingly suitable for the mass screening of gastric cancer. Under the optimum conditions, PG I and PG II concentrations as low as 2.6 ng/mL and 1.0 ng/mL could be detected in 15 min with only 7.5 μL plasma specimen, and no cross-reactivity was observed. The detection range was linear over 10.0–210.0 ng/mL for PG I and 3.0–63.0 ng/mL for PG II. The immunosensor also demonstrated high recoveries (93.6–110.8% for PG I and 95.4–110.4% for PG II) with low coefficient of variation (CV) (4.8–8.1% for PG I and 6.6–11.7% for PG II) when testing actual human plasma. The analyses by the proposed assay correlated well with those by ELISA of 30 spiked samples. The assay was finally applied to 30 clinical samples, and the results showed its clinical significance for the early screening of gastric cancer. Therefore, the assay proposed in this study provides a rapid, sensitive, and simultaneous detection strategy in the pepsinogen test, and the results indicated its potential capacity in the mass screening of gastric cancer.