Visualized chemiluminescence immunoassay for simultaneous detection of multiple lung cancer markers based on...

Lung cancer ranks as the most prevalent form of cancer. Early detection and diagnosis can lower death rates, and variations in tumor markers can help assess cancer risk. In this work, a glow-type chemiluminescent (CL) hydrogel SCG-Co²⁺-luminol was synthesized by a simple approach, and this hydrogel was integrated with a 3D microfluidic paper-based analytical device (3D μPAD) to develop a visual biosensor for identifying multiple lung cancer markers. The prepared SCG-Co²⁺-luminol can produce strong CL signal after reacting with H₂O₂, and the CL time can last more than 60 min because of its porous structure. The 3D μPAD is designed with six detection areas and can simultaneously identify two lung cancer markers, NSE and CEA, based on the concept of spatial resolution. Using the hydrogel as the sensing interface and the 3D μPAD as the detection platform, a blue CL signal was emitted upon H₂O₂ injection, and the luminescence image was captured by a smartphone. Image J software was used to process the gray values of the images, demonstrating a clear linear relationship between the concentrations of NSE and CEA concentrations and the CL intensity. The linear range of the immunoassay is 0.1-10000 pg/mL, with detection limits for NSE and CEA at 0.032 pg/mL and 0.036 pg/mL, respectively. Finally, the proposed visualized CL immunoassay was successfully employed to determine NSE and CEA in real samples. Overall, the fabricated method has the merits of rapid detection, high sensitivity, and portability, making it highly promising for multi-component detection and analysis in lung cancer.