Construction Of An Electrochemical Immunosensor For Detection Of The Tumor Marker CA242

Electrochemical immunosensors have been widely used in clinical,environmental,and food hygiene fields.The improvement of analytical sensitivity and accuracy has been a key problem in the development of electrochemical immunoassays.As a tumor marker,carbohydrate antigen 24-2?CA242?is a highly accurate and specific diagnostic indicator for monitoring pancreatic and colorectal cancers.The goal of this study was to create a novel label-free electrochemical immunosensor using a nanocomposite glassy carbon electrode for the detection of CA242.Graphene oxide?GO?and polyvinyl pyrrolidone were chosen as the dopants for the preparation of a high-performance reduced-GO-gold-palladium?rGO-Au-Pd?nanocomposite.RGO-Au-Pd was characterized using X-ray diffraction and transmission electron microscopy,revealing that the material had superior electrochemical redox activity and electron transfer ability.The effects of the synthesis method,material concentration,reduction cycle,and PH were investigated to optimize the performance of the immunosensor.The prepared CA242 immunosensor displayed a wide linear range of detection from 0.001U/mL to 10000 U/mL,with a detection limit of 1.54×10^-33 U/mL and a sensitivity of 4.24?A(log₁₀C_CA242)^-1.Meanwhile,the immunosensor exhibited satisfactory reproducibility and selectivity for detection of CA242 in PBS or human serum.This study provides a new perspective for the development of ultra-sensitive electrochemical sensors.The results of this study provide a platform for the development of novel bioassays for use in early cancer diagnosis and promote the application of biosensing technology in the medical field.