Fluorescence Immunochromatographic Assay For Quantitatively And Simultaneously Detection Of Neuron Specific Enolase And Carcinoembryonic Antigen

Lung cancer is one of the most common and serious malignancies.Simultaneous analysis of neuron specific enolase(NSE)and carcinoembryonic antigen(CEA)can in significant measure improving the sensitivity and specificity for lung cancer diagnosis.In this study,we developed a quantum dots(QDs)/quantum dot beads(QBs)based immunochromatographic assay.Combining with a portable test strip reader our lab developed,this assay could achieve quantitative and simultaneous detection of NSE and CEA.Easy operation,short analysis time and low cost,this method have great potential application in early lung cancer diagnosis.In this paper,the QDs/QBs based immune fluorescent probes were developed using carbodiimide EDC/NHS method.The corresponding immunochromatography test strips(ICTS)were also developed for NSE and CEA detection.The research characterized the nano materials and immune probes,and obtained the optimal coupling rate between the two labeling materials and antibodies through bicinchonininc acid albuminometry.To make the best performance possible,the type of nitrocellulose(NC)membrane in the test zone,order of the test line 1(T 1)and test line 2(T 2),incubating time between antigens and probes,concentration of Tween-20 in conjugating pad treating fluid and pretreatment of the serum sample had been optimized during the assembly process of the ICTS.QBs based ICTS: the test results had a logarithmic linear correlation with the analyte concentrations for CEA and NSE with the ideal limitation of 0.0378ng/m L and 0.0426ng/m L respectively,which both meet the clinical detection requirement.The test result of 70 positive and 30 negative serum samples showed that the ICTS had sensitivity of 99% and 97% for CEA and NSE,while the specificity was 97% and 100% respectively.Meanwhile,cross-reactivity evaluation of carbohydrate antigen 72-4(CA72-4),prostate specific antigen(PSA)and alphafetoprotein(AFP)indicated the high specificityof the ICTS showing the great potential application in early lung cancer diagnosis.QDs based ICTS: the detection limit were 1 ng/m L and 100 ng/m L for CEA and NSE respectively.The detection of NSE was below the clinical detection requirement(24 ng/m L).Finally,the result of experiment recommended that the QBs was the ideal labeling material for clinical sample detection.