Aptamer/antibody-based and amplified lateral flow assays for detection of vascular endothelial growth factor 165

Early screening of serious diseases can significantly improve survival rates and quality of life, and potable and user-friendly analytical devices are conducive to point-of-care testing (POCT). In this study, a lateral flow assay (LFA) for colorimetric analysis of a significant early cancer biomarker, vascular endothelial growth factor 165 (VEGF165), was designed based on an “antibody-VEGF165-aptamer” sandwiched structure. The aptamer for VEGF165 was introduced to overcome the bottleneck, namely, high cost and limited types of antibodies of VEGF165. In addition, the sensitivity was substantially increased by cascading an in-situ gold growth-mediated signal amplification strategy (ISGGS), and as low as 0.12 ng/mL VEGF165 can be detected. Based on the universal LFA-ISGGS principle, test strips were fabricated for detecting another biomarker (cardiac troponin I, cTnI). Moreover, one test strip with dual detection channels was successfully obtained for simultaneous detection of VEGF165 and cTnI, further confirming the universality of our LFA-ISGGS platform, and indicating that the platform holds great potential for bed diagnosis of serious diseases in the future.