Specific heptapeptide screened from pIII phage display library for sensitive enzyme-linked chemiluminescence immunoassay of vascular endothelial growth factor

Abstract

Abstract It is challenging to explore specific, stable and cost-effective biorecognizing elements for a wide range of applications including biosensing and nanomedicine. As the primary pro-angiogenic factor, vascular endothelial growth factor (VEGF) plays crucial roles in tumor metastasis. It holds great significance to detect VEGF in clinical diagnostics. Especially, the level of the isoform VEGF165 is usually called as the key index of many malignant tumors. Herein, phage monoclones bound to VEGF165 were selected from the pIII phage display library. Based on the phage capture assay, the phage monoclone expressing peptide LSTSPHT exhibited the best affinity and specificity against VEGF165. Then, peptide V (with the peptide sequence of LSTSPHTGGGSC) was synthesized as VEGF165 capturer to develop an enzyme-linked chemiluminescence immunoassay (ELCLIA). Under the optimal conditions, the proposed ELCLIA method showed wide linear range (10–1000 pg mL−1) and lower limit of detection (5.7 pg mL−1). Moreover, the as-developed ELCLIA was capable of detecting VEGF165 in human serum samples accurately and reproducibly. Due to its good selectivity, stability and cost-effectiveness, the VEGF165-specific peptide is prospected as a novel biointerface in sensing and tumor metastasis related diagnosis and therapy.