Development of Dual-Aptamers for Constructing Sandwich-Type Pancreatic Polypeptide Assay.

Pancreatic polypeptide (PP) is a specific biomarker of nonfunctional pancreatic neuroendocrine tumors (NF-pNETs). Clinical significance of PP inspires researchers to make great efforts in developing sensitive and specific sensors. However, there is no existing biosensor for detecting PP that combines facility and functionality. Addressing this challenge, a pair of aptamers which could be used to develop a sandwich assay for PP is reported. First, several high affinity aptamers are screened through graphene oxide-based SELEX, and appropriate dual-aptamers which could bind to different epitopes of PP are identified through fluorescence assays. Then the feasibility of the dual-aptamers for constructing the sandwich assay is validated via dynamic light scattering. This sandwich assay shows considerable sensitivity and specificity. The above results imply that the dual-aptamers have the potential toward developing novel sensors for PP in clinical samples.