Bear-trap sensing of somatostatin via split aptamers and atomic force microscopy

A split aptamers-based aptasensor is applied to peptide sensing using atomic force microscopy (AFM). Somatostatin (SST) is targeted as a model peptide. The aptamer against SST is split, and each part is chemically modified with a probe or a chip. Hybridized aptamers can detect label-free SSTs and monitor changes in their concentration from 2 nM to 2000 nM as an index of interactive force. The change in an interactive force could be firstly evaluated via Hill model. Additionally, the analysis based on the fitting enables clarification of the differences in hybridization and in interaction, as well as an estimation of the number of SSTs. The proposed sensing system can promote peptide sensing based on the use of an aptasensor.