Clickmers are chemical modified aptamers representing an innovative reagent class for developing binders for biomolecules with great impact on therapeutic and diagnostic applications. To establish a novel layer for screening...

The click-SELEX procedure enables the identification of nucleobase-modified aptamers in which chemical entities are introduced by a copper(I)-catalysed alkyne-azide ‘click’ reaction. Here we report on the impact of modified nucleobases...

Herein, a simple colorimetric aptasensor based on unmodified gold nanoparticles (AuNPs) has been developed for quantifying pancreatic polypeptide (PP), a peptide hormone associated with nonfunctional neuroendocrine pancreatic tumor (NF-PNET). First, several PP-specific aptamers have been screened by systematic evolution of ligands by exponential enrichment. The generated aptamers showed specificity and affinity higher than those reported so far. The sensing platform was constructed based on the optical properties of AuNPs as well as the adsorption of single-stranded DNA aptamers. The high sensitivity of the developed aptasensor was achieved by optimizing the sensing conditions, including salt tolerance, time of reaction, and optimal aptamer concentration. The developed aptasensor showed a wide linear dynamic range (1–60 nM) with a limit of detection of 521 pM. Furthermore, the performance of the aptasensor was evaluated for the detection of PP in human serum and showed recovery values ranging between 92.4 and 93.9%. Therefore, the presented colorimetric aptasensor has a great potential in the diagnosis of NF-pNETs.