Aptasensing of beta-amyloid (A beta((1-42))) by a 3D-printed platform integrated with leaf-shaped gold nanodendrites

In this study, beta-amyloid (A beta((1-42))), an essential biomarker for diagnosing Alzheimer's disease (AD), was detected via an electrochemical aptasensing platform. Here, an innovative signal transducer was developed using a CO2 laser-ablated 3D-printed electrode modified with leaf-shaped gold nanodendrites (LSG NDs, mean diameter: similar to 92 nm), which could provide an efficient interface for immobilizing aptamer strands. The modified electrode with LSG NDs exhibited an enhancement in its electrochemically active surface area about 7 times, compared with the bare electrode. This modification showed that the size, morphology, and distributions of LSG NDs in amplifying electrochemical signals might effectively provide a highly sensitive infrastructure for analyte detection. The strands of a thiol-functionalized aptamer sequence interacted with the gold surface, which created an optimized biointerface to detect A beta((1-42)) in a linear range from 0.1 pg mL(-1) to 10 ng mL(-1) (limit of detection (LOD): 84 fg mL(-1), (S/N = 3)). The developed aptasensor confirmed satisfactory stability, desired reproducibility and regeneration, and minimal impact of interfering agents. In addition, the application of this aptasensor was monitored via an assay of spiked analyte concentrations in 20 samples, including cerebrospinal fluid (CSF) and human serum.

Automated summary

This study successfully detected beta-amyloid (A beta((1-42))), an important biomarker for diagnosing Alzheimer's disease (AD), using an electrochemical aptasensing platform. An innovative signal transducer, a CO2 laser-ablated 3D-printed electrode modified with leaf-shaped gold nanodendrites (LSG NDs), was developed to provide an efficient interface for immobilizing aptamer strands. The modified electrode with LSG NDs showed a significant enhancement in electrochemically active surface area, amplifying electrochemical signals and providing a highly sensitive infrastructure for analyte detection. The developed aptasensor demonstrated stability, reproducibility, regeneration, and minimal interference from other agents, and the application of this aptasensor was successfully monitored in spiked analyte concentrations in 20 samples including cerebrospinal fluid (CSF) and human serum.