Efficient immobilization of aptamers on the layered double hydroxide nanohybrids for the electrochemical proteins detection

Despite the use of layered double hydroxides (LDH) in different electrochemical (bio)sensors, the construction of aptasensors using LDH- based surfaces was not reported to the best of our knowledge. This may be due to the lack of a suitable linker to attach aptamers to the LDH-modified surface. LDH-based aptasensors are established here as very sensitive and reliable devices in serum and cerebrospinal fluid (CSF) analysis. 5'-NH2 DNA aptamer probes were immobilized on the LDH-based surfaces in a vertical conformation without any linker materials. Due to the low electron conductivity of the LDH, carbon nanotubes (CNT) with high electronic conductivity and high surface area were combined with LDH. Thrombin was used as a model protein for aptasensing. The sen sor shows a linear range of 0.005-12,000 pmol L-1 and a limit of detection of 0.1 fmol L-1. Moreover, the aptasensor was used for the sensing of thrombin in CSF and scrum samples acquired from both healthy and patients with different disease. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

LDH-based aptasensors have been established as sensitive and reliable devices for serum and cerebrospinal fluid (CSF) analysis, with 5'-NH2 DNA aptamer probes immobilized on the surfaces in a vertical conformation without any linker materials. The combination of carbon nanotubes with LDH has helped enhance electronic conductivity for improved sensing of proteins like thrombin.