Fluorescent aptasensor based on target-induced hairpin conformation switch coupled with nicking enzyme-assisted signal amplification for detection of beta-amyloid oligomers in cerebrospinal fluid

Mikrochim Acta. 2025 Jan 13;192(2):70. doi: 10.1007/s00604-024-06943-8.

Abstract

A fluorescent aptasensor was developed based on target-induced hairpin conformation switch coupled with nicking enzyme-assisted signal amplification (NESA) to detect the oligomeric form of ß-amyolid peptide (AβO) in cerebrospinal fluid. The hairpin DNA probe (HP) was specifically designed to recognize AβO. When AβO is present in the sensing system, it induces an HP conformational switch and triggers the NESA reaction. After evaluating the parameters of the aptasensor system, we selected Hairpin10, which has a 10-nucleotide extended sequence, as the hairpin sequence that interacts with AβO. The quantitative linear range of the proposed aptasensor is from 11.3 to 113 ng mL-1 in artificial cerebrospinal fluid (aCSF), and the detection limit was 7.29 ng mL-1. The present work realized the assay of AβO in aCSF with satisfactory quantitative results.

Keywords: Alzheimer`s disease; Aβ oligomers; Fluorescent aptasensor; Nicking enzyme-assisted signal amplification; Target-induced hairpin conformation switch.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides* / analysis
  • Amyloid beta-Peptides* / cerebrospinal fluid
  • Amyloid beta-Peptides* / chemistry
  • Aptamers, Nucleotide* / chemistry
  • Biosensing Techniques* / methods
  • DNA Probes / chemistry
  • DNA Probes / genetics
  • Fluorescent Dyes* / chemistry
  • Humans
  • Inverted Repeat Sequences
  • Limit of Detection*
  • Nucleic Acid Conformation
  • Spectrometry, Fluorescence / methods

Substances

  • Aptamers, Nucleotide
  • Amyloid beta-Peptides
  • Fluorescent Dyes
  • DNA Probes