Citrate-capped gold nanoparticles as colorimetric sensors for amyloid ßpeptide (1-42) targeting in liquid samples

Alzheimer’s Disease (AD) is a severe neurodegenerative disorder, marked by cognitive decline, memory loss, and behavioral skill impairment. Actually, amyloid β-peptide 1-42 (Aβ (1-42)) is one of the main recognized AD biomarkers. The possibility of detect Aβ (1-42) at very low concentration in different biological fluids allow the early-stage diagnosis, which currently represents the most efficacious AD therapy. To date, optical detection techniques have gained rising attention for the development of Aβ (1-42) sensors based on the analyses of liquid samples. In this context, optical metallic nanoconstructs are promising alternative for the development of novel rapid and low-cost methods for the targeting of Aβ (1-42) in fluids. Herein, diagnostic platforms are based on gold citrate-capped nanoparticles (AuNPs), whose aggregation can be modulated by the presence of the target biomarker as a function of its concentration and has been smartly used to develop colorimetric assays. The performances of this novel system are validated for specific detection of synthetic ß-amyloid peptide (Aß) in liquid fluids with high selectivity and sensitivity down to the nanomolar.