An electrochemiluminescence aptasensor for amyloid-β protein with signal enhancement from AuNPs/Fe-MOFs nanocomposite

The aggregation of amyloid-β protein (Aβ) into amyloid-β oligomer (AβO) and finally the deposition of amyloid-β fiber (AβF) in brain was found strongly related to Alzheimer's disease (AD). In this work, an electrochemiluminescent (ECL) aptasensor reinforced with a gold nanoparticle – iron metal orgaic framwork nano-composite (AuNPs/Fe-MOFs) was constructed for the detection of Aβ. It has the ability to specifically quantify Aβ, the precursor that had not yet been aggregated into AβO. The employed AuNPs/Fe-MOFs nano-composite in this sensor not only provided the opportunity to anchor the aptamer, but also enhanced the response to promote its sensitivity. The relative inhibition ratio of luminol ECL on this sensor was linearly related to the logarithm of Aβ concentration in the range from 0.5 to 50 pM, with a LOD at 104 fM. The aptasensor has high specificity to Aβ over its analogs and recoveries in human serum were obtained within 96.0–103.7%. The research prospectively provides a new demonstration for early diagnosis of the disease in clinic.