A dual-screening electrochemiluminescent aptasensor based on a mesoporous silica nano-sieve for specific detection of amyloid-β monomer

• DOI: 10.1016/j.snb.2021.131065
• Publication Date: 2021-11-07T22:19:17Z
• Authors: Rong Tan; Yueju Wang; Xiaona Mi; Huiling Li; Yifeng Tu
• Keywords: Sieve (category theory)

Abstract Amyloid β-protein (Aβ) aggregation in the brain is a closely related symptom of Alzheimer’s disease (AD), while Aβ in blood might be a more accessible peripheral biomarker to predict AD much earlier due to its abnormal fluctuation. However, when developing an aptasensor for Aβ detection, the specificity of the sensor will be impaired by Aβ aggregates such as Aβ oligomers or fibers because they have the same unit of recognition. Herein, a novel dual-screening sensing strategy based on specific recognition by aptamers and nano-sieving by a mesoporous silica membrane (MSM) with electrochemiluminescence (ECL) as the output signal is reported, in which the MSM achieves a size-screening effect to eliminate the influence of those macromolecules, assisting the specificity screening of the aptamer. The ECL signal is determined by the steric hindrance of the specifically captured Aβ on the aptamer in the nanochannels of the MSM towards the probe (luminol), affording a highly sensitive and specific detection ability for Aβ in complex matrices. In general, this work develops an ECL sensor that integrates aptamer recognition with size-selective separation for blood Aβ detection, which positively helps to monitor the occurrence and development of AD.