Alzheimer's disease is the most common neurodegenerative disease and the most prevalent form of dementia, characterized by the accumulation of amyloid β deposits and hyperphosphorylated tau proteins. These biomarkers of Alzheimer's disease can be detected using small molecule probes in combination with suitable experimental techniques. The aim of this work was a preliminary study to investigate whether the binding affinity of the selected molecular probe to the aforementioned biomarkers can be enhanced by linking the two probe units (referred to as monomers) through a suitable linker to form so-called dimers. Initially, we synthesized a free molecular probe, the monomer unit, 1-(6-((2-hydroxyethyl)(methyl)amino)naphthalen-2-yl)ethan-1-one. The 2-hydroxyethyl group in this compound was then used to couple it to a dicarboxylic linker, which was synthesized via monoesterification of N-Boc protected 7-azatetraethylene glycol with two molar equivalents of succinic anhydride. This yielded an N-Boc protected dimer, which was subsequently deprotected and its binding affinity to Aβ$_{1–42}$ fibrils was measured. The results demonstrated that the dimer exhibited approximately twice the binding affinity compared to the monomeric probe.
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