Functionalized graphene-based electrochemical array sensors for the identification of distinct conformational states of Amyloid Beta in Alzheimer's disease.

Aβ oligomers have been widely accepted as significant biomarkers for Alzheimer's disease (AD) detection, monitoring, and therapy since they are highly correlated with AD development. In this work, an electrochemical array-based sensing platform was successfully built using a group of functionalized graphene with different physicochemical features. Since the electro-insulated Aβ peptide species severely interfered with the electron transport on the electrode surface, the presence of Aβ led to a significant change in the electrochemical impedance signal. The resulting variety of the impedance was then classified and processed by linear discriminant analysis. The constructed sensing platform can discriminate different Aβ forms, the mixture of various Aβ forms, and different ratios of Aβ42 to Aβ40 with 100% accuracy by only the combination of dual probes. Furthermore, it also exhibited excellent performance for screening Aβ inhibitors and metal chelators. The strategy utilizes the infinitesimal general discrepancy instead of specific biomarker recognition, exhibiting the advantage of no requirement to know the exact information about the specific ligand and receptor in advance, which is promising to be widened for the other biosensing detection fields. • A facile functionalized graphene-based electrochemical array sensor was successfully constructed. • The prepared sensing platform could discriminate different Aβ forms, the mixture of various Aβ forms, and different ratios of Aβ42 to Aβ40 in buffered solutions as well as in complex body fluid environments. • 100% identification through the combination of dual probes was achieved, indicating the super diagnostic capacity of the sensor array. • The strategy utilizes the infinitesimal general discrepancy instead of specific biomarker recognition. [ABSTRACT FROM AUTHOR]