Electrochemical Chip for the Alzheimer’s Associated miRNA PCR-Free Detection

Alzheimer’s disease (AD) is the most common worldwide neurodegenerative disorder with a tremendous socio-economic impact on our society. There is a lack of easy, inexpensive, and non-invasive practices that would allow for early diagnosis. Growing evidence indicates that dysregulation in microRNAs (miRNAs) function in various aspects of AD pathogenesis and changes in specific blood circulating miRNA levels could be used as diagnostic biomarkers, which is the case of the circulating miR-146a. In this work, we presented an electrochemical strategy for AD miRNA biomarker detection without the need to amplify the genetic material by PCR. A gold working electrode (WE) has been modified with an array of thiol-modified oligonucleotide capture probes for miRNA detection and quantification by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The effectiveness of the chemical protocol used for the WE surface functionalization has been validated by contact angle (CA) analysis. As a future perspective, electrochemical layouts having different combinations of 3 microfabricated electrodes have been designed for Point-of-Care (PoC) chip integration.