Chemical sensing platforms for Alzheimer's disease core biomarkers

Abstract

Inorganic materials with well-defined microscopic and nanoscopic morphologies have attracted great attention for various applications owing to their exotic physical and chemical properties. The thesis addresses the inorganic nanomaterials-based sensing strategies for detecting the disease-related biomarkers in human blood. Chapter 1 provides an overview of recent advances in optical and electrical sensing of Alzheimer’s disease (AD) biomarkers in clinically relevant fluids such as the cerebrospinal fluid and human blood. This chapter summarizes current challenges and future strategies for translating the sensing techniques discovered in the academic laboratories into clinical analytic platforms for early diagnosis of AD. Chapter 2 describes the bismuth vanadate (BiVO4)-based photoelectrochemical (PEC) platform for detecting the total tau proteins. The platform is constructed by incorporating molybdenum dopant and iron oxyhydroxide (FeOOH) ad-layer into the BiVO4 photoelectrode and employing a signal amplifier formed by horseradish peroxidase-triggered oxidation of 3,3-diaminobenzidine. Chapter 3 presents a bias-free PEC detection system based on three-dimensional metallic woodpile nanostructures. The 5-layered platinum-based woodpile electrode exhibits high oxygen reduction activities due to the large electrochemical active surface area and the effective electron transfer properties. An unbiased PEC detection system is accomplished by combining a water-oxidizing, FeOOH deposited BiVO4 photoanode with the platinum woodpile cathode. Chapter 4 discusses the densely aligned carbon nanotubes (CNTs) sensor arrays for clinically accurate detection of multiple AD core biomarkers in human plasma. The closely packed and unidirectionally aligned CNT sensor array exhibits high precision, sensitivity, and accuracy, evidenced by a low coefficient of variation (<6%), a femtomolar-level limit of detection, and a high degree of recovery (>93.0%).