Recent Advances in the Application Peptide and Peptoid in Diagnosis Biomarkers of Alzheimer’s Disease in Blood

Abstract

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases with irreversible damage of the brain and a continuous pathophysiological process. Early detection and accurate diagnosis are essential for the early intervention of AD. Precise detection of blood biomarkers related to AD could provide a shortcut to identifying early-stage patients before symptoms. In recent years, targeting peptides or peptoids have been chosen as recognition elements in nano-sensors or fluorescence detection to increase the targeting specificity, while peptide-based probes were also developed considering their specific advantages. Peptide-based sensors and probes have been developed according to different strategies, such as natural receptors, high-throughput screening, or artificial design for AD detection. This review will briefly summarize the recent developments and trends of AD diagnosis platforms based on peptide and peptoid as recognition elements and provide insights into the application of peptide and peptoid with different sources and characteristics in the diagnosis of AD biomarkers.

Microarray Chip-Based High-Throughput Screening of Neurofilament Light Chain Self-Assembling Peptide for Noninvasive Monitoring of Alzheimer’s Disease

“…A variety of peptide-based biosensors have shown potential for detecting blood biomarkers due to their pg-level detection sensitivity . Common techniques for the development of self-assembling peptides include addition of Lys-Leu-Val-Phe-Phe (KLVFF) peptide motifs after peptide synthesis based on material synthesis and phage display technology. , However, the binding specificity based on this self-assembly strategy is uncertain, which might decrease or increase the binding effects.…”

A label-free electrochemical immunosensor based on Au-BSN-rGO for highly-sensitive detection of β-amyloid 1–42

“…All electrochemical tests were carried out in 0.5 M [Fe(CN) 6 ] 3−/4− and 0.5 M KCl solutions. The cyclic voltammetry (CV) scan rate was 50 mV and the scan range was from 0.6 V to −0.2 V. The electrochemical impedance spectroscopy (EIS) was performed with the frequency from 0.1 Hz to 10 6 Hz, and the initial potential was 0.3 V. The differential pulse voltammetry (DPV) measurement was performed with the voltage ranging from 0 V to 0.5 V, the pulse amplitude was 50 mV, and the pulse period was 500 ms.…”

“…5 Among them, the accumulation of Aβ will lead to Aβ plaques, which is the most important pathological feature of AD. 6 Aβ including two isoforms of less neurotoxic Aβ 1-40 and neurotoxic Aβ 1-42 are formed due to the abnormal hydrolysis of the amyloid precursor protein (APP), 7,8 in which Aβ 1-40 is soluble, while Aβ 1-42 tends to accumulate and form Aβ plaques. 9 Therefore, Aβ 1-42 is considered to be the most reliable biomarker for diagnosing AD.…”

Fluorescent Sensing Platforms for Detecting and Imaging the Biomarkers of Alzheimer’s Disease

“…Normally, the production and clearance of Aβ peptides should be balanced, but in AD patients, increased production and decreased clearance of Aβ lead to abnormal extracellular accumulation of Aβ40 and Aβ42 peptides. Since the concentration of Aβ40 in CFS is ten times that of Aβ42, the concentration of Aβ40 does not change significantly during the process of AD, and the ratio of Aβ42/Aβ40 is more accurate than that of a single indicator [37]. The abnormally aggregated Aβ42 monomer self-assembles into soluble Aβ oligomers, which then form fibrils and plaques that eventually lead to tau pathology and subsequent neuronal dysfunction [38].…”