Chemical sensing platforms for detecting trace-level Alzheimer's core biomarkers

Abstract

<p>This review provides an overview of recent advances in optical and electrical detection of Alzheimer's disease biomarkers in clinically relevant fluids.</p>

Plasmonic Nanoparticles as Optical Sensing Probes for the Detection of Alzheimer’s Disease

“…To provide a sensitive and selective detection, the bioreceptor should exhibit a high affinity or dissociation constant (Kd) towards the specific analyte. It has been reported that bioreceptors with Kd ~10 −15 M can recognize analytes down to fM concentration level [40]. In this context, the most well-established bioreceptors with high dissociation constants are antibodies (10 −8 -10 −12 M) [64] and aptamers (10 −6 -10 −12 M) [40].…”

“…It has been reported that bioreceptors with Kd ~10 −15 M can recognize analytes down to fM concentration level [40]. In this context, the most well-established bioreceptors with high dissociation constants are antibodies (10 −8 -10 −12 M) [64] and aptamers (10 −6 -10 −12 M) [40]. Although antibodies are widely used as sensing platforms, some disadvantages have been described such as low stability and higher lot-to-lot variations; on the other hand, aptamers are a promising alternative due to their features as high stability at room temperature, low cost, ease of synthesis, among others [40].…”

“…Optical biosensors are the most common sensors containing a bioreceptor element integrated with an optical transducer system. Thus, these optical biosensing platforms measure the interaction between the target analyte and the bioreceptor through changes in Raman signals, absorbance, fluorescence, LSPR, or color changes [40]. For example, the conventional enzyme-linked immunosorbent assay (ELISA) test is a type of optical sensor based on absorption and/or fluorescence, with LODs in the pM range, however, several of the plasmonic biosensors described in the following subsections have achieved sensitivities at fM level.…”

“…The localized plasmons in metal NPs are formed by coupling with photons at certain wavelengths. Thus, the signal transduction mechanism of LSPR platforms is based on their sensitivity to local refractive index changes (as a shift of extinction wavelength) near the surface of -size and -shape-controlled AuNPs and AgNPs after specific recognition between a biomarker and a recognition element [40,104]. So far, some studies have reported the use of LSPR for the detection of AD in fluids.…”

Stem Cell Therapies in Alzheimer’s Disease: Applications for Disease Modeling

“…Typical features are early neuroinflammation, learning and memory impairments, followed by complex attention, visuospatial function, executive function, praxis, language, gnosis, behavior, and/or social impairment (Scheltens et al, 2016;Arvanitakis et al, 2019;Lempriere, 2019). In recent years, although significant progress has been made in clarifying key aspects of the biology, the etiological mechanisms of AD are still far from being fully understood (Jafari et al, 2020;Kim et al, 2020). New treatment strategies and drugs attempting to slow or halt cognitive This article has not been copyedited and formatted.…”