Alzheimer’s disease (AD) is the most common neurodegenerative disorder worldwide. Early diagnosis of AD is crucial for delaying disease progression and improving patients’ quality of life. Blood biomarkers, particularly amyloid-beta (Aβ) and Tau proteins along with their phosphorylated isoforms, show advantages such as convenient sampling, minimal invasiveness, and excellent repeatability. However, the extremely low concentrations of AD biomarkers in blood impose stringent requirements on the sensitivity, specificity, and anti-interference capability of detection methods. Optical methods provide promising analytical platforms to address these challenges in view of their intrinsic merits of high sensitivity and selectivity; rapid response; and potential for miniaturization. This review systematically summarizes the latest advances in optical methods for the detection of the two core AD blood biomarkers (Aβ and Tau), covering techniques such as colorimetry, fluorescence, chemiluminescence, surface plasmon resonance (SPR), and surface-enhanced Raman scattering (SERS). The sensing principles, design strategies, and analytical performances of these methods are discussed, with special emphasis on different signal amplification strategies. In addition, several challenges and future prospects are provided with a primary focus on single-molecule detection, insufficient sensitivity and stability, lack of validation with large clinical cohorts, and absence of standardization. This review aims to provide researchers with guidance for the rational development of high-performance optical methods to achieve early diagnosis of AD.
Ning Xia, Fengli Gao, Chu-Ye Zheng· Biosensors· 0 citations
Early diagnosis of Alzheimer’s disease (AD) can facilitate the establishment and implementation of therapeutic interventions. The currently used diagnosis methods for AD mainly include cerebrospinal fluid analysis and positron emission tomography imaging. Due to their high invasiveness, high cost, and limited accessibility, these technologies are difficult to meet the needs of large-scale population screening, grading diagnosis, and treatment, thereby limiting the popularization of early diagnosis of AD. The detection of blood biomarkers has become an important breakthrough in early screening and diagnosis of different diseases due to its non-invasive, low-cost, and easy-to-operation advantages. Recently, blood proteins such as amyloid-beta (Aβ), total and phosphorylated Tau, light chain neurofilaments (NFL), and glial fibrillary acidic protein (GFAP) have been considered promising biomarkers for the diagnosis of AD. However, there is currently no effective, minimally invasive, and easily accessible detection method for clinical diagnosis and risk prediction of AD. Electrochemical and electrical biosensors are highly sensitive, simple, fast, and cost-effective analytical tools for disease monitoring, drug development, and target detection. In this work, we comprehensively and systematically overview the progress of various electrochemical and electrical techniques for determining AD-related blood protein biomarkers, mainly including electrochemistry, electrochemiluminescence, photoelectrochemistry, quartz crystal microbalance, field-effect transistor, and organic electrochemical transistor. This work can provide guidance for researchers to develop novel electrochemical and electrical biosensors for early and accurate diagnosis of AD.
Fengli Gao, Lin Liu, Jun-Yue Li et al.· Biosensors· 0 citations