Alzheimer’s disease (AD) is a devastating neurodegenerative disorder that affects over 10% of the global population aged 65 and above. Despite concerted global efforts, AD patients can only be diagnosed after the onset of symptoms, relying on neuropsychological tests and neuroimaging. However, the changes in biomarker levels associated with Aβ deposits and tau tangles precede the appearance of cognitive symptoms, making accurate measurements of AD core biomarkers crucial for identifying asymptomatic patients and predicting disease progression.
In response to this challenge, researchers have been working tirelessly to develop novel AD biomarker-targeting sensor platforms that boast exceptional sensitivity and high accessibility. This review provides a comprehensive overview of recent advances in optical and electrical sensing of core AD biomarkers in clinically relevant fluids, such as cerebrospinal fluid and human blood.
Optical Sensing: A Beacon of Hope
Optical sensing techniques have emerged as a promising approach for detecting AD biomarkers. Recent studies have demonstrated the potential of surface-enhanced Raman spectroscopy (SERS), fluorescence spectroscopy, and optical fiber sensors to detect Aβ and tau proteins in cerebrospinal fluid and blood. These techniques offer high sensitivity, selectivity, and multiplexing capabilities, enabling the simultaneous detection of multiple biomarkers.
Electrical Sensing: A Complementary Approach
Electrical sensing techniques, such as electrochemical impedance spectroscopy (EIS) and field-effect transistor (FET) sensors, have also shown great promise in detecting AD biomarkers. These methods offer high sensitivity, rapid detection, and low cost, making them attractive for point-of-care applications.
Challenges and Future Strategies
Despite the significant progress made in AD biomarker sensing, several challenges remain to be addressed. These include the need for improved sensitivity and specificity, standardization of sensing platforms, and validation of biomarkers in large-scale clinical trials. To overcome these hurdles, future strategies should focus on:
- Multidisciplinary collaborations: Integrating expertise from materials science, engineering, biology, and medicine to develop innovative sensing platforms.
- Standardization and validation: Establishing standardized protocols for biomarker detection and validation in large-scale clinical trials.
- Point-of-care applications: Developing portable, user-friendly sensing devices for early diagnosis and disease monitoring in clinical settings.
- Personalized medicine: Using sensing platforms to identify biomarker profiles for individual patients, enabling personalized treatment and disease management.
The development of novel AD biomarker-targeting sensor platforms has the potential to revolutionize the diagnosis and management of Alzheimer’s disease. By addressing the current challenges and implementing future strategies, we can translate these sensing techniques into clinical analytic platforms, enabling early diagnosis and disease progression prediction. This critical step forward will ultimately improve the lives of millions of people worldwide affected by this devastating disease.
