This review into recent advancements in silicon-based technology, with a particular emphasis on the biomedical applications of silicon sensors. Owing to their diminutive size, high sensitivity, and intrinsic compatibility with electronic systems, silicon-based sensors have found widespread utilization across healthcare, industrial, and environmental monitoring domains. In the realm of biomedical sensing, silicon has demonstrated significant potential to enhance human health outcomes while simultaneously driving progress in microfabrication techniques for multifunctional device development. The review systematically examines the versatile roles of silicon in the fabrication of electrodes, sensing channels, and substrates. Silicon electrodes are widely used in electrochemical biosensors for glucose monitoring and neural activity recording, while sensing channels in field-effect transistor biosensors enable the detection of cancer biomarkers and small molecules. Porous silicon substrates are applied in optical biosensors for label-free protein and pathogen detection. Key challenges in this field, including the interaction of silicon with biomolecules, the economic barriers to miniaturization, and issues related to signal stability, are critically analyzed. Proposed strategies to address these challenges and improve sensor functionality and reliability are also discussed. Furthermore, the article explores emerging developments in silicon-based biosensors, particularly their integration into wearable technologies. The pivotal role of artificial intelligence (AI) in enhancing the performance, functionality, and real-time capabilities of these sensors is also highlighted. This review provides a comprehensive overview of the current state, challenges, and future directions in the field of silicon-based biomedical sensing technologies.

We compared levels of Aβ by self-standard in plasma using an interdigitated microelectrode sensor to detect Alzheimer disease.

Monitoring and assessing the progression of symptoms in neurodegenerative diseases, including Alzheimer’s and Parkinson’s disease, are critical for improving patient outcomes. Traditional biomarkers, such as cerebrospinal fluid analysis and brain imaging, are widely used to investigate the underlying mechanisms of disease and enable early diagnosis. In contrast, digital biomarkers derived from phenotypic changes—such as EEG, eye movement, gait, and speech analysis—offer a noninvasive and accessible alternative. Leveraging portable and widely available devices, such as smartphones and wearable sensors, digital biomarkers are emerging as a promising tool for ND diagnosis and monitoring. This review highlights the comprehensive developments in digital biomarkers, emphasizing their unique advantages and integration potential alongside traditional biomarkers.

Faradaic electrochemical impedance spectroscopy (f-EIS) in the presence of redox reagent, e.g., [Fe(CN)₆]^3−/4−, is widely used in biosensors owing to its high sensitivity. However, in sensors detecting amyloid beta (Aβ), the redox reagent can cause the aggregation of Aβ, which is a disturbance factor in accurate detection. Here, we propose an interdigitated microelectrode (IME) based f-EIS technique that can alleviate the aggregation of Aβ and achieve high sensitivity by buffer control. The proposed method was verified by analyzing three different EIS-based sensors: non-faradaic EIS (nf-EIS), f-EIS, and the proposed f-EIS with buffer control. We analyzed the equivalent circuits of nf-EIS and f-EIS sensors. The dominant factors of sensitivity were analyzed, and the impedance change rates via Aβ reaction was compared. We measured the sensitivity of the IME sensors based on nf-EIS, f-EIS, and the proposed f-EIS. The results demonstrate that the proposed EIS-based IME sensor can detect Aβ with a sensitivity of 7.40-fold and 10.93-fold higher than the nf-EIS and the f-EIS sensors, respectively.

This review critically analyzes various 2D materials—either synthesized or exfoliated from bulk 3D counterparts—for electrochemical and electrical biosensing applications. Each material exhibits unique electrochemical properties and benefits from its inherent 2D features, enabling abundant active sites for biomolecule interaction. Key challenges include synthesizing or exfoliating these materials and processing them for the cost‐effective and scalable production of biosensors. Additionally, the functionalization of 2D materials is crucial for effective bioreceptor immobilization, which directly affects selectivity, sensitivity, and overall performance. Certain 2D materials are better suited for specific sensing applications. For instance, 2D metal–organic frameworks or covalent organic frameworks show potential in electrochemical sensing due to their porous structures and high density of active sites. Transition metal dichalcogenides, such as MoS ₂ and WS ₂ , show promise for field‐effect transistor‐based biosensors. Reduced graphene oxide and MXenes, with tunable surface functionalities, show promise for both electrical and electrochemical sensing platforms. Monoelemental 2D materials (Xenes) hold dual‐sensing potential, though synthesis and stability remain challenges for some. Hydrogenated Xenes offer improved stability, semiconducting behavior, and functionalization potential, making them strong candidates for biosensing. This review highlights these challenges and advantages while providing perspectives and future directions for optimizing 2D materials in biosensor development.