Unlocking early detection of Alzheimer's disease: The emerging role of nanomaterial-based optical sensors

Challenges and Opportunities: Nanomaterials in Epilepsy Diagnosis

Epilepsy is a common neurological disorder characterized by a significant rate of disability. Accurate early diagnosis and precise localization of the epileptogenic zone are essential for timely intervention, seizure prevention, and personalized treatment. However, over 30% of patients with epilepsy exhibit negative results on electroencephalography and magnetic resonance imaging (MRI), which can lead to misdiagnosis and subsequent delays in treatment. Consequently, enhancing diagnostic methodologies is imperative for effective epilepsy management. The integration of nanomaterials with biomedicine has led to the development of diagnostic tools for epilepsy. Key advancements include nanomaterial-enhanced neural electrodes, contrast agents, and biochemical sensors. Nanomaterials improve the quality of electrophysiological signals and broaden the detection range of electrodes. In imaging, functionalized magnetic nanoparticles enhance MRI sensitivity, facilitating localization of the epileptogenic zone. NIR-II nanoprobes enable tracking of seizure-related biomarkers with deep tissue penetration. Furthermore, nanomaterials enhance the sensitivity of biochemical sensors for detecting epilepsy biomarkers, which is crucial for early detection. These advancements significantly increase diagnostic sensitivity and specificity. However, challenges remain, particularly regarding biosafety, quality control, and the scalability of fabrication processes. Overcoming these obstacles is essential for successful clinical translation. Artificial-intelligence-based big data analytics can facilitate the development of diagnostic tools by screening nanomaterials with specific properties. This approach may help to address current limitations and improve both effectiveness and safety. This review explores the application of nanomaterials in the diagnosis and detection of epilepsy, with the objective of inspiring innovative ideas and strategies to enhance diagnostic effectiveness.

Fluorescent aptasensor based on target-induced hairpin conformation switch coupled with nicking enzyme-assisted signal amplification for detection of beta-amyloid oligomers in cerebrospinal fluid

A fluorescent aptasensor was developed based on target-induced hairpin conformation switch coupled with nicking enzyme-assisted signal amplification (NESA) to detect the oligomeric form of ß-amyolid peptide (AβO) in cerebrospinal fluid. The hairpin DNA probe (HP) was specifically designed to recognize AβO. When AβO is present in the sensing system, it induces an HP conformational switch and triggers the NESA reaction. After evaluating the parameters of the aptasensor system, we selected Hairpin10, which has a 10-nucleotide extended sequence, as the hairpin sequence that interacts with AβO. The quantitative linear range of the proposed aptasensor is from 11.3 to 113 ng mL-1 in artificial cerebrospinal fluid (aCSF), and the detection limit was 7.29 ng mL-1. The present work realized the assay of AβO in aCSF with satisfactory quantitative results.

Digoxin detection for therapeutic drug monitoring using target-triggered aptamer hairpin switch and nicking enzyme-assisted signal amplification

Digoxin, a cardiac glycoside drug, is commonly used to treat heart failure and arrhythmias. The therapeutic concentration range of digoxin, with a narrow therapeutic index, is between 0.5 and 2.0 ng mL-1. Hence, it is important for patients to monitor their blood levels after taking medication to achieve effective treatment and reduce the likelihood of experiencing drug side effects. Due to the complex steps and high cost of immunoassays, aptasensors that use aptamers to recognize the targets offer the advantages of low cost and good stability over other analysis methods. Nicking enzyme-assisted signal amplification is a novel isothermal signal amplification technology that relies on nicking enzymes to recognize and cleave restriction sites on one oligonucleotide strand. In this study, we develop a fluorescent aptasensor coupled with target-triggered aptamer hairpin switch and nicking enzyme-assisted signal amplification for digoxin detection in plasma for therapeutic drug monitoring. After optimizing the experimental parameters, we design hairpin probes with ten base pairs of the aptamer sequence and extended sequence complement to react with digoxin in a 10 mM Tris buffer containing 150 mM NaCl and 50 mM MgCl2 (pH 7.4). The signal amplification reactions were performed for 3 hours. The fluorescent aptasensor exhibited high sensitivity with a detection limit of 88 pg mL-1 for detecting digoxin in plasma and a linear range from 0.1 ng mL-1 to 5 ng mL-1. This technology was successfully used for digoxin detection to improve treatment effectiveness and minimize the risk of adverse side effects.