In order to have an enhanced applicability, Fe2O3 nanoparticles were altered with films of poly (neutral red) generated by electropolymerization in the presence of ethaline deep eutectic solvents (DES) with the addition of acid dopants. achieved in the detection of AD biomarkers, the strategies followed for the incorporation of nanomaterials and its effect in biosensors performance. strong class=”kwd-title” Keywords: Alzheimers disease, neurodegenerative diseases, nanoparticles, labels, electroactivity, electrocatalysis, electrochemistry, immunosensors, biosensors, nanomaterials 1. Introduction Alzheimers disease (AD) is usually a debilitating neurodegenerative disorder and the current main cause of dementia [1]. This untreatable disease affected more than 50 million people in Rabbit Polyclonal to ATG4D 2019 and this number is estimated to increase to 152 million by 2050 according to Alzheimers disease international (ADI) and the World health business (WHO) [2]. INH14 Even though AD affects mainly older people, it is considered a multifactorial disease that appears before 65 years in 4% of cases. Commonly, AD starts with an initial phase, known as moderate cognitive impairment (MCI), characterized by unclear episodes of memory and non-memory related impairments, that evolves to symptoms of dementia, implying deterioration of cognitive functions, memory loss, inability to perform daily tasks or time and space disorientation [3,4]. Cognitive decline associated with AD has a significant impact not only in patients, but also in families and careers, affecting them both emotionally and economically. In 2015, the Global Economic Impact of AD was of 818 billion US dollars, nearly 1.1% of the Gross Domestic Product (GDP) and it is expected to grow to two trillion US dollars by 2030 [5]. Due to its socio-economic effect, the Group of eight (G8) inter-governmental political forum stated in 2013 that discovering a therapy before 2025 was a global priority [1]. Unfortunately, there is still no treatment for AD, although recent research has been focused on disease-modifying drugs for early stages of the disease owing to its increased efficiency [1,6], what highlights the importance of an early detection. The diagnose of AD can be performed by conducting cognitive assessments and by imaging techniques, mainly magnetic resonance imaging (MRI), positron emission tomography (PET) and near infrared (NIR), used to detect abnormalities in patient brains [7]. The analysis of cerebrospinal fluid (CSF) and blood plasma biomarkers by immunohistochemistry and enzyme linked immunosorbent assay (ELISA) have also been used [8]. These techniques are time-consuming, expensive and invasive and do not constitute a generalize method for an early detection of AD. Due INH14 to that, there is a still a need to develop easy-to-use, low-cost, sensitive methods INH14 to facilitate the detection of AD and that require less amount of sample to minimize the extraction procedures performed on patients, as it is the case of electrochemical biosensors. In this review, electrochemical biosensors for the detection of AD are revised, according to the biomarkers detected and focusing on the use of nanomaterials in these analytical devices to improve biosensors performance. 2. Biomarkers for Alzheimers Disease AD is usually a multifactorial disease that evolves progressively until the first symptoms of dementia appear with variable clinical among patients. This fluidity troubles detection only by cognitive assessments, favoring misdiagnosis and delaying medication administration [8]. Due to that, biomarkers have gained importance for an early diagnosis of AD. Even though molecular bases of AD are not well established, amyloid beta (A) peptides plaques and intracellular neurofibrillary tangles (NFTs) of hyperphosphorylated microtubule-associated protein tau (MAPT) are the most accepted pathological hallmarks of the disease. A plaques are composed by aggregated A peptides, generated by the proteolysis of amyloid precursor protein (APP), a transmembrane type I glycoprotein that is present in almost all tissues and whose physiological function is still unknown [9]. The cleavage of APP occurs by two different pathways: amyloidogenic, which is the causative of amyloidogenic diseases, including AD, and non-amyloidogenic [10]. In the amyloidogenic pathway, APP is usually cleaved by -secretase (identified as BACE1) and -secretase (composed of four proteins including presenilin protein) around the.