Arjum, Ajith MohanDeshpande, SudhaunshDunlop, TomNorman, BethOliviera, DanielaVulpe, GeorgetaMoreira, FelisminaSharma, Sanjiv2025-02-072025-02-072024Ajith Mohan Arjun, Sudhaunsh Deshpande, Tom Dunlop, Beth Norman, Daniela Oliviera, Georgeta Vulpe, Felismina Moreira, Sanjiv Sharma, Alzheimer's diagnosis beyond cerebrospinal fluid: Probe-Free Detection of Tau Proteins using MXene based redox systems and molecularly imprinted polymers, Biosensors and Bioelectronics: X, Volume 20, 2024, 100513, ISSN 2590-1370, https://doi.org/10.1016/j.biosx.2024.100513.2590-1370http://hdl.handle.net/10400.22/29432Phosphorylated Tau proteins are promising biomarkers for the diagnosis and prognosis of Alzheimer's disease. This study presents a novel voltametric sensor using a vanadium MXene polydopamine (VxPDA) redox active composite and a Tau-441-specific polyaniline molecularly imprinted polymer (PANI MIP) for the sensitive detection of Tau-441 in interstitial fluid (ISF) and plasma. The VxPDA/PANI MIP sensor demonstrates a broad detection range of 5 fg/mL to 5 ng/mL (122 aM/L to 122 pM/L) in ISF without the use of redox mediators, with a lower limit of detection (LOD) of 2.3 fg/mL (60 aM/L). Furthermore, a handheld device utilizing this technology successfully detects Tau-441 in artificial serum with high sensitivity (5 fg/mL to 150 fg/mL (122 aM/L to 366 aM/L)) and specificity within a clinically relevant range. The rapid detection time (∼32 min) and low cost (∼£20/device) of this sensor highlight its potential for minimally invasive, early AD diagnosis in clinical settings. This advancement aims to facilitate a transition away from invasive cerebrospinal fluid (CSF)-based diagnostic techniques for AD.engjournal article10.1016/j.biosx.2024.100513