First-Principles Approach for Assessing the Detection of Alzheimer’s Biomarkers Using Titanium Carbide MXenes

Narender Kumar, Hyeonhu Bae, Hoonkyung Lee, Tanveer Hussain, Abu Anand, Chandra Veer Singh, Nacir Tit

Research output: Contribution to journalArticlepeer-review

Abstract

Alzheimer’s disease (AD) is considered the most common neurodegenerative condition and is the main cause of dementia. AD progresses rapidly and is the major cause of death in the elderly population; thus, an early diagnosis is of vital importance. Medical research has successfully characterized a set of volatile organic compounds (VOCs) present in exhaled patient’s breath to be considered as fingerprints of AD. The present work, for the first time, aims at computationally designing highly efficient nano-biosensors capable of detecting the VOC biomarkers. We apply density functional theory (DFT) to study the adsorption properties of three representative VOCs, namely, 2,3-dimethylheptane (23-DMH), butylated hydroxytoluene (BHT), and pivalic acid (PVA), versus four interfering air molecules (i.e., N2, O2, CO2, and H2O) on four different MXenes (i.e., thick Ti3C2Tx and thin Ti2CTx MXenes, Tx = O or S). All the molecules are found to exhibit physisorption interactions on the studied MXenes. Nevertheless, the energetic analysis shows clear selective adsorption of BHT on Ti3C2O2 with an adsorption energy of −1.513 eV, which is desirable for practical sensing applications. Furthermore, distinct from all other VOCs and interfering air molecules, BHT oxidizes to the O passivation layer of MXenes with a charge transfer of +0.421e and induces magnetization of 0.467 μB to transform the surface to become ferromagnetic. These changes are very promising to rectify the current-voltage characteristics and yield a high sensor response. We further performed thermodynamic analysis through the Langmuir adsorption model, which ensures the excellent adsorption performance of Ti3C2O2 over a broad range of BHT concentrations at ambient temperature. Therefore, Ti3C2O2 could be considered as highly sensitive and selective nano-biosensors toward the fingerprint VOCs of AD.

Original languageEnglish
Pages (from-to)6873-6884
Number of pages12
JournalACS Applied Nano Materials
Volume7
Issue number7
DOIs
Publication statusPublished - Apr 12 2024

Keywords

  • DFT
  • MXenes−molecule interaction
  • chemisorption and physisorption
  • early diagnosis of Alzheimer's disease
  • solid-state chemistry
  • van der Waals interaction

ASJC Scopus subject areas

  • General Materials Science

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