Verification of gas sensors to detect Alzheimer’s disease biomarkers with diabetic rats

Abstract

Background Evidences prove that individuals with Type‐2 insulin resistant diabetes have a two‐three folder greater risk for Alzheimer’s disease (AD). The abnormal glucose metabolism leads to the increased production of reactive oxygen species (ROS) a hallmark of diabetes and AD. ROS‐induced lipid peroxidation can lead to neuronal damage and cell death and is thought to be a contributing factor to disease progression in AD. Method Recently, we introduced an array of electrochemical gas sensor to detect volatile organic compounds (VOCs) biomarkers in the exhaled breath. The sensors were later tested with a rat model that combined the human ApoE4 gene with aging and the Western diet. Gas sensors fabricated from molecularly imprinted polymer‐graphene were engineered to react with alkanes and small fatty acids (butylated hydroxytoluene, pivalic acid and, 2,3 dimethyl heptane) associated with lipid peroxidation. With a detection sensitivity in parts per trillion, the sensors were sensitive against the breath of wild‐type and APOE4 male rats with 100% sensitivity, specificity and, accuracy. The results were matching with the resting state BOLD functional connectivity which is used to assess hippocampal function. Result The present study was designed to test the Alzheimer’s sensor on diabetic rats. Since diabetes and AD share the same vascular problem, the question was that whether they share the same biomarkers as well or not. So, six rats with diabetic symptoms were tested with AD sensors and the result was negative. None of the sensors was sensitive to the breath of diabetic rats. Conclusion This result is confirming that the sensors are detecting biomarkers that are only specific to Alzheimer's disease, not to a very similar disease such as diabetes.

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

“…We aim to study the adsorptions of three VOCs related to Alzheimer’s biomarkers, namely, (i) 2,3-dimethylheptane (23-DMH), (ii) butylated hydroxytoluene (BHT), and (iii) pivalic acid (PVA), on Ti 3 C 2 T x and Ti 2 C 2 T x MXenes (with T x = O and S). , Figure shows the top and side views of four MXenes: (a) Ti 3 C 2 O 2 , (b) Ti 3 C 2 S 2 , (c) Ti 2 CO 2 , and (d) Ti 2 CS 2 , after atomic relaxations. In passivation, we consider the oxygen and sulfur functionalization because these elements have high electronegativity characters and should enhance the dipole moments within the top layers of these MXenes .…”

“…Atomic Relaxations. We aim to study the adsorptions of three VOCs related to Alzheimer's biomarkers, namely, (i) 2,3-dimethylheptane (23-DMH), 53 (ii) butylated hydroxytoluene (BHT), 53 and (iii) pivalic acid (PVA), 53 on Ti 3 C 2 T x and Ti 2 C 2 T x MXenes (with T x = O and S). 54,55 Figure 1 shows the top and side views of four MXenes: (a) Ti 3 C 2 O 2 , (b) Ti 3 C 2 S 2 , (c) Ti 2 CO 2 , and (d) Ti 2 CS 2 , after atomic relaxations.…”

“…4−6 Emam and co-workers reported that amyloid beta (Aβ) plaques and neurofibrillary tangles were the pathological hallmarks of late-stage AD. 4 They thereafter proposed three representative VOCs for the early diagnosis of AD, which are (i) 2,3-dimethylheptane (23-DMH), (ii) butylated hydroxytoluene (BHT), and (iii) pivalic acid (PVA).…”

Detection of PPB-Level H2S Concentrations in Exhaled Breath Using Au Nanosheet Sensors with Small Variability, High Selectivity, and Long-Term Stability

“…H ealth checkups based on breath testing are attracting attention. 1,2 Exhaled breath contains more than 200 types of chemical species, and the kinds and amounts of these species give information about various diseases. 3−5 Hence, the continuous evaluation of the gas components of exhaled breath enables the detection of diseases, even in presymptomatic states.…”

“…Health checkups based on breath testing are attracting attention. , Exhaled breath contains more than 200 types of chemical species, and the kinds and amounts of these species give information about various diseases. − Hence, the continuous evaluation of the gas components of exhaled breath enables the detection of diseases, even in presymptomatic states . Exhaled breath contains hydrogen sulfide (H 2 S) molecules produced by sulfate-reducing bacteria at concentrations of less than 1000 parts per billion (ppb). , H 2 S is closely related to various health issues, such as halitosis, gum disease, and gastrointestinal problems. , Exhaled breath contains abundant reducing gases other than H 2 S, with the concentration of H 2 S being much lower than those of these other reducing gases (e.g., 1–100 ppm for hydrogen (H 2 )). , Thus, breath monitoring requires the development of H 2 S sensors with fast responses, parts per billion-level limits of detection (LODs), and high selectivity against interfering gases in exhaled breath.…”