scholarly journals Quantum capacitance-limited MoS2 biosensors enable remote label-free enzyme measurements

Nanoscale ◽  
2019 ◽  
Vol 11 (33) ◽  
pp. 15622-15632 ◽  
Author(s):  
Son T. Le ◽  
Nicholas B. Guros ◽  
Robert C. Bruce ◽  
Antonio Cardone ◽  
Niranjana D. Amin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Free Enzyme ◽  
Quantum Capacitance ◽  
Label Free

Atomically thin, quantum capacitance limited, field-effect transistors, enable measurements of biological enzymes implicated in Alzheimer's disease with unprecedented resolution.

scholarly journals Rapid, quantitative therapeutic screening for Alzheimer's enzymes enabled by optimal signal transduction with transistors

The Analyst ◽  
2020 ◽  
Vol 145 (8) ◽  
pp. 2925-2936
Author(s):  
Son T. Le ◽  
Michelle A. Morris ◽  
Antonio Cardone ◽  
Nicholas B. Guros ◽  
Jeffery B. Klauda ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Signal Transduction ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Therapeutic Molecules ◽  
Optimal Signal

Commercially sourced silicon field-effect transistors enable sensitive measurements of small therapeutic molecules that regulate enzymes implicated in Alzheimer's disease.

scholarly journals Biologically sensitive field-effect transistors: from ISFETs to NanoFETs

2016 ◽  
Vol 60 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Vivek Pachauri ◽  
Sven Ingebrandt
Keyword(s):  
Field Effect ◽  
Gate Dielectric ◽  
Gate Dielectrics ◽  
Field Effect Transistors ◽  
Silicon Nanowire ◽  
Label Free ◽  
Biomolecular Detection ◽  
New Device ◽  
Label Free Detection ◽  
History Of

Biologically sensitive field-effect transistors (BioFETs) are one of the most abundant classes of electronic sensors for biomolecular detection. Most of the time these sensors are realized as classical ion-sensitive field-effect transistors (ISFETs) having non-metallized gate dielectrics facing an electrolyte solution. In ISFETs, a semiconductor material is used as the active transducer element covered by a gate dielectric layer which is electronically sensitive to the (bio-)chemical changes that occur on its surface. This review will provide a brief overview of the history of ISFET biosensors with general operation concepts and sensing mechanisms. We also discuss silicon nanowire-based ISFETs (SiNW FETs) as the modern nanoscale version of classical ISFETs, as well as strategies to functionalize them with biologically sensitive layers. We include in our discussion other ISFET types based on nanomaterials such as carbon nanotubes, metal oxides and so on. The latest examples of highly sensitive label-free detection of deoxyribonucleic acid (DNA) molecules using SiNW FETs and single-cell recordings for drug screening and other applications of ISFETs will be highlighted. Finally, we suggest new device platforms and newly developed, miniaturized read-out tools with multichannel potentiometric and impedimetric measurement capabilities for future biomedical applications.

scholarly journals Label-free vibrational imaging of different Aβ plaque types in Alzheimer’s disease reveals sequential events in plaque development

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Dominik Röhr ◽  
Baayla D. C. Boon ◽  
Martin Schuler ◽  
Kristin Kremer ◽  
Jeroen J. M. Hoozemans ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Tissue ◽  
Raman Imaging ◽  
Label Free ◽  
Human Brain Tissue ◽  
Plaque Development ◽  
Β Sheets ◽  
Diffuse Plaques ◽  
Insight Into

AbstractThe neuropathology of Alzheimer’s disease (AD) is characterized by hyperphosphorylated tau neurofibrillary tangles (NFTs) and amyloid-beta (Aβ) plaques. Aβ plaques are hypothesized to follow a development sequence starting with diffuse plaques, which evolve into more compact plaques and finally mature into the classic cored plaque type. A better molecular understanding of Aβ pathology is crucial, as the role of Aβ plaques in AD pathogenesis is under debate. Here, we studied the deposition and fibrillation of Aβ in different plaque types with label-free infrared and Raman imaging. Fourier-transform infrared (FTIR) and Raman imaging was performed on native snap-frozen brain tissue sections from AD cases and non-demented control cases. Subsequently, the scanned tissue was stained against Aβ and annotated for the different plaque types by an AD neuropathology expert. In total, 160 plaques (68 diffuse, 32 compact, and 60 classic cored plaques) were imaged with FTIR and the results of selected plaques were verified with Raman imaging. In diffuse plaques, we detect evidence of short antiparallel β-sheets, suggesting the presence of Aβ oligomers. Aβ fibrillation significantly increases alongside the proposed plaque development sequence. In classic cored plaques, we spatially resolve cores containing predominantly large parallel β-sheets, indicating Aβ fibrils. Combining label-free vibrational imaging and immunohistochemistry on brain tissue samples of AD and non-demented cases provides novel insight into the spatial distribution of the Aβ conformations in different plaque types. This way, we reconstruct the development process of Aβ plaques in human brain tissue, provide insight into Aβ fibrillation in the brain, and support the plaque development hypothesis.

scholarly journals Network Analysis of a Membrane-Enriched Brain Proteome across Stages of Alzheimer’s Disease

Proteomes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 30 ◽  
Author(s):  
Lenora Higginbotham ◽  
Eric Dammer ◽  
Duc Duong ◽  
Erica Modeste ◽  
Thomas Montine ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Network Analysis ◽  
Proteomic Analysis ◽  
Expression Patterns ◽  
Label Free ◽  
Post Mortem Brain ◽  
Brain Proteome ◽  
Associated Proteins ◽  
Membrane Bound

Previous systems-based proteomic approaches have characterized alterations in protein co-expression networks of unfractionated asymptomatic (AsymAD) and symptomatic Alzheimer’s disease (AD) brains. However, it remains unclear how sample fractionation and sub-proteomic analysis influences the organization of these protein networks and their relationship to clinicopathological traits of disease. In this proof-of-concept study, we performed a systems-based sub-proteomic analysis of membrane-enriched post-mortem brain samples from pathology-free control, AsymAD, and AD brains (n = 6 per group). Label-free mass spectrometry based on peptide ion intensity was used to quantify the 18 membrane-enriched fractions. Differential expression and weighted protein co-expression network analysis (WPCNA) were then used to identify and characterize modules of co-expressed proteins most significantly altered between the groups. We identified a total of 27 modules of co-expressed membrane-associated proteins. In contrast to the unfractionated proteome, these networks did not map strongly to cell-type specific markers. Instead, these modules were principally organized by their associations with a wide variety of membrane-bound compartments and organelles. Of these, the mitochondrion was associated with the greatest number of modules, followed by modules linked to the cell surface compartment. In addition, we resolved networks with strong associations to the endoplasmic reticulum, Golgi apparatus, and other membrane-bound organelles. A total of 14 of the 27 modules demonstrated significant correlations with clinical and pathological AD phenotypes. These results revealed that the proteins within individual compartments feature a heterogeneous array of AD-associated expression patterns, particularly during the preclinical stages of disease. In conclusion, this systems-based analysis of the membrane-associated AsymAD brain proteome yielded a unique network organization highly linked to cellular compartmentalization. Further study of this membrane-associated proteome may reveal novel insight into the complex pathways governing the earliest stages of disease.

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