Aptamer–field-effect transistors overcome Debye length limitations for small-molecule sensing

Science, Journal Year: 2018, Volume and Issue: 362(6412), P. 319 - 324

Published: Sept. 6, 2018

Transistor sensing in salt solutions Molecular binding to receptors on the surface of field-effect transistors (FETs) can be sensed through changes transconductance. However, saline typically used with biomolecules create an electrical double layer that masks any events occur within about 1 nanometer from surface. Nakatsuka et al. overcame this limitation by using large, negatively charged DNA stem loop structures that, upon ligand binding, cause conformational FET, even high ionic strength. The authors demonstrate molecules such as dopamine artificial cerebrospinal fluid well neutral glucose and zwitterion like sphingosine-1-phosphate. Science , issue p. 319

Language: Английский

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Fundamentals of fast-scan cyclic voltammetry for dopamine detection

The Analyst, Journal Year: 2019, Volume and Issue: 145(4), P. 1158 - 1168

Published: Dec. 26, 2019

Fast-scan cyclic voltammetry (FSCV) is used with carbon-fiber microelectrodes for the real-time detection of neurotransmitters on subsecond time scale. With FSCV, potential ramped up from a holding to switching and back, usually at 400 V s-1 scan rate frequency 10 Hz. The plot current vs. applied potential, voltammogram (CV), has very different shape FSCV than traditional collected rates which are 1000-fold slower. Here, we explore theory focus dopamine detection. First, examine CVs. Background currents, 100-fold higher faradaic subtracted out. Peak separation primarily due slow electron transfer kinetics, while symmetrical peak exhaustive electrolysis all adsorbed neurotransmitters. Second, explain origins waveform, factors that limit (oxygen reduction), (water oxidation), (electrode instability), repetition (adsorption). Third, discuss data analysis, visualization color plots, automated algorithms like principal components regression distinguish pH changes. Finally, newer applications discussed, including optimization waveforms analyte selectivity, carbon nanomaterial electrodes trap dopamine, basal level measurements facilitate neurotransmitter longer complex, but understanding it enables better development new techniques monitor in vivo.

Language: Английский

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Practical Aspects of Cyclic Voltammetry: How to Estimate Reduction Potentials When Irreversibility Prevails

Journal of The Electrochemical Society, Journal Year: 2019, Volume and Issue: 166(5), P. H3175 - H3187

Published: Jan. 1, 2019

What is the best approach for estimating standard electrochemical potentials, E(0), from voltammograms that exhibit chemical irreversibility? The lifetimes of oxidized or reduced forms majority known redox species are considerably shorter than voltammetry acquisition times, resulting in irreversibility and making answer to this question outmost importance. Half-wave E(1/2), provide experimentally obtainable representation E(0). Due irreversible oxidation reduction, however, lack cathodic anodic peaks cyclic renders E(1/2) unattainable. Therefore, we evaluate how closely alternative readily voltammograms, estimate Our analysis reveals that, when not available, inflection-point potentials characterization couples. While peak most extensively used descriptor systems, they deviate significantly especially at high scan rates. Even partially as pronounced one, half-wave still estimates importance these findings extends beyond realm electrochemistry impacts fields, such materials engineering, photonics, cell biology, solar energy engineering neuroscience, where a key tool.

Language: Английский

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Next-generation interfaces for studying neural function

Nature Biotechnology, Journal Year: 2019, Volume and Issue: 37(9), P. 1013 - 1023

Published: Aug. 12, 2019

Language: Английский

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Recent advances in fast-scan cyclic voltammetry

The Analyst, Journal Year: 2019, Volume and Issue: 145(4), P. 1087 - 1102

Published: Dec. 27, 2019

We reviewed recent advances and future challenges in fast-scan cyclic voltammetry for real-time detection of neurotransmitters.

Language: Английский

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A dopaminergic switch for fear to safety transitions

Nature Communications, Journal Year: 2018, Volume and Issue: 9(1)

Published: June 21, 2018

Overcoming aversive emotional memories requires neural systems that detect when fear responses are no longer appropriate so they can be extinguished. The midbrain ventral tegmental area (VTA) dopamine system has been implicated in reward and more broadly signaling a better-than-expected outcome occurred. This suggests it may important guiding to safety transitions. We report an expected does not occur, activity neurons is necessary extinguish behavioral engage molecular events extinction learning circuits. Furthermore, specific projection the nucleus accumbens medial shell partially responsible for this effect. In contrast, separate prefrontal cortex opposes learning. demonstrates novel function canonical VTA-dopamine reveals opposing roles different neuron projections

Language: Английский

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Imaging Neurotransmitter and Neuromodulator Dynamics In Vivo with Genetically Encoded Indicators

Neuron, Journal Year: 2020, Volume and Issue: 108(1), P. 17 - 32

Published: Oct. 1, 2020

Language: Английский

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Implantable aptamer–field-effect transistor neuroprobes for in vivo neurotransmitter monitoring

Science Advances, Journal Year: 2021, Volume and Issue: 7(48)

Published: Nov. 24, 2021

Implantable aptamer transistor probes for in vivo neurotransmitter monitoring advance brain activity recording.

Language: Английский

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Real-Time, In Vivo Molecular Monitoring Using Electrochemical Aptamer Based Sensors: Opportunities and Challenges

ACS Sensors, Journal Year: 2022, Volume and Issue: 7(10), P. 2823 - 2832

Published: Oct. 7, 2022

The continuous, real-time measurement of specific molecules in situ the body would greatly improve our ability to understand, diagnose, and treat disease. vast majority continuous molecular sensing technologies, however, either (1) rely on chemical or enzymatic reactivity their targets, sharply limiting scope, (2) have never been shown (and likely will be shown) operate complex environments found vivo. Against this background, here we review electrochemical aptamer-based (EAB) sensors, an approach monitoring that has now seen 15 years academic development. strengths EAB platform are significant: date it is only technology functions independently its thus general, supports vivo measurements. Specifically, using sensors we, others, already reported real-time, seconds-resolved measurements multiple, unrelated drugs metabolites veins tissues live animals. these strengths, detail platform's remaining weaknesses, which include still limited duration (hours, rather than more desirable days) difficulty obtaining sufficiently high performance aptamers against new before then detailing promising approaches overcoming hurdles. Finally, close by exploring opportunities believe potentially revolutionary (as well as a few, possibly competing, technologies) create for both researchers clinicians.

Language: Английский

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Absolute measurement of fast and slow neuronal signals with fluorescence lifetime photometry at high temporal resolution

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 12, 2025

The concentrations of extracellular and intracellular signaling molecules, such as dopamine cAMP, change over both fast slow timescales impact downstream pathways in a cell-type specific manner. Fluorescence sensors currently used to monitor signals vivo are typically optimized detect fast, relative changes concentration the target molecule. They less well suited slowly-changing rarely provide absolute measurements either components. Here, we developed system for fluorescence lifetime photometry at high temporal resolution (FLIPR) that utilizes frequency-domain analog processing measure genetically-encoded speed but with long-term stability picosecond precision freely moving mice. We applied FLIPR investigate two functionally distinct regions striatum, nucleus accumbens core (NAC) tail striatum (TOS). observed higher tonic levels baseline TOS compared NAC detected differential dynamic responses phasic appetitive aversive stimuli. Thus, enables simple monitoring time-scale neuronal units, revealing previously unappreciated spatial variation even well-studied systems.

Language: Английский

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