Aptamer-functionalized neural recording electrodes for the direct measurement of cocaine in vivo

Correction for ‘Aptamer-functionalized neural recording electrodes for the direct measurement of cocaine in vivo’ by I. Mitch Taylor et al., J. Mater. Chem. B, 2017, 5, 2445–2458.

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Sea of Electrodes Array (SEA): Extremely Dense and High-Count Silicon-Based Electrode Array Technology for High-Resolution High-Bandwidth Interfacing with 3D Neural Structures

10.1101/2021.01.24.427975 ◽

2021 ◽

Author(s):

Amin Sandoughsaz Zardini ◽

Behnoush Rostami ◽

Khalil Najafi ◽

Vaughn L. Hetrick ◽

Omar J. Ahmed

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Electrode Array ◽

High Count ◽

Array Technology ◽

High Bandwidth ◽

Length Width ◽

Silicon Based ◽

The Brain

AbstractIn this work, we propose a new silicon-based micro-fabrication technology to fabricate 3D high-density high-electrode-count neural micro-probe arrays scalable to thousands and even millions of individual electrodes with user-defined length, width, shape, and tip profile. This unique technology utilizes DRIE of ultra-high aspect-ratio holes in silicon and refilling them with multiple films to form thousands of individual needles with metal tips making up the “sea-of-electrodes” array (SEA). World-record density of 400 electrodes/mm2 in a 5184-needle array is achieved. The needles are ~0.5-1.2mm long, <20μm wide at the base, and <1μm at the tip. The silicon-based structure of these 3D array probes with sharp tips, makes them stiff enough and easily implantable in the brain to reach a targeted region without failing. Moreover, the high aspect ratio of these extremely fine needles reduces the tissue damage and improves the chronic stability. Functionality of the electrodes is investigated using acute in vivo recording in a rat barrel field cortex under isoflurane anesthesia.

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Electrochemical detection of exogenously administered melatonin in the brain

The Analyst ◽

10.1039/d0an00051e ◽

2020 ◽

Vol 145 (7) ◽

pp. 2612-2620 ◽

Cited By ~ 2

Author(s):

Elisa Castagnola ◽

Kevin Woeppel ◽

Asiyeh Golabchi ◽

Moriah McGuier ◽

Neharika Chodapaneedi ◽

...

Keyword(s):

Electrochemical Detection ◽

Square Wave Voltammetry ◽

Electrochemical Measurement ◽

Square Wave ◽

Wave Voltammetry ◽

The Brain

Optimized square wave voltammetry for electrochemical measurement of exogenously administered MT in vivo.

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Fabrication and Characterization of Biodegradable Metal Based Microelectrodes for In Vivo Neural Recording

MRS Advances ◽

10.1557/adv.2019.302 ◽

2019 ◽

Vol 4 (46-47) ◽

pp. 2471-2477

Author(s):

Chaoxing Zhang ◽

Teresa H. Wen ◽

Khaleel A. Razak ◽

Jiajia Lin ◽

Edgar Villafana ◽

...

Keyword(s):

Neural Recording ◽

Neural Signals ◽

Secondary Surgery ◽

New Class ◽

Fabrication And Characterization ◽

Evoked Activity ◽

First Time ◽

The Brain

ABSTRACT:Neural electrodes have been widely used to monitor neural signals and/or deliver electrical stimulation in the brain. Currently, biodegradable and biocompatible materials have been actively investigated to create temporary electrodes that could degrade after serving their functions for neural recording and stimulation from days to months. The new class of biodegradable electrodes eliminate the necessity of secondary surgery for electrode removal. In this study, we created biodegradable, biocompatible, and implantable magnesium (Mg)-based microelectrodes for in vivo neural recording for the first time. Specifically, conductive poly-3,4-ethylenedioxythiophene (PEDOT) was first deposited onto Mg microwire substrates by electrochemical deposition, and a biodegradable insulating polymer was subsequently sprayed onto the surface of electrodes. The tip of electrodes was designed to be conductive for neural recording and stimulation, while the rest of electrodes was insulated with a polymer that is biocompatible with neural tissue. The impedance of Mg-based microelectrodes and their performance during neural recording in the auditory cortex of a mouse were studied. The results first demonstrated the capability of Mg-based microelectrodes for in vivo recording of multi-unit stimulus-evoked activity in the brain.

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A Wirelessly Powered Implantable CMOS Neural Recording Sensor Array using Pulse-based Neural Amplifier

10.1101/809509 ◽

2019 ◽

Author(s):

Geoffrey Mulberry ◽

Kevin A. White ◽

Brian N. Kim

Keyword(s):

Power Transmission ◽

Neural Recording ◽

In Vivo Studies ◽

Wireless Power ◽

Wireless Data ◽

Electrical Measurements ◽

Wireless Data Transmission ◽

Delta Modulation ◽

The Brain

AbstractThe most important organ in the human body is unquestionably the brain. Yet, despite its importance, it is one of the least well understood organs. One reason for this lack of understanding of the brain is the lack of data available to researchers from in vivo studies. Historically, collecting measurements from the brain has been difficult due to the high risk to the patient. Recently technology has been developed to allow electrical measurements to be taken from the brain directly, however most systems involve non-permanent sensors because of the requirement for transcranial wiring for power and data. Developments in the field of CMOS circuit design, wireless power transmission, and wireless data transmission have enabled the creation of implantable neural recording devices as a combination of these technologies. The implant designed in this paper is ∼15 mm in diameter and 2 mm at its thickest point on a flexible polyamide PCB. The flexible nature of the implant allows for the implant to conform to the surface of the brain. The implant requires no transcranial orifice since it is powered wirelessly and transmits data wirelessly via Bluetooth low energy. The CMOS neural amplifier chip on the implant utilizes an enhanced form of delta modulation to remove the requirement for large ADCs to be present on the die, saving space and enabling 1024 amplifiers and electrodes to be present on the chip. The implant is capable of measuring, modulating, and wirelessly transmitting a millivolt order signal to a PC for demodulation and analysis.

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Electrochemical Detection of Neurotransmitters in the Brain and Other Molecules with Biological Activity in the Nervous System: Dopamine Analysis

Current Organic Chemistry ◽

10.2174/1385272824666200204121746 ◽

2020 ◽

Vol 24 (21) ◽

pp. 2498-2507

Author(s):

Erika Bustos ◽

Juan Manríquez ◽

Ana Laura Colín-González ◽

Edgar Rangel-López ◽

Abel Santamaría

Keyword(s):

Nervous System ◽

Biological Activity ◽

Electrochemical Detection ◽

Neurological Diseases ◽

Electrochemical Techniques ◽

Modified Electrodes ◽

Analytical Techniques ◽

The Brain

Monitoring the appropriate functions of the brain is a priority when the diagnosis of neurological diseases is carried out. In this regard, there are different analytical techniques to detect neurotransmitters and other molecules with biological activity in the nervous system. Among several analytical procedures, electrochemical techniques are very important since they can be applied in situ, without loss of sensibility and/or minimal handling of samples. In addition, it is also possible to combine them with specific detectors designed on the basis of chemically-modified electrodes in order to improve detection limits by promoting molecular recognition capabilities at their surfaces, thus favoring the development of electrochemical detection in vivo by microelectrodes. In this mini-review, we will describe the major characteristics of this analytical method and its advantages for the detection of neurotransmitters (mostly dopamine) in vivo.

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Microelectrochemical Smart Needle for Real Time Minimally Invasive Oximetry

Biosensors ◽

10.3390/bios10110157 ◽

2020 ◽

Vol 10 (11) ◽

pp. 157

Author(s):

Daniela Vieira ◽

Francis McEachern ◽

Romina Filippelli ◽

Evan Dimentberg ◽

Edward J Harvey ◽

...

Keyword(s):

Minimally Invasive ◽

Real Time ◽

Surface Area ◽

Electrochemical Detection ◽

Low Cost ◽

High Surface ◽

High Surface Area ◽

Brain Dysfunction ◽

The Brain

A variety of brain disorders such as neural injury, brain dysfunction, vascular malformation, and neurodegenerative diseases are associated with abnormal levels of oxygen. Current methods to directly monitor tissue oxygenation in the brain are expensive and invasive, suffering from a lack of accuracy. Electrochemical detection has been used as an invasiveness and cost-effectiveness method, minimizing pain, discomfort, and injury to the patient. In this work, we developed a minimally invasive needle-sensor with a high surface area to monitor O2 levels in the brain using acupuncture needles. The approach was to directly etch the iron from stainless steel acupuncture needles via a controlled pitting corrosion process, obtaining a high microporous surface area. In order to increase the conductivity and selectivity, we designed and applied for the first time a low-cost coating process using non-toxic chemicals to deposit high surface area carbon nanoparticle, catalytically active laccase, and biocompatible polypyrrole. The physicochemical properties of the materials were characterized as well as their efficacy and viability as probes for the electrochemical detection of PO2. Our modified needles exhibited efficient electrocatalysis and high selectivity toward O2, with excellent repeatability. We well engineered a small diagnostic tool to monitor PO2, minimally invasive, able to monitor real-time O2 in vivo complex environments.

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Electrochemical detection of adrenaline and hydrogen peroxide on carbon nanotube electrodes

Surface Innovations ◽

10.1680/jsuin.21.00038 ◽

2022 ◽

pp. 1-7

Author(s):

Gaurang Khot ◽

Mohsen Kaboli ◽

Tansu Celikel ◽

Neil Shirtcliffe

Keyword(s):

Hydrogen Peroxide ◽

Electrochemical Detection ◽

Electrode Materials ◽

Electrochemical Sensors ◽

Carbon Electrodes ◽

Peroxide Oxidation ◽

Cyclic Voltammetric ◽

Highly Sensitive ◽

The Brain

Adrenaline and hydrogen peroxide have neuromodulatory functions in the brain and peroxide is also formed during reaction of adrenaline. Considerable interest exists in developing electrochemical sensors that can detect their levels in vivo due to their important biochemical roles. Challenges associated with electrochemical detection of hydrogen peroxide and adrenaline are that the oxidation of these molecules usually requires highly oxidising potentials (beyond 1.4 V vs Ag/AgCl) where electrode damage and biofouling are likely and the signals of adrenaline, hydrogen peroxide and adenosine overlap on most electrode materials. To address these issues we fabricated pyrolysed carbon electrodes coated with oxidised carbon nanotubes (CNTs). Using these electrodes for fast-scan cyclic voltammetric (FSCV) measurements showed that the electrode offers reduced overpotentials compared with graphite and improved resistance to biofouling. Adrenaline oxidises on this electrode at 0.75(±0.1) V and reduces back at −0.2(±0.1) V while hydrogen peroxide oxidation is detected at 0.85(±0.1) V on this electrode. The electrodes are highly sensitive with a sensitivity of 16 nA µM−1 for Adrenaline and 11 nA µM−1 for hydrogen peroxide on an 80 µm2 electrode. They are also suitable to distinguish between adrenaline, hydrogen peroxide and adenosine thus these probes can be used for multimodal detection of analytes.

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