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Nanomaterial-based electrochemical sensing of neurological drugs and neurotransmitters.

Sanghavi BJ, Wolfbeis OS, Hirsch T, Swami NS - Mikrochim Acta (2014)

Bottom Line: This results in tremendous gains in terms of sensitivity, selectivity and versatility.We focus on understanding how specific nano-sized modifiers may be applied to influence the electron transfer event to result in gains in sensitivity, selectivity and versatility of the detection system.Figureᅟ

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904 USA.

ABSTRACT

Nanomaterial-modified detection systems represent a chief driver towards the adoption of electrochemical methods, since nanomaterials enable functional tunability, ability to self-assemble, and novel electrical, optical and catalytic properties that emerge at this scale. This results in tremendous gains in terms of sensitivity, selectivity and versatility. We review the electrochemical methods and mechanisms that may be applied to the detection of neurological drugs. We focus on understanding how specific nano-sized modifiers may be applied to influence the electron transfer event to result in gains in sensitivity, selectivity and versatility of the detection system. This critical review is structured on the basis of the Anatomical Therapeutic Chemical (ATC) Classification System, specifically ATC Code N (neurotransmitters). Specific sections are dedicated to the widely used electrodes based on the carbon materials, supporting electrolytes, and on electrochemical detection paradigms for neurological drugs and neurotransmitters within the groups referred to as ATC codes N01 to N07. We finally discuss emerging trends and future challenges such as the development of strategies for simultaneous detection of multiple targets with high spatial and temporal resolutions, the integration of microfluidic strategies for selective and localized analyte pre-concentration, the real-time monitoring of neurotransmitter secretions from active cell cultures under electro- and chemotactic cues, aptamer-based biosensors, and the miniaturization of the sensing system for detection in small sample volumes and for enabling cost savings due to manufacturing scale-up. The Electronic Supporting Material (ESM) includes review articles dealing with the review topic in last 40 years, as well as key properties of the analytes, viz., pKa values, half-life of drugs and their electrochemical mechanisms. The ESM also defines analytical figures of merit of the drugs and neurotransmitters. The article contains 198 references in the main manuscript and 207 references in the Electronic Supporting Material. Figureᅟ

No MeSH data available.


Related in: MedlinePlus

(α) Fabrication procedure of a carbon paste electrode: a) Binder, b) Graphite powder, c) Homogenized carbon paste, d) Teflon micropipette tip, e) platinum wire, f) weighing paper. (β) Surface defects present in basal plane pyrolytic graphite electrode and edge plane pyrolytic graphite electrode [18, 30]. (γ) Picture of epoxy coated electrodes. (A) Epoxide CFME in the Teflon mould, (B) Epoxide CFME after removal from the Teflon mould [31]
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Fig2: (α) Fabrication procedure of a carbon paste electrode: a) Binder, b) Graphite powder, c) Homogenized carbon paste, d) Teflon micropipette tip, e) platinum wire, f) weighing paper. (β) Surface defects present in basal plane pyrolytic graphite electrode and edge plane pyrolytic graphite electrode [18, 30]. (γ) Picture of epoxy coated electrodes. (A) Epoxide CFME in the Teflon mould, (B) Epoxide CFME after removal from the Teflon mould [31]

Mentions: The following procedure is typically used for the preparation of a carbon paste electrode (CPE). First, a carbon paste is prepared by mixing graphite and binder in 60:40 or 70:30 (w/w) ratios. The binder [Fig. 2 α, (a)] can be paraffin oil or mineral oil (nujol), although ionic liquids have been employed in recent studies. This is added to the graphite powder [Fig. 2α, (b)], the paste is mixed thoroughly in a mortar and pestle and allowed to undergo self-homogenization for 24 h [Fig.2α, (c)], and the paste is then filled into a syringe or a micro-pipette [Fig. 2α, (d)]. A metallic wire [Fig. 2α, (e)] is then dissected through the paste to provide an electrical contact. Smooth and fresh electrode surfaces are obtained by squeezing out ~0.5 mm of paste from the syringe, scraping off the excess and polishing it against weighing paper [Fig. 2α, (f)] until the surface has a shiny appearance. A pictorial description of this whole process is provided in Fig. 2α.Fig. 2


Nanomaterial-based electrochemical sensing of neurological drugs and neurotransmitters.

Sanghavi BJ, Wolfbeis OS, Hirsch T, Swami NS - Mikrochim Acta (2014)

(α) Fabrication procedure of a carbon paste electrode: a) Binder, b) Graphite powder, c) Homogenized carbon paste, d) Teflon micropipette tip, e) platinum wire, f) weighing paper. (β) Surface defects present in basal plane pyrolytic graphite electrode and edge plane pyrolytic graphite electrode [18, 30]. (γ) Picture of epoxy coated electrodes. (A) Epoxide CFME in the Teflon mould, (B) Epoxide CFME after removal from the Teflon mould [31]
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4281370&req=5

Fig2: (α) Fabrication procedure of a carbon paste electrode: a) Binder, b) Graphite powder, c) Homogenized carbon paste, d) Teflon micropipette tip, e) platinum wire, f) weighing paper. (β) Surface defects present in basal plane pyrolytic graphite electrode and edge plane pyrolytic graphite electrode [18, 30]. (γ) Picture of epoxy coated electrodes. (A) Epoxide CFME in the Teflon mould, (B) Epoxide CFME after removal from the Teflon mould [31]
Mentions: The following procedure is typically used for the preparation of a carbon paste electrode (CPE). First, a carbon paste is prepared by mixing graphite and binder in 60:40 or 70:30 (w/w) ratios. The binder [Fig. 2 α, (a)] can be paraffin oil or mineral oil (nujol), although ionic liquids have been employed in recent studies. This is added to the graphite powder [Fig. 2α, (b)], the paste is mixed thoroughly in a mortar and pestle and allowed to undergo self-homogenization for 24 h [Fig.2α, (c)], and the paste is then filled into a syringe or a micro-pipette [Fig. 2α, (d)]. A metallic wire [Fig. 2α, (e)] is then dissected through the paste to provide an electrical contact. Smooth and fresh electrode surfaces are obtained by squeezing out ~0.5 mm of paste from the syringe, scraping off the excess and polishing it against weighing paper [Fig. 2α, (f)] until the surface has a shiny appearance. A pictorial description of this whole process is provided in Fig. 2α.Fig. 2

Bottom Line: This results in tremendous gains in terms of sensitivity, selectivity and versatility.We focus on understanding how specific nano-sized modifiers may be applied to influence the electron transfer event to result in gains in sensitivity, selectivity and versatility of the detection system.Figureᅟ

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904 USA.

ABSTRACT

Nanomaterial-modified detection systems represent a chief driver towards the adoption of electrochemical methods, since nanomaterials enable functional tunability, ability to self-assemble, and novel electrical, optical and catalytic properties that emerge at this scale. This results in tremendous gains in terms of sensitivity, selectivity and versatility. We review the electrochemical methods and mechanisms that may be applied to the detection of neurological drugs. We focus on understanding how specific nano-sized modifiers may be applied to influence the electron transfer event to result in gains in sensitivity, selectivity and versatility of the detection system. This critical review is structured on the basis of the Anatomical Therapeutic Chemical (ATC) Classification System, specifically ATC Code N (neurotransmitters). Specific sections are dedicated to the widely used electrodes based on the carbon materials, supporting electrolytes, and on electrochemical detection paradigms for neurological drugs and neurotransmitters within the groups referred to as ATC codes N01 to N07. We finally discuss emerging trends and future challenges such as the development of strategies for simultaneous detection of multiple targets with high spatial and temporal resolutions, the integration of microfluidic strategies for selective and localized analyte pre-concentration, the real-time monitoring of neurotransmitter secretions from active cell cultures under electro- and chemotactic cues, aptamer-based biosensors, and the miniaturization of the sensing system for detection in small sample volumes and for enabling cost savings due to manufacturing scale-up. The Electronic Supporting Material (ESM) includes review articles dealing with the review topic in last 40 years, as well as key properties of the analytes, viz., pKa values, half-life of drugs and their electrochemical mechanisms. The ESM also defines analytical figures of merit of the drugs and neurotransmitters. The article contains 198 references in the main manuscript and 207 references in the Electronic Supporting Material. Figureᅟ

No MeSH data available.


Related in: MedlinePlus