scholarly journals Cyclodextrins as Supramolecular Recognition Systems: Applications in the Fabrication of Electrochemical Sensors

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1668
Author(s):  
Bronach Healy ◽  
Tian Yu ◽  
Daniele C. da Silva Alves ◽  
Cynthia Okeke ◽  
Carmel B. Breslin
Keyword(s):  
Chiral Recognition ◽  
Electrochemical Sensors ◽  
Intramolecular Interactions ◽  
Robust Methods ◽  
Short Introduction ◽  
Reduced Graphene ◽  
Target Analytes ◽  
Recognition Systems ◽  
Covalent Interactions ◽  
Target Analyte

Supramolecular chemistry, although focused mainly on noncovalent intermolecular and intramolecular interactions, which are considerably weaker than covalent interactions, can be employed to fabricate sensors with a remarkable affinity for a target analyte. In this review the development of cyclodextrin-based electrochemical sensors is described and discussed. Following a short introduction to the general properties of cyclodextrins and their ability to form inclusion complexes, the cyclodextrin-based sensors are introduced. This includes the combination of cyclodextrins with reduced graphene oxide, carbon nanotubes, conducting polymers, enzymes and aptamers, and electropolymerized cyclodextrin films. The applications of these materials as chiral recognition agents and biosensors and in the electrochemical detection of environmental contaminants, biomolecules and amino acids, drugs and flavonoids are reviewed and compared. Based on the papers reviewed, it is clear that cyclodextrins are promising molecular recognition agents in the creation of electrochemical sensors, chiral sensors, and biosensors. Moreover, they have been combined with a host of materials to enhance the detection of the target analytes. Nevertheless, challenges remain, including the development of more robust methods for the integration of cyclodextrins into the sensing unit.

scholarly journals Graphene Oxide: A Smart (Starting) Material for Natural Methylxanthines Adsorption and Detection

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4247 ◽  
Author(s):  
Rita Petrucci ◽  
Isabella Chiarotto ◽  
Leonardo Mattiello ◽  
Daniele Passeri ◽  
Marco Rossi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Nucleic Acids ◽  
Reduced Graphene Oxide ◽  
Electrochemical Sensors ◽  
Enzymatic Digestion ◽  
Biologically Active ◽  
Polar Solvents ◽  
Dna And Rna ◽  
Reduced Graphene

Natural methylxanthines, caffeine, theophylline and theobromine, are widespread biologically active alkaloids in human nutrition, found mainly in beverages (coffee, tea, cocoa, energy drinks, etc.). Their detection is thus of extreme importance, and many studies are devoted to this topic. During the last decade, graphene oxide (GO) and reduced graphene oxide (RGO) gained popularity as constituents of sensors (chemical, electrochemical and biosensors) for methylxanthines. The main advantages of GO and RGO with respect to graphene are the easiness and cheapness of synthesis, the notable higher solubility in polar solvents (water, among others), and the higher reactivity towards these targets (mainly due to – interactions); one of the main disadvantages is the lower electrical conductivity, especially when using them in electrochemical sensors. Nonetheless, their use in sensors is becoming more and more common, with the obtainment of very good results in terms of selectivity and sensitivity (up to 5.4 × 10−10 mol L−1 and 1.8 × 10−9 mol L−1 for caffeine and theophylline, respectively). Moreover, the ability of GO to protect DNA and RNA from enzymatic digestion renders it one of the best candidates for biosensors based on these nucleic acids. This is an up-to-date review of the use of GO and RGO in sensors.

An Electrochemically Reduced Copper/Reduced Graphene Oxide Film Modified Electrode for Sensitive Non-Enzymatic Glucose Detection in Human Serum

2021 ◽  
Author(s):  
Sopit Phetsang ◽  
Pinit Kidkhunthod ◽  
Narong Chanlek ◽  
Jaroon Jakmunee ◽  
Pitchaya Mungkornasawakul ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Human Serum ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Electrocatalytic Activity ◽  
Glucose Sensor ◽  
Electrochemical Sensors ◽  
High Sensitivity ◽  
Detection Range ◽  
Reduced Graphene

Abstract Numerous studies suggest that modification with functional nanomaterials can enhance the electrode electrocatalytic activity, sensitivity, and selectivity of the electrochemical sensors. Here, a highly sensitive and cost-effective disposable non-enzymatic glucose sensor based on copper(II)/reduced graphene oxide modified screen-printed carbon electrode is demonstrated. Facile fabrication of the developed sensing electrodes is carried out by the adsorption of copper(II) onto graphene oxide modified electrode, then following the electrochemical reduction. The proposed sensor illustrates good electrocatalytic activity toward glucose oxidation with a wide linear detection range from 0.10 mM to 12.5 mM, low detection limit of 65 µM, and high sensitivity of 172 µA mM− 1 cm− 2 along with satisfactory anti-interference ability, reproducibility, stability, and the acceptable recoveries for the detection of glucose in a human serum sample (95.6–106.4%). The copper(II)/reduced graphene oxide based sensor with the superior performances is a great potential for the quantitation of glucose in real samples.

Fabrication and Characterization of Graphene-Based Electrochemical Sensors for Glucose Measurement

2015 ◽  
Vol 15 (10) ◽  
pp. 7891-7894 ◽  
Author(s):  
Minjeong Park ◽  
Hyonkwang Choi ◽  
Yunjae Park ◽  
Wookyoung Lee ◽  
Jewon Lee ◽  
...  
Keyword(s):  
Electrochemical Sensors ◽  
Reference Electrode ◽  
Chemical Vapor ◽  
Glucose Measurement ◽  
Force Microscopy ◽  
Cyclic Voltametry ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Cu Catalyst ◽  
Ft Ir

Glucose in the blood is generally measured by electrochemical method using glucose oxidase (GOx) which acts as enzymes and reduced graphene oxide (rGO) composite. The rGO, which has low dispersibility, reduces the sensing capability of sensors. In order to solve this problem, the rGO electrodes with the addition of polyvinylpyrrolidone (PVP) have been reported. However, rGO with low electrical conductivity and mobility is not compatible to the electrochemical system. In this study, graphene with excellent electrical properties was added to PVP protected rGO. The rGO was synthesized using a Hummer and Offeman's method. Graphene was synthesized using chemical vapor deposition (CVD) with a Cu catalyst. Platinum (Pt) electrodes, Ag/AgCl, and PVP protected rGO were used as working electrode, reference electrode, and counter electrode, respectively. Surface morphology and structural properties of graphene were analyzed using atomic force microscopy (AFM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). Cyclic voltametry (CV) and I-V probe station were used to analyze the performance of the electrodes. Glucose concentration was systematically varied and the reduction current was monitored using I-V probe station.

scholarly journals Recognition and Sensing of Chiral Organic Molecules by Chiral Porphyrinoids: A Review

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 204
Author(s):  
Gabriele Travagliante ◽  
Massimiliano Gaeta ◽  
Roberto Purrello ◽  
Alessandro D’Urso
Keyword(s):  
Scientific Community ◽  
Chiral Recognition ◽  
Organic Molecules ◽  
Chiral Discrimination ◽  
Spectroscopic Techniques ◽  
Chiral Molecules ◽  
Relevant Research ◽  
Non Covalent Interactions ◽  
Organic Guests ◽  
Covalent Interactions

Porphyrinoids are extremely attractive for their electronic, optical, and coordination properties as well as for their versatile substitution at meso/β-positions. All these features allow porphyrinoids to behave as chiroptical hosts for chiral recognition by means of non-covalent interactions towards chiral guests. Over the years, chiral discrimination of chiral molecules such as amino acids, alcohols, amines, hydroxy-carboxylic acids, etc. has aroused the interest of the scientific community. Hence, this review aims to report on the progress to date by illustrating some relevant research regarding the chiral recognition of a multitude of chiral organic guests through several chiral mono- and bis-porphyrins via different spectroscopic techniques.

NanoMIP-based approach for the suppression of interference signals in electrochemical sensors

The Analyst ◽  
2019 ◽  
Vol 144 (24) ◽  
pp. 7290-7295
Author(s):  
Riccardo Rapini ◽  
Francesco Canfarotta ◽  
Elisabetta Mazzotta ◽  
Cosimino Malitesta ◽  
Giovanna Marrazza ◽  
...  
Keyword(s):  
Electrochemical Detection ◽  
Electrochemical Sensors ◽  
Molecularly Imprinted ◽  
Interference Signals ◽  
Masking Agents ◽  
Molecularly Imprinted Nanoparticles ◽  
Target Analyte

Herein, we describe the use of molecularly imprinted nanoparticles (nanoMIPs) as sequestering (masking) agents, to suppress the signal coming from interfering molecules and facilitate the electrochemical detection of the target analyte.

Application of Graphene-Based Nanocomposites in Electrochemical Detection of Heavy Metal Ions

2020 ◽  
Vol 12 (3) ◽  
pp. 435-440 ◽  
Author(s):  
Xue Chen ◽  
Yongcun Pei
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Electrochemical Detection ◽  
Heavy Metal Ions ◽  
Electrochemical Sensors ◽  
Graphene Oxides ◽  
Experimental Conditions ◽  
Reduced Graphene ◽  
Reduced Graphene Oxides ◽  
Interference Tests

The purpose of this study was to explore the application of graphene-based nanocomposites in electrochemical detection of heavy metal ions. In this study, Graphene oxide (GO) was synthesized with improved Hummers method, and flower-like MoS2/rGO nanocomposite was synthesized with hydrothermal method and used as electrode modification material. In addition, scanning electron microscopy (SEM) and X-ray images were used to observe the characterization of the prepared samples and to detect the sensitivity of four heavy metal ions under optimal experimental conditions. The results showed that the reduced graphene oxides were coated with a large number of flower-like MoS2 and laid on the reduced graphene oxides. And in electrochemical experiments, adsorption experiments and interference tests, MoS2/rGO nanocomposites showed satisfactory performance for Pb(II). Therefore, this study provided a new strategy for the development of new nanocomposites composites as electrochemical sensors to detect the heavy metal ions in the aquatic environment.

scholarly journals Graphene-Oxide-Based Electrochemical Sensors for the Sensitive Detection of Pharmaceutical Drug Naproxen

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1252 ◽  
Author(s):  
Lanting Qian ◽  
Antony Raj Thiruppathi ◽  
Reem Elmahdy ◽  
Joshua van der Zalm ◽  
Aicheng Chen
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Reduced Graphene Oxide ◽  
Oxygen Content ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Sensors ◽  
Differential Pulse ◽  
Electrochemical Behaviors ◽  
Reduced Graphene ◽  
Partially Reduced Graphene Oxide

Here we report on a selective and sensitive graphene-oxide-based electrochemical sensor for the detection of naproxen. The effects of doping and oxygen content of various graphene oxide (GO)-based nanomaterials on their respective electrochemical behaviors were investigated and rationalized. The synthesized GO and GO-based nanomaterials were characterized using a field-emission scanning electron microscope, while the associated amounts of the dopant heteroatoms and oxygen were quantified using x-ray photoelectron spectroscopy. The electrochemical behaviors of the GO, fluorine-doped graphene oxide (F-GO), boron-doped partially reduced graphene oxide (B-rGO), nitrogen-doped partially reduced graphene oxide (N-rGO), and thermally reduced graphene oxide (TrGO) were studied and compared via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that GO exhibited the highest signal for the electrochemical detection of naproxen when compared with the other GO-based nanomaterials explored in the present study. This was primarily due to the presence of the additional oxygen content in the GO, which facilitated the catalytic oxidation of naproxen. The GO-based electrochemical sensor exhibited a wide linear range (10 µM–1 mM), a high sensitivity (0.60 µAµM−1cm−2), high selectivity and a strong anti-interference capacity over potential interfering species that may exist in a biological system for the detection of naproxen. In addition, the proposed GO-based electrochemical sensor was tested using actual pharmaceutical naproxen tablets without pretreatments, further demonstrating excellent sensitivity and selectivity. Moreover, this study provided insights into the participatory catalytic roles of the oxygen functional groups of the GO-based nanomaterials toward the electrochemical oxidation and sensing of naproxen.

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