Carbon Nanotube Ionic Liquid Research Articles

Retraction: Evaluation of Pt,Pd-doped, NiO-decorated, single-wall carbon nanotube-ionic liquid carbon paste chemically modified electrode: an ultrasensitive anticancer drug sensor for the determination of daunorubicin in the presence of tamoxifen.

[This retracts the article DOI: 10.3389/fchem.2020.00677.].

A novel, intelligent and computer-assisted electrochemical sensor for extraction and simultaneous determination of patulin and citrinin in apple and pear fruit samples

In this work, a novel electrochemical sensor was fabricated for simultaneous determination of patulin (PT) and citrinin (CT) in apple and pear fruit samples. A glassy carbon electrode (GCE) was modified with graphene-multiwalled carbon nanotubes-ionic liquid (Gr-MWCNTs-IL) which was used as a platform to electrochemical synthesis of molecularly imprinted polymers (MIPs) by using PT and CT as templates, maleic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross linker with the aim of preconcentration and simultaneous determination of the PT and CT. Experimental variables affecting fabrication of the structure of the sensor and hydrodynamic differential pulse voltammetric (HDPV) response of the sensor were optimized by a small central composite design and desirability function. After optimization, the HDPV responses of the sensor were calibrated by multivariate calibration methods in the ranges of 0.5–13 fM and 1.5–18 fM for PT and CT, respectively, with the help of PLS-1, RBF-PLS, rPLS, LS-SVM, and RBF-ANN with the aim of selecting the best algorithm to assist the sensor. Our results confirmed the best performance was observed from RBF-ANN which was used for the analysis of apple and pear fruit samples. Limit of detections of the sensor assisted by RBF-ANN for determination of PT and CT were 0.08 and 0.61 fM, respectively. Several commercial brands were analyzed by the use of sensor assisted by RBF-ANN and HPLC-UV, and the results confirmed performance of the sensor was admirable and comparable with the reference method with lower cost, faster response, and easier procedure which made it to be a reliable alternative method for simultaneous determination of PT and CT in real matrices.

A computer-generated plan to develop an intelligent biosensor for investigation of the inhibition of renin by aliskiren: A journey from inhibition to biosensing

For the first time, a novel electrochemical biosensor was fabricated based on modification of a rotating glassy carbon electrode with multi-walled carbon nanotubes-ionic liquid, and molecularly imprinted polymers (MIPs) in which renin (Rn), and aliskiren (AK) were used as templates. By immersion the biosensor in Rn, AK, and their binary system (AK-Rn) solutions, the species (Rn, AK, and AK-Rn) were entrapped within the pathways of the MIPs. These processes and investigation of the inhibition of the Rn by AK helped us to obtain higher electrochemical signals for a good monitorization of the system. The effects of experimental parameters on response of the biosensor to AK were optimized by a small central composite design to obtain the highest response. Hydrodynamic cyclic voltametric (HCV), hydrodynamic differential pulse voltammetric (HDPV), and hydrodynamic linear sweep voltammetric (HLSV) data obtained and recorded in order to be analyzed by classical methods and multivariate curve resolution-alternating least squares (MCR-ALS) as an advanced chemometric method. The results of molecular dockings, classical and chemometric analyses confirmed that the Rn was strongly inhibited by the AK which was good evidence to develop a novel biosensing system for determination of Rn. A novel biosensor was developed for determination of the Rn which had an acceptable performance in determination of Rn in the range of 0–9 fM. This approach opened a new way for investigation of enzymes' inhibition, and developing a new generation of electrochemical biosensors for medical and biomedical applications.

A novel and intelligent chemometric-electrochemical-enzymatic biosensing procedure and mimicking a clinical condition environment to trick the red blood cells for counting them under physiological conditions: A new connection among chemometry, electrochemistry and hematology

Here, a novel electrochemical biosensing procedure has been developed for determination of the number of red blood cells (RBCs) under physiochemical conditions based on chemometric modeling of hydrodynamic differential pulse voltammetric (HDPV), and amperometric data as responses of a modified edge plane pyrolytic graphite electrode (EPPGE). In order to obtain a good sensitivity from the EPPGE, its surface was modified with a thin layer of multiwalled carbon nanotubes-ionic liquid (MWCNTs-IL). Catalase (CAT) was immobilized onto the surface of MWCNTs-IL/EPPGE with help of nafion. The response of the biosensor was based on electrochemical reduction of oxygen of the blood samples which was enhanced by a trick based on addition of hydrogen peroxide (H2O2) to blood samples which can be reduced by the CAT to produce extra oxygen. Prior to experiments, the solution in electrochemical cell was bubbled with pure N2 to purge the oxygen in the solution, but in order to increase the selectivity of the biosensor towards detection of the oxygen obtained from the red blood cells, voltammetric responses of the biosensor were modeled by multivariate chemometric calibration methods with the help of radial basis function-partial least squares (RBF-PLS), least squares-support vector machines (LS-SVM), recursive weighted partial least squares (rPLS), ant colony optimization-mathematical pre-processing selection by genetic algorithm-sample selection through a distance-based procedure-partial least squares-1 (ACO-GA-SS-PLS1), and radial basis function-artificial neural networks (RBF-ANN) to select the best method for determination of the number of the RBCs. The results confirmed the amperometric methods modeled by RBF-ANN showed the best performance for supporting the biosensor in determination of the number of the RBCs with a performance which had an excellent compatibility with the results of a hemocytometer. The results of this study as the newest application of chemometric-electrochemical methods can make a strong connection among electrochemists, chemometricians and hematologists to expand their collaborations on determination of blood factors.

A novel electron transfer kinetic for terbutaline detection using Tio2-MWCNTs-IL modified GCE

Herein, we report a novel electrochemical detection method based on nanocomposite modified glassy carbon electrode (GCE) nano-sensor for terbutaline (TBS). Titanium oxide nanoparticles (TiO2NPs) were synthesized and the respective titanium oxide nanoparticles-multi walled carbon nanotubes-ionic liquid (TiO2-MWCNTs-IL) nanocomposite was successfully prepared. Subsequently, the surface morphology, functional groups and thermal stability of the synthesized TiO2NPs and the nanocomposite aspects were analysed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA), respectively. In addition, electrochemical characterization of the fabricated TiO2-MWCNTs-IL-GCE was examined using electrochemical impedance spectroscopy (EIS) in order to ensure the material's suitability in electro-catalytic sensing by investigating the electron transfer kinetics of the redox probe at the modified electrode-solution interface. TiO2-MWCNTs-IL-GCE exhibited excellent significant electro-catalytic activity for the electro-oxidation of TBS at optimized electrochemical experimental conditions. The reproducibility, stability as well as the detection limits were determined. A wide linear range of 0.5 μM–3.0 μM as well as limit of detection (LOD) and limit of quantification (LOQ) of 0.016 μM and 0.214 μM, respectively, were obtained and the results were compared with similarly reported electrodes for terbutaline detection. In addition, the TiO2-MWCNTs-IL-GCE sensor has superb stability, selectivity and repeatability. Moreover, the fabricated electrode was also used for determination of TBS in its drug formulation with good percentage recovery performance (93.0%–100.2%).

An intelligent and novel electrochemical biosensor for simultaneous enzymatic biosensing of cholesterol and glucose in the presence of uric acid based on first-and second-order calibration methods

In this work, for the first time, a novel electrochemical biosensor was fabricated based on modification of a glassy carbon electrode with multi-walled carbon nanotubes-ionic liquid (MWCNTs-IL) which was used as a platform to the synthesis of molecularly imprinted polymers having glucose (GL), glucose oxidase (GO), cholesterol (CL), cholesterol oxidase (CO), cholesterol esterase (CE), horse radish peroxidase (HRP), and uric acid (UA) as template molecules. For simultaneous biosensing of GL and CL, the biosensor (MIPs/MWCNTs-IL/GCE) was incubated with the enzymes and then, it was individually incubated with GL and CL. Response of the biosensor was based on the reduction of the hydrogen peroxide produced from enzymatic reactions. Individual incubation of the biosensor with GL and CL generated two very similar peaks while its incubation with both GL and CL generated a single peak which needed to be assisted by first- and second-order calibration methods to choose the best method. Second-order hydrodynamic differential pulse voltammetric data were generated and modeled by MCR-ALS, PARASIAS, and PARAFAC2 to simultaneous determination of them in the presence of UA as uncalibrated interference based on exploiting second-order advantage. Amperometric responses of the biosensor to GL and CL were also calibrated and assisted by first-order calibration methods for simultaneous determination of GL and CL in the presence of UA based on exploiting first-order advantage. The result confirmed that the biosensor assisted by second-order data modeled by MCR-ALS showed the best performance for simultaneous determination of CL and GL in the presence of UA as uncalibrated interference in both synthetic samples and human serum samples which was comparable with HPLC-UV as the reference method. It should be noted the biosensor was able to simultaneous determination of CL and GL in the ranges of 0.5–15 pM and 1–18 pM with limits of detection of 0.81 pM and 0.23 pM, respectively, and response of the biosensor was stable, selective, ultrasensitive, repeatable, and reproducible. This work as the first report chemometric assisted enzymatic biosensing of GL and CL can be continued to develop more projects for biomedical purposes.

A novel quadruple templates molecularly imprinted polymer electrochemical sensor assisted by second-order calibration methods for detection of Sustanon abuse

Sustanon (SUS) consists of testosterone propionate (TP), testosterone phenylpropionate (TPP), testosterone isocaproate (TIC) and testosterone decanoate (TD) which is generally used as a medication to treat the testosterone deficiency in men. Misuse of SUS to enhance the ability of the athletes can be a very serious risk for their health which is discouraged. Therefore, the main aim of this work was based on developing a novel biosensing system for determination of different types of testosterones in SUS to monitor it. A rotating glassy carbon electrode (GCE) was modified with fullerene C60-multiwalled carbon nanotubes-ionic liquid (C60-MWCNTs-IL) and used as the working electrode for recording second-order hydrodynamic square wave voltammetric (hydrodynamic SWV) data at different step potentials including 0.02, 0.025, 0.03, 0.035, 0.04 and 0.045 V as a sensitive method. Different types of testosterones were extracted and preconcentrated by quadruple templates molecularly imprinted polymers (QTMIPs) and they were determined by C60-MWCNTs-IL/GCE. The testosterones showed severely overlapped peaks at the surface of C60-MWCNTs-IL/GCE which were resolved by three-way calibration based on second-order hydrodynamic SWV data. Therefore, a novel sensor assisted by QTMIPs and second-order calibration methods was developed which had a very good performance for the analysis of synthetic and real matrices in simultaneous determination of TP, TPP, TIC and TD with aim of monitoring the SUS.

Ultrasensitive biosensing of thiram based on detection of the DNA damage induced by thiram: Application to investigation of protective effects of extra virgin olive oil against DNA damage

In this work, a novel electrochemical biosensor was fabricated based on modification of a glassy carbon electrode (GCE) with nafion-DNA/gold nanoparticles/poly-ethylenedioxy pyrrole/multi-walled carbon nanotubes-ionic liquid (NF-DNA/Au NPs/PEDOP/MWCNTs-IL/GCE) with the aim of amperometric detection of the DNA damage induced by thiram (TH). By incubation of the biosensor with the TH, the TH was intercalated within DNA, and the exposed DNA released negative charges at the surface of the biosensor which repelled the probe molecules and caused the amperometric response of the biosensor to be decreased. Protective effects of extra virgin olive oil (EVOO) on the DNA damage induced by the TH were investigated by recording amperometric responses of the biosensor in the presence of EVOO, and the results confirmed that the response of the biosensor didn't change to confirm the protective effects of the EVOO on preventing the DNA damage induced by the TH. A novel and sensitive electroanalytical method was developed for determination of the TH in two linear ranges including 1–6 pM and 7–10 pM based on amperometric detection of the DNA damage induced by the TH which gave a LOD of 0.31 pM. The developed methodology in this work was successful in detection of the DNA damage induced by TH, detection of protective effects of EVOO on preventing DNA damage and determination of the TH in real matrices.

Four Component One Pot Synthesis of Benzyl Pyrazolyl Coumarin Derivatives Catalyzed by Metal-Free, Heterogeneous Chitosan Supported Ionic Liquid Carbon Nanotubes

In this present communication, four component, one pot synthesis of benzyl pyrazolyl coumarin (5a-m) derivatives achieved from the condensation of phenyl hydrazine (1), ethyl acetoacetate (EAA, 2), various substituted benzaldehyde (3), and 4-hydroxy coumarin (4) in EtOH/H2O using metal-free chitosan supported ionic liquid carbon nanotubes (CSIL@CNTs, 10 mol%) as heterogeneous catalyst reflux at 50 °C for 25–30 min. The optimized conditions and excellent yields of the products were reported. All the synthesized compounds were charecterized by the spectroscopic methods. The main advantages of this reported method using CSIL@CNTs. leads to effective conversions were achieved under reflux conditions without the need of an inert atmosphere. In adition, shorter reaction time, simple work up procedure, easy preparation of the catalyst, and chemoselectivity were siginificantly recorded.

Chemometrics-assisted electrochemical biosensing of cholesterol as the sole precursor of steroids by a novel electrochemical biosensor

This project was performed with the aims of increasing the sensitivity of differential pulse voltammetry (DPV) which itself is a sensitive electroanalytical technique, and also to compare the area under peak (univariate calibration), height of peak (univariate calibration) and whole of vector (multivariate calibration) for calibration purposes. These topics were investigated by fabrication of a novel electrochemical biosensor for determination of cholesterol (CHO). The procedure used in this project was based on the synthesis of molecularly imprinted polymers (MIPs) to the preconcentration of CHO and its biosensing by a rotating glassy carbon electrode (GCE) modified by co-immobilization of cholesterol oxidase (CO), cholesterol esterase (CE) and horseradish peroxidase (HP) onto multiwalled carbon nanotubes-ionic liquid (COCEHP/MWCNTs-IL/GCE). The results showed that the hydrodynamic DPV (HYDPV) was much more sensitive than DPV and using the area under peak for univariate calibration purposes was more suitable than height of peak. Adsorption at the electrode surface is an important trouble which affects the height and position of voltammetric peaks, but the area under peak is not affected by adsorption therefore, it can be more suitable for univariate calibration purposes. The biosensor response was also calibrated by chronoamperometry and the results confirmed that the HYDPV was more sensitive than chronoamperometry. The next attempt was based on recording the biosensor responses based on second-order HYDPV data and modeling of them (whole of vectors) by three-way calibration methods which showed the best performance among the tested methods for determination of CHO. The biosensor response was long-term stable, repeatable and reproducible which was successfully applied to the analysis of serum sample towards determination of CHO whose results were comparable with a reference method.

(Invited) Sustainable Generator and in-Situ Monitor for Reactive Oxygen Species Using Photodynamic Effect of Single-Walled Carbon Nanotubes in Ionic Liquids

Due to the demand of public health maintenance, disinfectant generator technologies that utilize green processes are becoming attractive. It has been confirmed that single-walled carbon nanotubes (SWCNTs) could generate reactive oxygen species (ROS) in water when illuminated with solar irradiation. However, low efficiency due to the competitive reactions between ROS and water in aqueous media and unclear kinetics hinder their potential practical applications. To overcome these limitations, here, the SWCNTs were studied in a nonaqueous ionic liquid (IL) to form a suspension system to generate superoxide (O2 -) under UV light. The as-obtained O2 - from SWCNTs was qualitatively confirmed by electron paramagnetic resonance and UV-visible spectroscopy. The sustainability of the new SWCNTs/IL system was confirmed by UV-visible spectroscopy and Fourier-transform infrared spectroscopy. The IL proved to be an ideal media that could extend the duration of O2 - from a few microseconds (commonly generated in the water) to at least 65 hours in the IL. The kinetics of photodynamic effect was investigated by electrochemical characterizations. A new method was established to in-situ monitor the O2 - level in the IL system. The O2 - level in the IL was quantitatively determined by combining cyclic voltammetry and chronoamperometry techniques. The SWCNTs/IL system generated 4.11 mM of O2 - in a mini-scale generator, which was excessive to germicidal levels for ROS. The sustainable, long duration and high-yield of the generator exhibited an excellent potential as a generator as well as an in-situ monitor for O2 -. This work could pave the way for O2 - generation using SWCNTs and promote its applications in air and water disinfection for public health, as well as O2 - sensitive chemical sensors for monitoring environmental quality.

A novel dual template molecularly imprinted modified pencil graphite electrode and assisting it by second-order calibration to construct a novel electronic device in advance for simultaneous determination of ferritin and transferrin

This work introduced a novel electronic device for simultaneous determination of ferritin and transferrin in real matrices. Here, a pencil graphite electrode was chosen as a platform and its surface was modified with multiwalled carbon nanotubes-ionic liquid and electrochemically reduced fullerene-C60. Finally, the surface of the biosensor was modified by dual template molecularly imprinted polymers which were produced by electropolymerization of 2-amino-5-mercapto-1, 3, 4-thiadiazole, and ferritin and transferrin as template molecules. To generate a square wave voltammetric signal from the biosensor to simultaneous determination of ferritin and transferrin, it was incubated into a solution having ferritin and transferrin and then, it was immersed into an electrochemical probe solution. By incubation of the biosensor with ferritin and transferrin, the pathways within its molecularly imprinted polymer layer were occupied by ferritin and transferrin therefore, it was reasonable to observe decreasing of the height of its square wave voltammetric response. Because of the nature of the square wave voltammetric data (potential shifts), incubation of the biosensor with ferritin and transferrin produced two severely overlapped peaks while incubation of the biosensor with both of them generated a single peak. Therefore, for simultaneous determination of ferritin and transferrin, the biosensor was assisted by three-way calibration with the help of second-order square wave voltammetric data which helped me to develop a very efficient electronic device for simultaneous determination of ferritin (sensitivity: 6.5 ​μA ​nM−1, limit of detection: 0.01 ​nM) and transferrin (sensitivity: 6.1 ​μA ​nM−1, limit of detection: 0.012 ​nM) in serum samples whose performance was comparable with a reference method.

Sustainable generator and in-situ monitor for reactive oxygen species using photodynamic effect of single-walled carbon nanotubes in ionic liquids

Due to the increasing concerns regarding public health and climate change, disinfectant generator technologies that utilize green processes are becoming necessary. It has been confirmed that single-walled carbon nanotubes (SWCNTs) can generate reactive oxygen species (ROS) in aqueous media when illuminated with solar irradiation. However, low efficiency due to competitive reactions between ROS and water and unclear kinetics hinder their potential practical applications. To overcome these limitations, here, SWCNTs were studied in a non-aqueous ionic liquid (IL) to form a suspension system for generating superoxide (O2−) under UV light. The as-obtained O2− from SWCNTs was qualitatively confirmed by electron paramagnetic resonance and UV–vis spectroscopy. The sustainability of the new SWCNTs/IL system was confirmed by UV–vis and Fourier-transform infrared spectroscopy. The IL proved to be an ideal media that could extend the lifetime of O2− from a few microseconds (generated in water) to at least 65 h in the IL. The kinetics of photodynamic effect were investigated by electrochemical characterizations. A new method was established to in-situ monitor the O2− level in the IL system. The O2− level in the IL was quantitatively determined by combining cyclic voltammetry and chronoamperometry techniques. The SWCNTs/IL system generated 4.11 mM of O2− in a mini-scale generator, which was in excess of germicidal levels for ROS. The sustainable, long duration and high-yield of the generator exhibited excellent potential as a generator as well as an in-situ monitor for O2−. This work could pave the way for O2− generation using SWCNTs and promote its applications in air and water disinfection for public health, as well as O2− sensitive chemical sensors for monitoring the environmental quality.

Ionic Liquid-Multiwalled Carbon Nanotubes Nanocomposite Based All Solid State Ion-Selective Electrode for the Determination of Copper in Water Samples

A new copper sensitive all solid-state ion-selective electrode was prepared using multiwalled carbon nanotubes-ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) nanocomposite as an additional membrane component. The effect of nanocomposite content in the membrane on the electrode parameters was investigated. The study compares, among others, detection limits, sensitivity, and the linearity ranges of calibration curves. Content 6 wt.% was considered optimal for obtaining an electrode with a Nernstian response of 29.8 mV/decade. An electrode with an optimal nanocomposite content in the membrane showed a lower limit of detection, a wider linear range and pH range, as well as better selectivity and potential stability compared to the unmodified electrode. It was successfully applied for copper determination in real water samples.

Comparative study of nitrate all solid state ion-selective electrode based on multiwalled carbon nanotubes-ionic liquid nanocomposite

Carbon nanotubes have enjoyed unflagging popularity in recent years. They are successfully used in many fields of science, including potentiometry for the construction of ion selective electrodes with solid contact. A new type of SC-ISEs sensitive to nitrate(V) ions using multiwalled carbon nanotubes-ionic liquid nanocomposite was prepared. The effect of the kind of carbon nanotubes on the parameters of SC-ISEs was investigated. The study compares, among others, detection limits, sensitivity and linearity ranges of characteristic curves, and stability of the potential measured for the tested electrodes. Electrochemical impedance spectroscopy and chronopotentiometric techniques were also used as research methods. It was found that the type of carbon nanotubes included in the nanocomposite influences both the metrological and electrical parameters of the obtained solid contact nitrate ion-selective electrode.

Evaluation of Pt,Pd-Doped, NiO-Decorated, Single-Wall Carbon Nanotube-Ionic Liquid Carbon Paste Chemically Modified Electrode: An Ultrasensitive Anticancer Drug Sensor for the Determination of Daunorubicin in the Presence of Tamoxifen.

Measuring the concentration of anticancer drugs in pharmacological and biological samples is a very useful solution to investigate the effectiveness of these drugs in the chemotherapy process. A Pt,Pd-doped, NiO-decorated SWCNTs (Pt,Pd-NiO/SWCNTs) nanocomposite was synthesized using a one-pot procedure and combining chemical precipitation and ultrasonic sonochemical methods and subsequently characterized by TEM and EDS analysis methods. The analyses results showed the high purity and good distribution of elements and the ~10-nm diameter of the Pt,Pd-NiO nanoparticle decorated on the surface of the SWCNTs with a diameter of about 20–30 nm. Using a combination of Pt,Pd-NiO/SWCNTs and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (1B23DTFB) in a carbon paste (CP) matrix, Pt,Pd-NiO/SWCNTs/1B23DTFB/CP was fabricated as a highly sensitive analytical tool for the electrochemical determination of daunorubicin in the concentration range of 0.008–350 μM with a detection limit of 3.0 nM. Compared to unmodified CP electrodes, the electro-oxidation process of daunorubicin has undergone significant improvements in current (about 9.8 times increasing in current) and potential (about 110 mV) decreasing in potential). It is noteworthy that the designed sensor can well measure daunorubicin in the presence of tamoxifen (two breast anticancer drugs with a ΔE = 315 mV. According to the real sample analysis data, the Pt,Pd-NiO/SWCNTs/1B23DTFB/CP has proved to be a promising methodology for the analysis and measuring of daunorubicin and tamoxifen in real (e.g., pharmaceutical) samples.

Fabrication of a novel amperometric sensing platform for determination of mangiferin

In this work, we have fabricated a novel amperometric platform for the sensing of mangiferin (MAG) based on application of an interesting modification strategy to a bare glassy carbon electrode (GCE). The first layer of the modification process consisted of loading of multiwalled carbon nanotubes-ionic liquid (MWCNTs-IL) onto the GCE surface which was then, modified with reduced fullerene C60 (C60). The C60/MWCNTs-IL/GCE was further modified with chitosan-IL (CS-IL) which was an excellent platform for electrodeposition of the Au and Pt nanoparticles (AuPt NPs). Our modification procedure allowed us to obtain AuPt NPs/CS-IL/C60/MWCNTs-IL/GCE as the sensing platform for determination of MAG in real samples. After characterization and confirmation of the modification process, the sensor response to MAG was calibrated by standard solutions which showed us that the sensor response was linear in the concentration range of 2–40 nM with a detection limit of 0.61 nM. After that, the sensor was applied to the determination of MAG in spiked human plasma samples which confirmed the capability of the sensor for determination of MAG in real samples. Our results confirmed that the sensor response was repeatable, reproducible, selective, sensitive and stable towards determination of MAG.

On Supramolecular Polymerization: Interview with Takuzo Aida.

Prof. Takuzo Aida is one of the most visible materials chemists thanks to his many creative contributions to the broad field of supramolecular chemistry. Over the past two decades he has ingeniously utilized self-assembly across scales and between various components to access a breathtaking variety of complex materials with fascinating properties. For example, the Aida Lab has pioneered conducting "bucky gel" by dispersing carbon nanotubes in ionic liquids as well as "aqua materials", in which a tiny amount of additive renders water mechanically robust. From his personal insight he shares in this Interview, we can learn how his research evolved since his undergraduate studies. Moreover, he shares his vision on the importance of supramolecular polymers (Supra-Plastics) to realize a sustainable society.

Chemometrical-electrochemical investigation for comparing inhibitory effects of quercetin and its sulfonamide derivative on human carbonic anhydrase II: Theoretical and experimental evidence

This paper reports results of a valuable study on investigation of inhibitory effects of the sulfonamide derivative of quercetin (QD) on human carbonic anhydrase II (CA-II) by electrochemical and chemometrical approaches. To achieve this goal, a glassy carbon electrode (GCE) was chosen as the sensing platform and different electrochemical techniques such as cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were used to investigate and comparing inhibitory effects of quercetin (Q) and QD on CA-II. By the use of EQUISPEC, SPECFIT, SQUAD and REACTLAB as efficient hard-modeling algorithms, bindings of Q and QD with CA-II were investigated and the results confirmed that the QD inhibited the CA-II stronger than Q suggesting a highly relevant role of QD's-SO2NH2 group in inhibiting activity and also was confirmed by docking studies. Finally, a novel EIS technique based on interaction of Q and CA-II was developed for sensitive electroanalytical determination of CA-II and in this section of our study, the sensitivity of the developed electroanalytical methodology was improved by the modification of the GCE was with multi-walled carbon nanotubes-ionic liquid.

Highly Conductive Crown Ether/Ionic Liquid Crystal-Carbon Nanotubes Composite Based Electrochemical Sensor for Chiral Recognition of Tyrosine Enantiomers

A new insight is presented in the fabrication of a simple chiral electrochemical sensor for tyrosine enantiomers which are the biomarkers of depression. The conductive sensor is based on modifying the glassy carbon electrode with two consecutive layers namely multi-walled carbon nanotubes-ionic liquid crystal (CNT+ILC) and 18-crown-6 (CW); GC/(CNT+ILC)/CW. CW is introduced for the first time as an excellent receptor for the chiral recognition of Ty enantiomers due to its perfect host-guest size matching principle. On the other hand, β-cyclodextrin (β-CD) does not recognize Ty enantiomers as its cavity size was larger, and needs extra modifications. Moreover, it was observed due to the opposite steric configurations of the Ty enantiomers, CW preferably forms strong complexes with L-Ty compared to D-Ty enantiomers, resulting in significantly noticeable electrochemical differences in their peak current responses with ratio of (L-Ty to D-Ty) about 3.09. The GC/(CNT+ILC)/CW showed excellent current responses for the electrochemical analysis of L-Ty and D-Ty enantiomers in the concentration ranges of 0.01–60 μmol L−1 and 0.09–60 μmol L−1 with low detection limit values of 1.42 nmol L−1and 9.36 nmol L−1, respectively. The practical impact of the sensor was illustrated in accurate determination of the percentage of enantiomers in Ty racemic mixture. Moreover, the electro-oxidation of AA, UA, and L-Ty in their ternary mixture was successfully achieved to three well-separated peaks using the GC/(CNT+ILC)/CW sensor.