Applications of Chemometrics‐Assisted Voltammetric Analysis

Electroanalytical techniques consist of the interplay between electricity and chemistry, namely the measurement of electrical quantities, such as charge, current or potential and their relationship to chemical parameters. Electrical measurements for analytical purposes have found a lot of applications including industry quality control, environmental monitoring and biomedical analysis. Chemometrics is the chemical discipline that uses mathematical and statistical methods to design or select optimal procedures and experiments and to provide maximum chemical information by analysing chemical data. The use of chemometrics in electroanalytical chemistry is not as popular as in spectroscopy, although recently, applications of these methods for mathematical resolution of overlapping signals, calibration and model identification have been increasing. The electroanalytical methods will be improved with the application of chemometrics for simultaneous quantitative prediction of analytes or qualitative resolution of complex overlapping responses. This chapter focuses on applications of first-, second- and third-order multivariate calibration coupled with voltammetric data for quantitative purposes and has been written from both electrochemical and chemometrical points of view with the aim of providing useful information for the electrochemists to promote the use of chemometrics in electroanalytical chemistry

Matrix augmentation as an efficient method for resolving interaction of bromocriptine with human serum albumin: trouble shooting and simultaneous resolution

This work reports the results of an interesting study related to the investigation of interactions of bromocriptine (BCP) with human serum albumin (HSA) by mathematicall modelling of voltammetric and spectroscopic data into an augmented data matrix and its resolution by multivariate curve resolution-alternating least squares (MCR-ALS). The quality of the results obtained by MCR-ALS was examined by MCR-BANDS and its outputs confirmed the absence of rotational ambiguities in the MCR-ALS results. BCP-HSA interactions were also modeled by molecular docking methods to verify the results obtained from experimental sections and fortunately, they were compatible. Hard modeling of the experimental data by EQUISPEC helped us to calculate the binding constant of the complex formed from BCP-HSA interactions which was in a good agreement with that of calculated from direct analysis of the experimental data. Finally, with the help of two different amperometric measurements based on BCP-HSA interactions a novel electroanalytical method was developed for biosensing of HSA in serum samples.Fil: Jalalvand, Ali R.. Kermanshah University of Medical Sciences; IránFil: Ghobadi, Sirous. Kermanshah University of Medical Sciences; IránFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Faramarzi, Elahe. Kermanshah University of Medical Sciences; IránFil: Mahmoudi, Majid. Kermanshah University of Medical Sciences; Irá

An elegant technology for ultrasensitive impedimetric and voltammetric determination of cholestanol based on a novel molecularly imprinted electrochemical sensor

In this work, a novel molecularly imprinted electrochemical sensor (MIES) has been fabricated based on electropolymerization of a molecularly imprinted polymer (MIP) onto a glassy carbon electrode (GCE) modified with gold-palladium alloy nanoparticles (AuPd NPs)/polydopamine film (PDA)/multiwalled carbon nanotubes-chitosan- ionic liquid (MWCNTs-CS-IL) for voltammetric and impedimetric determination of cholestanol (CHO). Modifications applied to the bare GCE formed an excellent biocompatible composite film which was able to selectively detect CHO molecules. Modifications applied to the bare GCE were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (SEM). Under optimal experimental conditions, the sensor was able to detect CHO in the range of 0.1-60 pM and 1-50 pM by EIS and DPV, respectively. Moreover, the sensor showed high sensitivity, selectivity, repeatability, reproducibility, low interference and good stability towards CHO determination. Our records confirmed that the sensor was successfully able to the analysis real samples for determination of CHO

Mathematical modeling of interactions of cabergoline with human serum albumin for biosensing of human serum albumin

In this work, we are going to study the interactions of cabergoline (CBG) with human serum albumin (HSA) by mathematical modeling of voltammetric and spectroscopic data. To achieve this goal, voltammetric and spectroscopic data will be augmented into a data matrix which will be resolved by multivariate curve resolution-alternating least squares (MCR-ALS) as a powerful chemometric tool. Then, the quality of the data fitting by MCR-ALS will be examined by MCR-BANDS to ensure about the absence of the rotational ambiguities in the results. Molecular docking will also be used to model the interactions of CBG with HSA for verifying the results obtained from experimental methods. Hard-modeling of the experimental data will be performed by EQUISPEC to compute the binding constant of the complex formed from the interactions of CBG with HSA for verifying the binding constant obtained by direct analysis of the experimental data. Finally, two chrono-amperometric measurements based on CBG-HSA interactions will be performed to develop a novel electroanalytical method for determination of electro-inactive HSA.Fil: Jalalvand, Ali R.. Kermanshah University of Medical Sciences; IránFil: Ghobadi, Sirous. Razi University; IránFil: Akbari, Vali. Razi University; Irán. Kermanshah University of Medical Sciences; IránFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Faramarzi, Elahe. Kermanshah University of Medical Sciences; IránFil: Mahmoudi, Majid. Kermanshah University of Medical Sciences; Irá

The first attempt on fabrication of a nano-biosensing platform and exploiting first-order advantage from impedimetric data: application to simultaneous biosensing of doxorubicin, daunorubicin and idarubicin

In this work, for the first time, we have developed a novel and very interesting electroanalytical methodology assisted by first-order multivariate calibration (MVC) for simultaneous determination of doxorubicin (DX), daunorubicin (DN) and idarubicin (ID) as three chemotherapeutic drugs at simulated physiological conditions. A sever overlapping was observed among signals of the three drugs which hindered us for simultaneous determination of them by conventional electroanalytical techniques. Therefore, we had to assist our method by chemometric approaches to develop a novel method for simultaneous determination of DX, DN and ID. Among the existing electroanalytical methods, electrochemical impedance spectroscopy (EIS) due to its high sensitivity was chosen. After individual calibration of the three drugs with the EIS data, a set of calibration samples was designed which was used to develop several first-order MVC models by partial least squares (PLS), continuum power regression (CPR), radial basis function-partial least squares (RBF-PLS), RBF-artificial neural network (RBF-ANN) and least squares-support vector machines (LS-SVM) as linear and non-linear chemometric algorithms. Then, performance of the developed MVC models in predicting concentrations of DX, DN and ID in synthetic samples was compared to choose the best model for the analysis of real samples. Our records confirmed more superiority of RBF-PLS algorithm than the other developed models which motivated us to choose it for the analysis of real samples. Fortunately, the results of the RBF-PLS in the analysis of real samples towards simultaneous determination DX, DN and ID was acceptable.Fil: Soleimani, Shokoufeh. Kermanshah University Of Medical Sciences; IránFil: Arkan, Elham. Kermanshah University Of Medical Sciences; IránFil: Farshadnia, Tooraj. Kermanshah University Of Medical Sciences; IránFil: Mahnam, Zahra. Kermanshah University Of Medical Sciences; IránFil: Jalili, Faramarz. Kermanshah University Of Medical Sciences; IránFil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Desarrollo Analítico y Quimiometría; ArgentinaFil: Jalalvand, Ali R.. Kermanshah University Of Medical Sciences; Irá

Evaluation of Antimicrobial and Wound Healing Effects of Gold Nanoparticles Containing Abelmoschus esculentus (L.) Aqueous Extract

Background. Wound healing is a complex process of replacing devitalized cellular structures and tissues with healthy cells and tissue. Nanotechnology has been increasingly proposed as a novel platform to treat wounds and skin regeneration. The aim of this study was to evaluate the antibacterial, antioxidant, cytotoxic, and cutaneous wound healing activities of phytosynthesized Au NPs using Abelmoschus esculentus (okra) and synthesized Au NPs by using the citrate synthesis method. The Ok Au NPs were characterized using various techniques like UV-Vis absorption spectroscopy, FTIR, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Cutaneous wounds were created on 30 rats and randomized into three groups: untreated and two groups treated with Ch Au NPs and Ok Au NPs. The treatment was carried out daily for 12 days. A peak characterized the Ok Au NPs at 538 nm in the UV-Vis spectrum. Based on the results of FTIR spectroscopy, various functional oxygenated groups such as hydroxyl, carboxyl, and nitrogenous groups were observed. XRD confirmed the crystalline nature of the nanoparticles. TEM images of Ok Au NPs showed a spherical shape and size range of 75 nm. DPPH test showed similar antioxidant potentials for Au NPs. The Au NPs showed cell viability in a dose-dependent manner, and this technique was found to be nontoxic. Agar well diffusion, which is the method to determine antibacterial characteristics of Au NPs, showed a significant beneficial effect against a variety of bacterial species. In addition, histopathological results showed that Au NPs could accelerate wound closure. Therefore, Au NPs could be suitable for wound healing applications

Investigating the fatigue behaviour of quasi-isotropic pseudo-ductile thin-ply carbon/glass epoxy hybrid composites

This paper investigates the fatigue behaviour of pseudo-ductile Quasi-Isotropic (QI) interlayer hybrids with un-notched and open-hole configurations. Two different types of QI pseudo-ductile hybrids were evaluated; HighC, with carbon to glass thickness ratio of 0.29, that is made of thin-ply M46JB-carbon/epoxy and thin-ply Xstrand-glass/epoxy prepregs, and LowC, with carbon to glass thickness ratio of 0.19, that is made of thin-ply T300-carbon/epoxy and standard-ply S-glass/epoxy prepregs. The hybrid configurations were loaded at 4 Hz in tension–tension fatigue without any initial damage and at different percentages of the pseudo-yield stress (σpy) at which damage initiates. It was observed that there is no stiffness reduction, after 100000 cycles, for a stress level of 80% and 50% of the σpy for the un-notched and open-hole laminates, respectively. By increasing the stress level to 90% and 70% of the σpy for the un-notched and open-hole laminates, respectively, there is a gradual stiffness reduction due to the appearance of matrix cracking and delamination in LowC, but no gradual reduction and no visible damage were observed for HighC. The final failure is more brittle and happens at a lower number of cycles for HighC compared with LowC. Different damage extents were observed for the investigated laminates before the final sudden failure due to variables such as the ply thickness, the cyclic energy release rate and the interfacial fracture toughness

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

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

A novel amperometric biosensor for multi-enzymatic biosensing of triglycerides

This work has been focused on developing a novel biosensor assisted by multivariate calibration methods to determine triglycerides (TGs, triacetin, tributyrin, tricaproin, tricaprylin, and tricaprin) in lyophilized serum samples. To achieve this goal, a bare glassy carbon electrode (GCE) was modified and used as the biosensing platform. To increase the sensitivity of the developed method, hydrodynamic methods were used to calibrate the biosensor response. To increase the selectivity of the developed biosensor, it was assisted by partial least squares-1 (PLS-1), radial basis function-PLS (RBF-PLS), and RBF-artificial neural network (RBF-ANN) for exploiting first-order advantage. After characterization of the modifications, the first-order advantage was exploited to increase the selectivity of the method by building a multivariate calibration set in a pre-analyzed lyophilized serum with different TGs concentrations, which were chosen according to the individual calibration curve. Calibration models were then built in the same pre-analyzed lyophilized serum and analyzed by PLS-1, RBF-PLS, and RBF-ANN. Therefore, their performances were examined to predict concentrations of a validation set. The results confirmed the successfulness of the calibration model developed by RBF-ANN. Finally, it was used to analyze two serum samples, and the results demonstrated that the method was successful because its results were compared with a reference method