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In this work, we report the synthesis of a mono metallic supramolecular polymer for constructing a new nonenzymatic electrochemical nitrite sensor. Metallo supramolecular polymer have been prepared by the complexation reaction of a ligand bearing terpyridine moieties [4′,4′′′′-(1,4 Phenylene) bis (2,2′:6′,2′′-terpyridine] with Fe(II) salts (Fe salt: Ligand-1:1) (polyFe). The polyFe was characterized with the UV/Vis titration and FTIR. The glassy carbon electrode (GCE) was used for fabricating ployFe_GCE via a drop casting method that was used for detecting nitrite through the oxidation process. The kinetics of the irreversible oxidation mechanism was studied using scan rate. Amperometry and CV techniques were used for studying the effectiveness of the polyFe_GCE for detecting nitrite at different concentrations. The polyFe_GCE was also used for interference, reproducibility, and stability study. We utilized the proposed sensor further for analyzing nitrite in tap water. The recovery obtained was satisfactory with relatively low value of standard deviation.

Glucose detection is considered a significant area and has remained the topic of considerable attention. Remarkable technological advancements have been observed in diabetes monitoring in the past decades. This continual progress helps to track recent trends in development as well as identify challenging issues in glucose sensor construction. Thus, a comprehensive synopsis of the most recent advancements and developments in the study of nickel (Ni) nanostructure-based sensors for efficient trace-level glucose detection, following non-enzymatic and electrochemical methods, is provided in this review. Moreover, this review is intensively focused on the methodologies for the structure, morphology, preparation, and enforcement of a variety of Ni nanostructures, including Ni nanosheets with metals, Ni nanospheres with metals/mixed metals, Ni-metal nanocomposites, metal nanoparticles-decorated Ni nanowires, Ni nanoparticles, Ni-decorated metal nanotube arrays, Ni nanoneedles and nanorods with metals, nanoporous, nanoplates, nanocoated Ni with metal composites, and Ni-composed hybrid nanostructures. Various demonstrations and categorizations are provided on Ni-based nanostructures for a clear understanding for diverse readers.

Nitrite is one of the abundant toxic components existing in the environment and is likely to have a great potential to affect human health badly. For that reason, it has become crucial to build a reliable nitrite detection method. In recent years, several nitrite monitoring systems have been proposed. Compared with traditional analytical strategies, the electrochemical approach has a bunch of advantages, including low cost, rapid response, easy operation, simplicity, etc. In this case, noble metal nanomaterials, especially Au-based nanomaterials, have attracted attention in electrode modification because of higher catalytic activity, facile mass transfer, and broad active area for determining nitrite. This review is based on the state-of-the-art, which includes a variety of nanomaterials that have been coupled with gold nanoparticles (AuNPs) for the creation of nanocomposites, and the construction as well as development of electrochemical sensors for nitrite detection over the last few years (2016-2022). A background study on synthesizing different morphological AuNPs and nanocomposites has also been introduced. The fabrication methods and sensing capabilities of modified electrodes are given special consideration.

The rising energy crisis and environmental concerns caused by fossil fuels have accelerated the deployment of renewable and sustainable energy sources and storage systems. As a result of immense progress in the field, cost-effective, high-performance, and long-life rechargeable batteries are imperative to meet the current and future demands for sustainable energy sources. Currently, lithium-ion batteries are widely used, but limited lithium (Li) resources have caused price spikes, threatening progress toward cleaner energy sources. Therefore, post-Li, batteries that utilize highly abundant materials leading to cost-effective energy storage solutions while offering desirable performance characteristics are urgently needed. Aluminum-ion battery (AIB) is an attractive concept that uses highly abundant aluminum while offering a high theoretical gravimetric and volumetric capacity of 2980 mAh g

As the world moves towards renewable and sustainable energy sources, the need for systems that can quickly and safely store this energy is also rising. Supercapacitors (SCs) are among the most promising alternatives to conventional lithium-ion batteries. SCs are more stable, have higher-power densities, and can be charged much faster. However, SCs have their issues, and three of the main drawbacks of current SCs are 1) lower energy densities, 2) high cost of production, and 3) safety concerns in wearable devices. In this review, we discuss recent progress made in supramolecule-based SCs (SSCs). In supramolecular systems, molecules are held stable using non-covalent-type bonds. This allows for a flexible system in which the molecular interaction sites can easily break and reform at low energy, allowing for exposure of highly active sites and self-healing. When heterometal atoms are introduced into these supramolecular systems, this allows for further activation of the metal sites through the metal-metal interaction along with the metal-ligand interactions. This review discusses different types of SSCs (carbon-based and metal-incorporated) that have been utilized in recent years depending on their synthesis process. The working principle of SSCs and the utilization of different supramolecular elements that enhance the performance of SCs have also been discussed.

The demand for energy storage devices with high energy and power densities has increased tremendously in this rapidly growing world. Conventional capacitors, fuel cells, and lithium-ion batteries have been used as energy storage devices for the long term. However, supercapacitors are one of the most promising energy storage devices because of their high specific capacitance, high power density, and longer cycle life. Recent research has focused on synthesizing transition-metal oxides/hydroxides, carbon materials, and conducting polymers as supercapacitor electrode materials. The performance of supercapacitors can be improved by altering electrolytes, electrode materials, current collectors, experimental temperatures, and film thickness. Thousands of papers on supercapacitors have already been published, reflecting the significance and elucidating how much demanding such energy storage devices for this fast-growing generation. This review aims to illustrate the electrode materials loaded on various conductive substrates by electrochemical deposition employed for supercapacitors to provide broad knowledge on synthetic pathways, which will pave the way for future research. We also discussed the basic parameters involved in supercapacitor studies and the advantages of the electrochemical deposition techniques through literature analysis. Finally, future trends and directions on exploring metals/metal composites toward designing and constructing viable, high-class, and even newly featured flexible energy storage materials, electrodes, and systems are presented.

Here, a monometallic supramolecular polymer (SMP) was synthesized for the fabrication of an electrochemical nitrite sensor, and a mechanism for nitrite detection was proposed based on the experimental findings. The SMP (polyFe) was synthesized using a symmetrical ligand containing terpyridine moieties [4′,4′′′′-(1,4- Phenylene) bis(2,2′:6′,2′′-terpyridine)] and ferrous acetate. Various analytical methods, such as ultraviolet/visible (UV/Vis) titration, field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS), were used to characterize polyFe. The molecular weight of polyFe was calculated from the intrinsic viscosity measurement using the Mark-Houwink-Sakurada equation. The electrochemical behavior of the fabricated sensor was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The variation in scan rate from CV was used to investigate the kinetics of nitrite oxidation. A possible reaction mechanism was proposed based on the kinetic studies. The proposed sensor showed a good linear range of 2.49 μM to 1.23 mM and a limit of detection of 0.17 μM. Stability, interference, and reproducibility of the proposed sensor were also investigated. The CV technique was used to demonstrate the applicability of the nitrite sensor for real sample analysis. A satisfactory recovery with a low relative standard deviation was achieved.

Electrochemical capacitors, also known as supercapacitors (SCs), have lately played an important role in energy storage and conversion systems due to their specific characteristics such as high strength, durability, and environmental friendliness. A wide range of materials is used as electrodes for SC applications because the electrochemical efficiency is primarily determined by the electrode materials used. Carbonaceous materials with unique surface, chemical, electrochemical, and electronic characteristics have become attractive for energy storage research, but they cannot meet the rising need for high specific energy and specific power. Besides, heteroatom-doped carbon materials have shown pseudocapacitance characteristics and improved specific energy, specific power, and conductivity. This makes them more adaptable in SC application. Among different heteroatom doping of carbon, S-doped carbon has gained considerable attention in SC applications due to its unpaired electrons and easily polarizable nature. S-doped carbon materials-based SCs have demonstrated enhanced surface wettability, improved conductivity, and induced pseudocapacitance effect, thereby delivering improved specific energy and specific power. Many reports on S-doped carbon for SC applications have been published, but there is no specific Review on the preparation of S-doped carbon for SC applications. This Review focuses on recent developments in the field of SC electrodes made from S-doped carbon materials. Herein, the preparation methods and applications of S-doped carbon for SCs were summarized following a brief discussion of different electrochemical characterization techniques of SCs. Finally, the challenges of S-doped carbon materials and their potential prospects were discussed to give crucial insights into the favorable factors for future innovations of SC electrodes. This Review aims to provide insight for further research on the preparation of S-doped carbon for electrochemical energy storage applications.

Dopamine (DA) is an important neurotransmitter, which is created and released from the central nervous system. It plays a crucial role in human activities, like cognition, emotions, and response to anything. Maladjustment of DA in human blood serum results in different neural diseases, like Parkinson's and Schizophrenia. Consequently, researchers have started working on DA detection in blood serum, which is undoubtedly a hot research area. Electrochemical sensing techniques are more promising to detect DA in real samples. However, utilizing conventional electrodes for selective determination of DA encounters numerous problems due to the coexistence of other materials, such as uric acid and ascorbic acid, which have an oxidation potential close to DA. To overcome such problems, researchers have put their focus on the modification of bare electrodes. The aim of this review is to present recent advances in modifications of most used bare electrodes with carbonaceous materials, especially graphene, its derivatives, and carbon nanotubes, for electrochemical detection of DA. A brief discussion about the mechanistic phenomena at the electrode interface has also been included in this review.

Here, we report the synthesis of a bimetallic supramolecular polymer (SMP) for fabricating an electrochemical nitrite sensor and study the reaction mechanism of the selective oxidation of nitrite b...

An improved and facile aerosol-assisted chemical vapor deposition (AACVD) process for the production of palladium thin film on indium tin oxide (PdNP-ITO) electrodes was described and applied for the electrochemical detection of hydrogen peroxide (H2O2). The detailed characterization of the films by X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS) analysis proved the high crystallinity and phase purity of the nanosized metallic palladium films without the evolution of any elemental impurities from the precursor compound. The as-prepared electrodes were used for nonenzymatic amperometric H2O2 detection via electrochemical reduction. The LOD was 40.8 nM with a high sensitivity of 760.84 μA/(μM cm2). From the experimental scan rate variation analysis, the reduction of H2O2 on the PdNP-ITO electrode surface was determined to be adsorption controlled. For this process of adsorption, we calculated the number of elect...

The high surface-to-volume ratio and desirable chemical, thermal, and catalytic properties of nanomaterials have made them promising electrode materials for sensing applications. As such, different nanomaterials and their nanocomposite-based individual and/or simultaneous detection of dihydroxybenzene (DHB) have been reported in recent years. Due to the low degradation rate and high toxicity of DHB isomers, the development of innovative and robust sensors for their simultaneous detection has received considerable attention. In this review, applications of different nanomaterials (with the exception of carbon nanotubes, graphene, and their derivatives) for individual and/or simultaneous detection of DHB are briefly discussed. The focal point is on the characteristic features of the modified electrodes that improve their electrocatalytic activities toward DHB. Real sample analysis and electrolyte media are also summarized. This review includes studies published from 2011 to 2020.

Dihydroxybenzene is regarded as a serious environmental pollutant. Its detection through electrochemical methods is still challenging due to having a similar structure and overlapping signals with the conventional bare electrode. Thanks to the unique features and wide applicability of carbon nanotubes, graphene, and their derivatives, they can be used as modifiers to overcome the poor resolution ability of bare electrodes in the detection of dihydroxybenzene. This review focuses on the use of carbon nanotubes, graphene, and their derivatives and nanocomposites to enhance the electrocatalytic activity of conventional bare electrodes for dihydroxybenzene sensing. The reports from 2011-2020 on the simultaneous and/or individual detection of three different dihydroxybenzenes - hydroquinone, catechol, and resorcinol - are summarized. This review also highlights the challenges and prospects surrounding the sensitive and selective detection of dihydroxybenzene.

Natural carrier systems existing in mammals have driven current researches to focus in designing new drug carriers with the aid of bionanotechnology. These natural carriers function by mimicking the various physiological entities to safely deliver drug to the intended sites. In this chapter, we have discussed about the development of microorganism and protein/peptide inspired and mimicking drug delivery system. These micro/nanocarriers are capable of targeting specific cells for efficient drug delivery. We have categorized the microorganisms as virus, bacteria, and fungus which have been extensively used for designing drug carriers. The functions and effectiveness of the individual microorganism are explained depending on their way camouflaging the therapeutic molecules. In addition, we have discussed about different protein macromolecules and peptide sequence coated drug nanoparticles that have been used for effective delivery system.

Aiming at constructing a new nonenzymatic electrochemical nitrite sensor, we have prepared a screen-printed fluorine-doped tin oxide (FTO) electrode with activated jute carbon paste (AJCP) (AJCP-SP-FTO) synthesized from jute (Corchorus genus) sticks by using ZnCl2 as activating agent and subsequent carbonizing at 850 °C. Surface morphology, textural properties, chemical composition and nature of pores of AJC were studied by FE-SEM, XRD, EDS, Raman spectroscopy and BET analysis. The surface area of the AJC was found to be 1452.4 m2/g with an average pore diameter of 2.6 nm obtained from a BJH pore-size distribution curve. Electron transfer capacity at the interface of the AJCP material screen-printed FTO was studied by cyclic voltammetry (CV) and EIS techniques. The AJCP-SP-FTO sensor was used for amperometric detection of nitrite. The limit of detection (LOD) for nitrite oxidation was found to be 437 nM for the proposed sensor. The sensitivity of AJCP-SP-FTO toward nitrite was 863.71 μA mM−1 cm−2. From the analysis of electrochemical data, the effective surface area of the AJCP-SP-FTO was 0.12 cm2. We proposed a mechanism for sensitive detection of nitrite based on analysis of experimental findings of spectroscopic and electroanalytical techniques. We further utilized the proposed sensor for analyzing nitrite in tap water. The AJCP-SP-FTO electrode showed good reproducibility and stability.

Nanobiotechnology has grown rapidly and become an integral part of modern disease diagnosis and treatment. Biosynthesized silver nanoparticles (AgNPs) are a class of eco-friendly, cost-effective and biocompatible agents that have attracted attention for their possible biomedical and bioengineering applications. Like many other inorganic and organic nanoparticles, such as AuNPs, iron oxide and quantum dots, AgNPs have also been widely studied as components of advanced anticancer agents in order to better manage cancer in the clinic. AgNPs are typically produced by the action of reducing reagents on silver ions. In addition to numerous laboratory-based methods for reduction of silver ions, living organisms and natural products can be effective and superior source for synthesis of AgNPs precursors. Currently, plants, bacteria and fungi can afford biogenic AgNPs precursors with diverse geometries and surface properties. In this review, we summarized the recent progress and achievements in biogenic AgNPs synthesis and their potential uses as anticancer agents.

An electrochemical sensor based on a cobalt oxide nanorod (Co3O4NR) modified glassy carbon electrode (GCE) (Co3O4NR-GCE) was prepared for simultaneous and selective determination of hydroquinone (HQ) and catechol (CT). Surface morphology and crystallinity of Co3O4NR were investigated employing field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis. The structure (16 nm) of the Co3O4 nanorod was observed in the FESEM image. A sharp peak pattern in the XRD survey revealed the following crystal planes in Co3O4NR material: (111), (220), (311), (222), (400), (422), (511), and (440). Electrochemical characterization of modified Co3O4NR-GCE was carried out performing cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Selective and simultaneous detection of HQ and CT was carried out by performing CV and differential pulse voltammetry (DPV) analysis. In both studies, modified Co3O4NR-GCE showed well defined oxidation and reduction peaks for HQ and CT with enhanced peak current, and the oxidation peaks for HQ and CT were observed at 0.152 V and 0.254 V, respectively, in the CV analysis. Scan rate and pH variation analysis were performed to evaluate different kinetic parameters, including charge transfer coefficient (α = 0.56 for HQ and 0.66 for CT), heterogeneous charge transfer rate constant (ks = 56 for HQ and 72 for CT), and the number of electrons involved in HQ and CT oxidation. Quantitative analysis of HQ and CT was studied by observing the current response of DPV analysis with respect to concentration variation. Here, the detection limit was calculated as 0.2 µM for HQ with a linear concentration range of 5–200 µM, and 0.4 µM for CT with a linear concentration range of 5–150 µM. The practical applicability of the proposed sensor was investigated using sample solutions prepared in tap water. The reported sensor showed impressive selectivity towards HQ and CT in the presence of common interferents.

A highly selective and sensitive electrochemical method was developed for the detection of dopamine (DA), based on a gold nanoparticle (AuNP)-coated taro carbon (TC)-modified glassy carbon electrode (AuNP-TC/GCE). This novel AuNP-TC material was simply prepared by carrying out a pyrolysis of a composite material obtained by treatment of an acid-treated taro stem powder with HAuCl4. Transmission electron microscopy (TEM), Raman spectroscopy, field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were employed to characterize the AuNP-TC material. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to characterize the modified electrode. The modified GCE exhibited a well-defined current response only toward the electrochemical oxidation of DA in a mixture solution of ascorbic acid (AA), DA, and uric acid (UA). This designed electrochemical sensor showed a linear response in the concentration range of 0.5 μM to 250 μM DA and a sensing limit (S/N = 3) of 0.25 μM was found. The sensor was also able to successfully detect DA in a dopamine hydrochloride injection (DAI). Moreover, the sensor exhibited excellent stability and reproducibility.

Research on renewable energy is flourishing, as it promises to reduce costs and deliver clean energy for the future. Water oxidation (WO) is one of the most promising and fascinating research fields, offering environmentally friendly renewable fuel sources. However, to make this a reality, efficient WO electrocatalysts (WOEs) have to be prepared from readily available and cost-effective sources. The catalytic activity of WOEs is directly related to their structure and synthesis process. Thus, researchers have focused on preparing Ni and Co (Ni/Co) oxide WOEs through various thermal treatment processes (TTPs) owing to their simplicity, cost effectiveness, and ability to tune the physicochemical properties of the WOEs. In this review, the effect of TTPs on the catalytic activity of Ni/Co oxide-based WOEs were carefully evaluated. To do so the effect of TTPs on the structure-activity relationship (SAR), their advantages and limitations, and how these methods can be properly optimized for preparing Ni/Co oxide WOEs has been discussed based on published reports. Also, the electrochemical techniques and parameters that are most commonly utilized in determining the catalytic activity of WOEs has been discussed along with a general mechanism for WO at the Ni/Co oxide electrocatalysts.

Here, we report fabricating graphene oxide (GO)_GO, GO_reduced graphene oxide (rGO), rGO_rGO, and rGO_GO electrodes through screen printing and study their electronic structure and properties for electrochemical oxidation of bisphenol A (BPA). The electroanalytical techniques used were cyclic voltammetry, Tafel analysis, electrochemical impedance spectroscopy (EIS), and chronoamperometry. The electron transfer mechanism for all the systems were investigated for BPA analyte. Though the research is just in its infancy, analysis of the data obtained so far showed that BPA interacted differently with each of the systems. The BPA oxidation peak current (Ipa) and peak potentials (Epa) for GO_GO, GO_rGO, rGO_rGO, and rGO_GO were determined to be: 1.93 µA @ 0.51 V; 1.47 µA @ 0.5 V; 0.8 µA @ 0.53 V; and 3.6 µA @ 0.5 V; respectively. Tafel slope analysis yielded values of 32.45 mV/dec for GO_GO, 55.4 mV/dec for GO_rGO, 70 mV/dec for rGO_rGO, 90.1 mV/dec for rGO_GO. These different values of Tafel slope indicates that the electron transfer kinetics is different for each of the systems. We intend to thoroughly investigate the interlayer interaction (ILI) process for these four different setups and how they contribute to the electrode/electrolyte interfacial charge transfer process.

Graphene (GP) has been an object of great interest for researchers ever since its isolation from graphite back in 2004. A great many details about the electronic structure and properties of GP has been extensively studied and the knowledge gained has been utilized in fabricating a wide variety of devices. However, to the best of authors knowledge, there has never been a report studying the interlayer interaction (ILI) properties of graphene oxide (GO)/reduced graphene oxide (rGO) composite. Here, we report fabricating GO_GO, GO_rGO, rGO_rGO, and rGO_GO electrodes through screen printing and study their electronic structure and properties through spectroscopic and electroanalytical methods. The electroanalytical techniques used were cyclic voltammetry, Tafel analysis. electrochemical impedance spectroscopy, chronoamperometry, and galvanostatic charging and discharging (GCD). Standard K3[Fe(CN)6] solution of 1 mM concentration was used in investigating the ILI properties. Furthermore, the electrochemical double layer charge storage (EDLC) mechanism for all the systems were investigated through two electrode symmetrical and asymmetrical setups. Though the research is just in its infancy, analysis of the data obtained so far shows the areal capacitance for the symmetric GO_GO, GO_rGO, rGO_rGO, and rGO_GO systems to be 0.74, 3.24, 0.22, and 0.31 mF/cm2, respectively in 1M KCl aqueous solution. For the asymmetrical system the GO_rGO(anode)-GO_GO(cathode) (4.92 mF/cm2) setup showed the highest areal specific capacitance. The operating potential window optimization revealed that GO_rGO and GO_rGO(anode)-GO_GO(cathode) setups could maintain EDLC up to 1V window, while the other setups started showing deviations after 0.7 V window. We intend to thoroughly investigate the ILI process for these four different setups and how they contribute to the EDLC mechanism.

In this work, a conducting polymer and nanometal composite electrocatalyst was prepared for the sensitive detection of bisphenol A (BPA) over a wide concentration window. Polyaniline (PANI) was first prepared from aniline through a chemical method, and gold nanoparticles (AuNPs) were embedded with the prepared PANI via ultrasonication to obtain the PANI_AuNPs electrocatalyst. The morphological, chemical, and electrochemical properties of the electrocatalyst were then determined, and BPA oxidation was investigated with the help of electroanalytical techniques to understand the electron-transfer process occurring at the PANI_AuNPs interface. The results showed that BPA was oxidized through a multistep electron-transfer process without any intermediate chemical step, and the rate-determining step was the second electron-transfer step. The oxidation proceeded as a 2e–/2H+ process with an electron-transfer coefficient of ≈0.69. These results indicate that the PANI and AuNPs work synergistically to promote the electron transfer from BPA. The quantitative analysis gave a broad linear range and a low limit of detection of 0.4 nM. The sensor was also tested for the detection of BPA in tap water, bottled water, and a canned beverage for real sample analysis.

A non-enzymatic impedimetric glucose sensor was fabricated based on the adsorption of gold nanoparticles (GNPs) onto conductive polyaniline (PANI)-modified glassy carbon electrode (GCE). The modified electrode (GCE/PANI/GNPs) was characterized by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The determination of glucose concentration was based on the measurement of EIS with the mediation of electron transfer by ferricyanide ([Fe(CN)6]3−). The [Fe(CN)6]3− is reduced to ferrocyanide ([Fe(CN)6]4−), which in turn is oxidized at GCE/PANI/GNPs. An increase in the glucose concentration results in an increase in the diffusion current density of the [Fe(CN)6]4− oxidation, which corresponds to a decrease in the faradaic charge transfer resistance (R ct). A wide linear concentration range from 0.3 to 10 mM with a lower detection limit of 0.1 mM for glucose was obtained. The proposed sensor shows high sensitivity, good reproducibility, and stability. In addition, the sensor exhibits no interference from common interfering substances such as ascorbic acid, acetaminophen, and uric acid.

Here, we report a porous carbon material derived from coal of Boropukuria, Dinajpur, Bangladesh that has been used for fabricating high-power supercapacitor. The activated coal carbon nanosheets (ACCNs), prepared using simple pyrolysis, had a high yield (60%), and contained O and N heteroatoms, along with a hierarchical porous network of micro, meso, and macro pores. Surface morphology, elemental composition, crystallite size, and porous network of the ACCNs have been studied using FESEM, XPS, Raman, and N2 adsorption-desorption analysis. An operating potential window of 1.1 V was obtained in 1 M KCl neutral electrolyte solution. At 2.25 A/g the calculated specific energy was ~ 39.04 Wh/kg, along with a high specific power of ~ 1237.5 W/kg. The ACCNs material was able to retain specific energy of ~ 22.92 Wh/kg and specific power of ~ 41,250 W/kg at a high current density of 75 A/g. The contribution of capacitive (non-Faradic), and diffusion intercalation (Faradic) current has been investigated using Cottrell and Dunn's equations. The ACCNs material was used for making a coin cell prototype supercapacitor device and tested with a light emitting diode (LED).

In this article, theoretical and computational (CP) analysis were carried out on the experimental data for the nonenzymatic oxidation of nitrite at the modified electrode to better understand the underlying chemistry. We studied the kinetics of the electron transfer process through various electroanalytical techniques and simulated the cyclic voltammetry (CV) data using Butler-Volmer equation. The CP methods were used for understanding the molecular interaction processes at the electrode-electrolyte interface. The modified electrodes were developed by the electrodeposition of poly (brilliant cresyl blue) (PBCP) on an electrochemically reduced graphene oxide (ERGO) at the activated glassy carbon electrode (AGCE) (AGCE/ERGO/PBCB). The AGCE/ERGO/PBCB sensor was characterized through electrochemical and electron microscopy methods. Analysis of the characterization data supported our assumption, that AGCE is the better platform for the optimal electrochemical reduction of GO compared to the GCE for the purpose of the electropolymerization process. Simulated CV showed that the oxidation process followed a 2e− transfer pathway, but the electron transfer took place in a step wise manner. While, CP data revealed that the AGCE, ERGO, and PBCB interacted with each other through the parallel-displaced and sandwich types π – π stacking, and electrostatic interactions. H⋯O–H, and H⋯N–H hydrogen bonds between the functional groups of AGCE, and ERGO also promoted the electron transfer process. The AGCE/ERGO/PBCB was then used for the nonenzymatic detection of the nitrite species in the acidic medium using amperometric and CV techniques. The sensor was also tested for real sample analysis.

Graphene (GP)-based materials have been used extensively in the fabrication of highly sensitive electrochemical sensors (ECSs) due to their unique and excellent physical and electric properties. The application of GP-based materials for the electrochemical detection of biomolecules is extremely vital to the development of biomedical instruments, clinical diagnosis, and disease treatment. In this chapter, we mainly focused on biomedical applications, importance, and mechanism of GP-based ECSs. Electronic properties of GP materials that are responsible for their outstanding biomolecule sensing ability were briefly discussed. We have also explored the history and different types of GP-type materials along with their properties and application in fabricating ECSs. In order to achieve a better understanding of the influence of GP and their derivatives in developing superior ECSs, we have discussed general reaction mechanisms for several biologically important analytes. A table was also provided with ample references summarizing the recent developments and applications of GP materials in fabricating ECSs. Finally, a brief conclusion was drawn as to how the GP and their derivatives may influence the future of the biomedical application of ECSs.