Voltammetric sensing of bisphenol A based on a single-walled carbon nanotubes/poly{3-butyl-1-[3-(N-pyrrolyl)propyl] imidazolium ionic liquid} composite film modified electrode

Properties and Recent Advantages of N,N’-dialkylimidazolium-ion Liquids Application in Electrochemistry

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N,Nʹ-dialkylimidazolium-ion liquids is one of the important ionic liquids with a wide range of application as conductive electrolyte and in electrochemistry. The modified electrodes create a new view in fabrication of electroanalytical sensors. Many modifiers have beeen suggested for modification of electroanalytical sensor since many years ago. Over these years, ionic liquids and especially room temperature ionic liquids have attracted more attention due to their wide range of electrochemical windows and high electrical conductivity. N,Nʹ-dialkylimidazolium-ion liquids are one of the main important ionic liquids suggested for modification of bare electrodes and especially carbon paste electrodes. Although many review articles have reported onthe use of ionic liquids in electrochemical sensors, no review article has been specifically introduced so far on the review of the advantages of N,Nʹ-dialkylimidazolium ionic liquid. Therefore, in this review paper we focused on the introduction of recent advantages of N,Nʹ-dialkyl imidazolium ionic liquid in electrochemistry.

Reaction mechanism of antibiotic bacteria residues as a green reductant for highly efficient recycling of spent lithium-ion batteries

In this study, antibiotic bacteria residues (ABRs) is proposed as a novel green reducing agent and it is found that the reducing agent can realize the efficient recovery of the valuable metals in spent cathode powder (SCP), reduce the environmental pollution and realize the high-value utilization of the biomass waste. The leaching efficiency of Ni, Co, Mn and Li can reach 99.57%, 98.50%, 98.99% and 99.90% respectively under the optimal conditions of 3 mol L^-1 H₂SO₄, mass ratio of ABRs to SCP of 0.8:1, liquid/solid ratio of 30:1 mL g^-1, the temperature of 363 K and time of 2.5 h. Leaching kinetics results shows that the reaction process is controlled by the chemical reaction with apparent activation energy exceeding than 40 kJ/mol. More importantly, the detailed ABRs leaching mechanism is proposed that the metabolite of CaC₂O₄ and reducing sugar in ABRs provide a synergistic reduction effect on the recovery of valuable metals. Furthermore, acid leaching residue can be regenerated to obtain lithium-ion anode materials with excellent electrochemical properties. The entire process is a sustainable green recycling strategy by using waste ABRs waste to treat spent lithium-ion batteries (LIBs), recovering valuable metals efficiently and minimizing environmental pollution.

A Review of Nanocomposite-Modified Electrochemical Sensors for Water Quality Monitoring

Electrochemical sensors play a significant role in detecting chemical ions, molecules, and pathogens in water and other applications. These sensors are sensitive, portable, fast, inexpensive, and suitable for online and in-situ measurements compared to other methods. They can provide the detection for any compound that can undergo certain transformations within a potential window. It enables applications in multiple ion detection, mainly since these sensors are primarily non-specific. In this paper, we provide a survey of electrochemical sensors for the detection of water contaminants, i.e., pesticides, nitrate, nitrite, phosphorus, water hardeners, disinfectant, and other emergent contaminants (phenol, estrogen, gallic acid etc.). We focus on the influence of surface modification of the working electrodes by carbon nanomaterials, metallic nanostructures, imprinted polymers and evaluate the corresponding sensing performance. Especially for pesticides, which are challenging and need special care, we highlight biosensors, such as enzymatic sensors, immunobiosensor, aptasensors, and biomimetic sensors. We discuss the sensors' overall performance, especially concerning real-sample performance and the capability for actual field application.

Recent Advances in Electrochemical Sensors and Biosensors for Detecting Bisphenol A

In recent years, several studies have focused on environmental pollutants. Bisphenol A (BPA) is one prominent industrial raw material, and its extensive utilization and release into the environment constitute an environmental hazard. BPA is considered as to be an endocrine disruptor which mimics hormones, and has a direct relationship to the development and growth of animal and human reproductive systems. Moreover, intensive exposure to the compound is related to prostate and breast cancer, infertility, obesity, and diabetes. Hence, accurate and reliable determination techniques are crucial for preventing human exposure to BPA. Experts in the field have published general electrochemical procedures for detecting BPA. The present timely review critically evaluates diverse chemically modified electrodes using various substances that have been reported in numerous studies in the recent decade for use in electrochemical sensors and biosensors to detect BPA. Additionally, the essential contributions of these substances for the design of electrochemical sensors are presented. It has been predicted that chemically modified electrode-based sensing systems will be possible options for the monitoring of detrimental pollutants.

Advances in sensing and biosensing of bisphenols: A review

Bisphenols (BPs) are well known endocrine disrupting chemicals (EDCs) that cause adverse effects on the environment, biotic life and human health. BPs have been studied extensively because of an increasing concern for the safety of the environment and for human health. They are major raw materials for manufacturing polycarbonates, thermal papers and epoxy resins and are considered hazardous environmental contaminants. A vast array of sensors and biosensors have been developed for the sensitive screening of BPs based on carbon nanomaterials (carbon nanotubes, fullerenes, graphene and graphene oxide), quantum dots, metal and metal oxide nanocomposites, polymer nanocomposites, metal organic frameworks, ionic liquids and molecularly imprinted polymers. This review is devoted mainly to a variety of sensitive, selective and reliable sensing and biosensing methods for the detection of BPs using electrochemistry, fluorescence, colorimetry, surface plasmon resonance, luminescence, ELISAs, circular dichroism, resonance Rayleigh scattering and adsorption techniques in plastic products, food samples, food packaging, industrial wastes, pharmaceutical products, human body fluids and many other matrices. It summarizes the advances in sensing and biosensing methods for the detection of BPs since 2010. Furthermore, the article discusses challenges and future perspectives in the development of novel sensing methods for the detection of BP analogs.

A novel ionic liquid functionalized graphene oxide supported gold nanoparticle composite film for sensitive electrochemical detection of dopamine

A simple and sensitive electrochemical sensor for detection of dopamine has been developed based on ionic liquid functionalized graphene oxide supported gold nanoparticles (GO-IL-AuNPs) coated onto a glassy carbon electrode.

Ultra-sensitive determination of epinephrine based on TiO2-Au nanoclusters supported on reduced graphene oxide and carbon nanotube hybrid nanocomposites

A highly efficient and sensitive electrochemical sensor for EP based on reduced graphene and multi-walled carbon nanotube hybrid nanocomposites loaded TiO2-Au nano-clusters modified glassy carbon electrode was developed. The surface nature and morphology of the nanocomposite film and the electrochemical properties of the sensor were characterized by Raman spectra, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectra (EDX), Fourier transform infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. Carbon nanomaterials were widely used in sensing due to its large electroactive surface area, fast electron transport and strong adsorption capacity. Meanwhile, TiO2-Au nano-clusters could accelerate the electron transfer, increase reactive site and extend electrochemical response window. The nanocomposite film could greatly enhance the response sensitivity and decrease the overpotential. The resulting sensor showed an excellent electrocatalytic activity toward EP. Under the optimum conditions (i.e. pH6.0, 0.1M PBS, preconcentration for 110s), Differential pulse voltammetry was employed to detect ultra-trace amounts of EP. The result of a wide linear range of 1.0-300nM and limited of detection 0.34nM (S/N=3) were obtained. The constructed sensor exhibited excellent accuracy and precision, the relative standard deviation (RSD) was less than 5%. The nanocomposite film sensor was successfully used to accurately detect the content of EP in practical samples, and the recoveries for the standards added are 97%-105%.

Sensitive Adsorptive Voltammetric Method for Determination of Bisphenol A by Gold Nanoparticle/Polyvinylpyrrolidone-Modified Pencil Graphite Electrode

A novel electrochemical sensor gold nanoparticle (AuNP)/polyvinylpyrrolidone (PVP) modified pencil graphite electrode (PGE) was developed for the ultrasensitive determination of Bisphenol A (BPA). The gold nanoparticles were electrodeposited by constant potential electrolysis and PVP was attached by passive adsorption onto the electrode surface. The electrode surfaces were characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The parameters that affected the experimental conditions were researched and optimized. The AuNP/PVP/PGE sensor provided high sensitivity and selectivity for BPA recognition by using square wave adsorptive stripping voltammetry (SWAdSV). Under optimized conditions, the detection limit was found to be 1.0 nM. This new sensor system offered the advantages of simple fabrication which aided the expeditious replication, low cost, fast response, high sensitivity and low background current for BPA. This new sensor system was successfully tested for the detection of the amount of BPA in bottled drinking water with high reliability.

Voltammetric determination of hexestrol based on the enhanced effect of a polymerized 3-decyl-1-(3-pyrrole-propyl)imidazolium tetrafluoroborate ionic liquid film electrode

3-Decyl-1-(3-pyrrole-propyl)imidazolium tetrafluoroborate (DPIMBF4) ionic liquid was synthesized and characterized. DPIMBF4 ionic liquid not only possesses a pyrrole group that can be electrochemically polymerized onto a glassy carbon electrode surface by using a multipotential step technique, but it also contains a long carbon chain that can improve the stability of a polymerized ionic liquid film in an aqueous solution. X-ray photoelectron spectroscopy, scanning electron microscope, and electrochemical impedance spectroscopy were used to confirm the successful polymerization of the ionic liquid. Voltammetry was employed to investigate the electrochemical behaviors of an environmental estrogen, hexestrol, at the polymerized ionic liquid film electrode. Hexestrol presents an irreversible oxidation peak at the polymerized DPIMBF4 ionic liquid film electrode. Compared with the bare glassy carbon electrode, the oxidation peak of hexestrol increased significantly on the polymerized DPIMBF4 ionic liquid film electrode. The oxidation peak current was found to be linearly related to hexestrol concentration in the range of 5.0 × 10−9 to 1.0 × 10−5 mol L−1. The detection limit was calculated to be 1.25 × 10−9 mol L−1 (S/N = 3). Hexestrol in crucian meat was determined using the polymerized DPIMBF4 ionic liquid film electrode with good accuracy.

AuNp@MOF composite as electrochemical material for determination of bisphenol A and its oxidation behavior study

A hybrid material on the carbon paste electrode exhibited a greater electroactivity for the determination of an endocrine disruptor.

Electrochemical sensing of bisphenol A by graphene-1-butyl-3-methylimidazolium hexafluorophosphate modified electrode

Simple and low cost sensor for the determination of bisphenol A (BPA) based on graphene-1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6) modified glassy carbon electrode was developed. It was an irreversible oxidation process of BPA on the modified electrode. Experimental conditions such as modified volume, pH, scan rate and accumulation time have been optimized. The modified electrode provided a considerable enhancement of BPA oxidation. The electrochemical response of BPA on this modified electrode was better than those on the graphene modified electrode and bare electrode. The detection limit of BPA was 8nM (S/N=3), the linear range was from 20nM to 2µM. The modified electrode has been employed for determination of milk and soda spiked BPA successfully.

Electrochemical fabrication of polymerized imidazole-based ionic liquid bearing pyrrole moiety for sensitive determination of hexestrol in chicken meat

1-[3-(tert-Butoxycarbonylamino)propyl]-3-[3-(N-pyrrole)propyl]imidazolium tetrafluoroborate [(t-Boc-APPPI)BF4], which is a novel pyrrolyl-functionalized ionic liquid, was synthesized and characterized. Subsequently, it was electrochemically deposited onto a glassy carbon electrode surface to fabricate a polymerized ionic liquid film electrode. X-ray photoelectron spectroscopy, scanning electron microscope and electrochemical impedance spectroscopy were used to confirm the successful polymerization of ionic liquid. Voltammetric behaviors of hexestrol at the film electrode were investigated. The oxidation peak slightly shifted towards positive potential, however, dramatically increased in peak current. Experimental conditions for hexestrol determination were optimized. The oxidation peak current is linear with hexestrol concentration in the range of 1.0 × 10(-8)-1.0 × 10(-5) mol L(-1). The detection limit is estimated to be 2.1 × 10(-9) mol L(-1) (S/N=3). Hexestrol in chicken meat was determined using the film electrode with good accuracy.

A reusable evanescent wave immunosensor for highly sensitive detection of bisphenol A in water samples

This paper proposed a compact and portable planar waveguide evanescent wave immunosensor (EWI) for highly sensitive detection of BPA. The incident light is coupled into the planar waveguide chip via a beveled angle through undergoing total internal reflection, where the evanescent wave field forms and excites the binding fluorophore-tagged antibodies on the chip surface. Typical calibration curves obtained for BPA has detection limits of 0.03 μg/L. Linear response for BPA ranged from 0.124 μg/L-9.60 μg/L with 50% inhibition concentration for BPA of 1.09 ± 0.25 μg/L. The regeneration of the planar optical waveguide chip allows the performance of more than 300 assay cycles within an analysis time of about 20 min for each assay cycle. By application of effective pretreatment procedure, the recoveries of BPA in real water samples gave values from 88.3% ± 8.5% to 103.7% ± 3.5%, confirming its application potential in the measurement of BPA in reality.