Ferrite Nanocomposite Based Electrochemical Sensor: Characterization, Voltammetric and Amperometric Studies for Electrocatalytic Detection of Formaldehyde in Aqueous Media

Recent Advances in Electrochemical Sensors for Formaldehyde

Formaldehyde, a ubiquitous indoor air pollutant, plays a significant role in various biological processes, posing both environmental and health challenges. This comprehensive review delves into the latest advancements in electrochemical methods for detecting formaldehyde, a compound of growing concern due to its widespread use and potential health hazards. This review underscores the inherent advantages of electrochemical techniques, such as high sensitivity, selectivity, and capability for real-time analysis, making them highly effective for formaldehyde monitoring. We explore the fundamental principles, mechanisms, and diverse methodologies employed in electrochemical formaldehyde detection, highlighting the role of innovative sensing materials and electrodes. Special attention is given to recent developments in nanotechnology and sensor design, which significantly enhance the sensitivity and selectivity of these detection systems. Moreover, this review identifies current challenges and discusses future research directions. Our aim is to encourage ongoing research and innovation in this field, ultimately leading to the development of advanced, practical solutions for formaldehyde detection in various environmental and biological contexts.

Efficient formaldehyde sensor based on PtPd nanoparticles-loaded nafion-modified electrodes

The noble metal-based electrochemical sensor design for efficient and stable formaldehyde(FA) detection is important ongoing research. In this paper, PtPd/Nafion/GCE is prepared by electrochemical cyclic voltammetry deposition method based on electrodepositing nanostructured platinum (Pt)-palladium (Pd) nanoparticles in Nafion film-coated glassy carbon electrode (GCE). The influence of deposition parameters and chemical composition (atomic ratio of Pt and Pd) on the electrochemical behaviour of PtPd/Nafion/GCE has been investigated. PtPd/Nafion/GCE displays a remarked electrocatalytic activity for the oxidation of FA and exhibits a linear relationship in the range of 10-5000μM, with a detection limit of 3.3μM in 0.1 M H2SO4solution. It is proved that the detection performance of PtPd/Nafion/GCE electrode is valuable for further application with low detection limit, wide linear range, favourable selectivity and high response.

Highly Active Palladium-Decorated Reduced Graphene Oxides for Heterogeneous Catalysis and Electrocatalysis: Hydrogen Production from Formaldehyde and Electrochemical Formaldehyde Detection

The exploitation of highly efficient and stable hydrogen generation from chemical storage of formaldehyde (FA) is of great significance to the sustainable development of the future. Moreover, developing an accurate, rapid, reliable, and cost-effective catalyst for electrochemical detection of FA in solution is appealing. Herein, we report rational construction of Pd nanoparticles decorated reduced graphene oxides (Pd/rGO) nanohybrids not only as robust catalysts to produce hydrogen from alkaline FA solution and but also electrocatalysts for electrochemical detection of FA. By optimizing the reaction parameters including FA concentration, NaOH concentration and reaction temperature, Pd/rGO with Pd loading of 0.5 wt% could exhibit a high hydrogen production rate of 272 mL g^-1min^-1 at room temperature of 25 °C, which is 3.2 times that of conventional Pd NPs. In addition, as-prepared Pd/rGO nanohybrids modified glassy carbon (GC) electrodes are used as FA-detected electrochemical sensors. A sensitive oxidation peak with a current density of 8.38 mA/cm² was observed at 0.12 V (vs. Ag/AgCl) in 0.5 M NaOH containing 10 mM FA over Pd/rGO catalysts with Pd loading of 0.5 wt%. The results showed the prepared Pd/rGO nanocatalyst not only exhibited efficient and stable hydrogen production from alkaline FA solution but also had good electrocatalytic properties with respect to formaldehyde electrooxidation as a result of the synergistic effect of Pd NPs and rGO nanosheets.

Exploring multifunctional behaviour of g-C3N4 decorated BiVO4/Ag2CO3 hierarchical nanocomposite for simultaneous electrochemical detection of two nitroaromatic compounds and water splitting applications

Development of multifunctional ternary nanocomposite based electrocatalysts for detection of toxic elements and generation of renewable energy describes an environmentally sustainable technique to address the dual challenges of pollution and energy. Herein, we adopted microwave-assisted synthesis to design a multifunctional graphitic carbon nitride (g-C₃N₄) decorated BiVO₄/Ag₂CO₃ (BVG@C) hierarchical ternary nanocomposite for sensing and water splitting applications. The morphological, structural and elemental characterizations demonstrate the successful decoration of carbon nitride on the composite surface. The electrochemical activity of BVG@C modified glassy carbon electrode reveals excellent redox behaviour towards simultaneous detection of 4-Nitrophenol (4-NP) and 4-Nitroaniline (PNA). The modified electrode shows rapid amperometric current response with high sensitivity of 2.368 μA mM cm^-2 and 1.534 mA mM cm^-2 and low detection limit of 0.012 μmol L^-1and 0.028 μmol L^-1, respectively for 4-NP and PNA. Moreover, the modified electrode was further investigated for hydrogen evolution and oxygen evolution reactions and the electrocatalytic results show admirable activity and good stability for oxygen evolution with very low overpotential of 136 mV in alkaline medium. It is worthwhile to mention that the excellent activity of electrocatalyst can be ascribed to the decoration and electronic interaction of g-C₃N₄ with the BiVO₄/Ag₂CO₃ nanocomposite, increasing its surface area, active sites, charge transfer and decreasing resistance.

Optical, electrochemical and photocatalytic properties of cobalt doped CsPbCl3 nanostructures: a one-pot synthesis approach

The present manuscript aims at the synthesis of cesium based halide perovskite nanostructures and the effect of cobalt doping on the structural, optical, lumnisent, charge storage and photocatalytic properties. In a very first attempt, we report the solvothermal synthesis of Co doped CsPbCl₃ nanostructures under subcritical conditions. The structural features were demonstrated by X-ray diffraction (XRD) Surface morphology determined cubic shape of the synthesized particles. Doping is an excellent way to modify the properties of host material in particular to the electronic structure or optical properties. Incorporation of Co²⁺ ions in the perovskite structure tunes the optical properties of the nanostructures making this perovskite a visible light active material (Eg = 1.6 eV). This modification in the optical behaviour is the result of size effect, the crystallite size of the doped nanostructures increases with cobalt doping concentration. Photolumniscance (PL) study indicated that CsPbCl₃ exhibited Blue emission. Thermogravametric analysis (TGA) revealed that the nanostructures are quite stable at elavated temperatures. The electrochemical performance depicts the pseudocapacative nature of the synthesized nanostructures and can used for charge storage devices. The charge storage capability showed direct proportionality with cobalt ion concentration. And Finally the photocatalytic performance of synthesized material shows superior catalytic ability degrading 90% of methylene blue (MB) dye in 180 min under visible light conditions.

Nanoremediation technologies for sustainable remediation of contaminated environments: Recent advances and challenges

A major and growing concern within society is the lack of innovative and effective solutions to mitigate the challenge of environmental pollution. Uncontrolled release of pollutants into the environment as a result of urbanisation and industrialisation is a staggering problem of global concern. Although, the eco-toxicity of nanotechnology is still an issue of debate, however, nanoremediation is a promising emerging technology to tackle environmental contamination, especially dealing with recalcitrant contaminants. Nanoremediation represents an innovative approach for safe and sustainable remediation of persistent organic compounds such as pesticides, chlorinated solvents, brominated or halogenated chemicals, perfluoroalkyl and polyfluoroalkyl substances (PFAS), and heavy metals. This comprehensive review article provides a critical outlook on the recent advances and future perspectives of nanoremediation technologies such as photocatalysis, nano-sensing etc., applied for environmental decontamination. Moreover, sustainability assessment of nanoremediation technologies was taken into consideration for tackling legacy contamination with special focus on health and environmental impacts. The review further outlines the ecological implications of nanotechnology and provides consensus recommendations on the use of nanotechnology for a better present and sustainable future.

A "signal off" aptasensor based on NiFe2O4 NTs and Au@Pt NRs for the detection of deoxynivalenol via voltammetry

A "signal off" aptasensor has been developed to detect deoxynivalenol (DON). DON aptamers (Apt) were used as biological recognition elements, nickel ferrite nanotubes (NiFe₂O₄ NTs) are used as the base material to increase the surface area of the electrode, and the Au@Pt NRs were used as carriers for loading signal labels thionine (Thi) and complementary strand (cDNA). In the presence of DON it will be specifically captured by Apt, then the competition mechanism was triggered; the signal molecules fall off from the electrode surface, which then causes the electrode signal to decrease. NiFe₂O₄ NTs and Au@Pt NRs were characterized by transmission electron microscope (TEM), scanning electron micrograph (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The designed sensor provides a concentration range of 1 × 10^-8 to 5 × 10^-4 mg mL^-1 and limit of detection of 3.02 × 10^-9 mg mL^-1. Determination of DON in corn meal samples was investigated and the recovery was 98.4 to 103.5%. The proposed aptasensor displayed good sensitivity, high specificity, and acceptable reproducibility. Graphical abstract Based on NiFe₂O₄ NTs as substrate material and Au@Pt NRs as signal label prepared DON aptasensor for the determination of DON.

The non-enzymatic electrochemical detection of glucose and ammonia using ternary biopolymer based-nanocomposites

Novel biopolymer-based nanocomposites exhibit significant electrocatalytic activity towards glucose and aqueous ammonia detection with high sensitivity and low detection limits.

Photocatalytic, anti-bacterial performance and development of 2,4-diaminophenylhydrazine chemical sensor probe based on ternary doped Ag·SrSnO3 nanorods

Ag·SrSnO₃ NRs is an excellent photocatalyst, kills both Gram positive and Gram negative bacteria. The 2,4-DAPHyd sensor fabricated by layered Ag·SrSnO₃ NRs onto GCE shows high sensitivity (7.5854 μA μM⁻¹ cm⁻²); LDR, 0.1 nM~0.01 mM & LOD, 96.13 ± 4.81 pM.