GO composite encompassing a tetraruthenated cobalt porphyrin-Ni coordination polymer and its behavior as isoniazid BIA sensor

A Tröger's base-linked aluminium phthalocyanine polymer for discriminative electrochemical sensing of the antibiotic isoniazid

Isoniazid is a first-line drug used to treat tuberculosis. However, its excessive use can lead to serious adverse effects. Thus, strict monitoring of the isoniazid levels in medications and human systems is required. In this study, a new polymer (AlPc-TB POP) containing a metal phthalocyanine and Tröger's base was synthesized and explored as an electrocatalyst for the oxidation of isoniazid. The results indicated that the polymer is an excellent electron-transfer medium for isoniazid oxidation. The AlPc-TB POP-based sensor quantified isoniazid in the linear range of 0.1-130 μM, with a detection limit of 0.0185 μM. The response of the developed sensor to isoniazid was reproducible and stable. Furthermore, this method can accurately determine isoniazid levels by ignoring the influence of common interfering species in tablets and biological samples. This study contributes to the development of nitrogen-rich porous organic polymers and offers a novel strategy for addressing challenges in disease therapeutic efficacy and public safety monitoring.

A highly sensitive and ecofriendly assay platform for the simultaneous electrochemical determination of rifampicin and isoniazid in human serum and pharmaceutical formulations

Simple fabrication of an electrochemical sensor for simultaneous determination of rifampicin and isoniazid based on electrochemical modification of SPCE surface with reduced graphene oxide and nickel hydroxide film (Ni(OH)2/rGO/SPCE) without using toxic chemical agents.

Fabrication of a Tubular CuO/NiO Biomimetic Nanozyme with Synergistically Promoted Peroxidase-like Performance for Isoniazid Sensing

Isoniazid is an antibiotic primarily used in clinical treatment of tuberculosis, but excessive usage can lead to serious consequences such as hepatotoxicity, neurotoxicity, and even coma and death. Therefore, it is critical to exploit a quick, facile, and acute way for isoniazid analysis. In this work, we have demonstrated an efficient electrospinning-carbonation-wet chemistry reaction-calcination process to fabricate CuO/NiO nanotubes (NTs) as a promising nanozyme for peroxidase (POD) mimicking. In virtue of the distinct tubular structure and synergy between CuO and NiO from the mechanisms of both electron transfer and hydroxyl radical generation, a remarkably improved catalytic activity is realized for the CuO/NiO NTs compared with bare CuO and NiO samples. According to the admirable POD-like property, a rapid colorimetric detection for isoniazid is accomplished with a detection limit of 0.4 μM (S/N = 3) and favorable selectivity. In addition, the sensing capability of isoniazid in a real sample is also investigated with satisfactory results. This work offers a novel tactic to fabricate high-performance nanozymes with efficient isoniazid sensing capabilities to address challenges in disease treatment efficacy and public safety monitoring.

Cascade amplification strategy combined with analyte-triggered fluorescence switching of dual-quenching system for highly sensitive detection of isoniazide

A sensitive fluorescence sensing platform consisting of manganese dioxide nanosheets (MnO₂) and gold nanoparticles (AuNPs) as dual nanoquenchers has been constructed to detect isoniazid combined with analyte-triggered cascade reactions. The fluorescence of 2,3-diaminophenazine (DAP) is quenched simultaneously by MnO₂ and AuNPs via inner filter effect. MnO₂ is decomposed by isoniazid to generate Mn²⁺, which makes AuNPs aggregated. The quenching abilities of both the decomposed MnO₂ and aggregated AuNPs are inhibited, causing remarkable fluorescence recovery. The usage of dual nanoquenchers enhances the quenching efficiency and reduces the fluorescence background. Moreover, the isoniazid-triggered cascade reaction further amplifies the readout signal. Thus, this strategy exhibits higher sensitivity towards the detection of isoniazid. Compared with MnO₂-based fluorescence assay, this strategy possesses lower limit of detection. This strategy has been successfully used to detect isoniazid in pharmaceutical preparations, which is of great significance for drug analysis.

A New Supramolecular Tetraruthenated Cobalt (II) Porphyrazine Displaying Outstanding Electrocatalytical Performance in Oxygen Evolution Reaction

A new supramolecular electrocatalyst for Oxygen Evolution Reaction (OER) was synthesized from a central multibridging cobalt tetrapyridylporphyrazine (CoTPyPz) species by attaching four [Ru(bpy)₂Cl]⁺ groups. Both CoTPyPz and the tetraruthenated cobalt porphyrazine species, TRuCoTPyPz, form very homogenous molecular films just by dropcasting their methanol solutions onto GCE electrodes. Such films exhibited low overpotentials for O₂ evolution, e.g., 560 e 340 mV, respectively, displaying high stability, typically exceeding 15 h. The kinetic parameters obtained from the Tafel plots showed that the peripheral complexes are very important for the electrocatalytic activity. Hyperspectral Raman images taken along the electrochemical process demonstrated that the cobalt center is the primary active catalyst site, but its performance is enhanced by the ruthenium complexes, which act as electron-donating groups, in the supramolecular system.

Sensor-Embedded Face Masks for Detection of Volatiles in Breath: A Proof of Concept Study

The correlation between breath volatilome and health is prompting a growing interest in the development of sensors optimized for breath analysis. On the other hand, the outbreak of COVID-19 evidenced that breath is a vehicle of infection; thus, the introduction of low-cost and disposable devices is becoming urgent for a clinical implementation of breath analysis. In this paper, a proof of concept about the functionalization of face masks is provided. Porphyrin-based sensors are among the most performant devices for breath analysis, but since porphyrins are scarcely conductive, they make use of costly and bulky mass or optical transducers. To overcome this drawback, we introduce here a hybrid material made of conducting polymer and porphyrins. The resulting material can be easily deposited on the internal surface of standard FFP face masks producing resistive sensors that retain the chemical sensitivity of porphyrins implementing their combinatorial selectivity for the identification of volatile compounds and the classification of complex samples. The sensitivity of sensors has been tested with respect to a set of seven volatile compounds representative of diverse chemical families. Sensors react to all compounds but with a different sensitivity pattern. Functionalized face masks have been tested in a proof-of-concept test aimed at identifying changes of breath due to the ingestion of beverages (coffee and wine) and solid food (banana- and mint-flavored candies). Results indicate that sensors can detect volatile compounds against the background of normal breath VOCs, suggesting the possibility to embed sensors in face masks for extensive breath analysis

Functionalization of Graphene Oxide with Porphyrins: Synthetic Routes and Biological Applications

Among the available carbon nanomaterials, graphene oxide (GO) has been widely studied because of the possibility of anchoring different chemical species for a large number of applications, including those requiring water-compatible systems. This Review summarizes the state-of-the-art of synthetic routes used to functionalize GO, such as those involving multiple covalent and non-covalent bonds to organic molecules, functionalization with nanoparticles and doping. As a recent development in this field, special focus is given to the formation of nanocomposites comprising GO and porphyrins, and their characterization through spectroscopic techniques (such as UV-Vis, fluorescence, Raman spectroscopy), among others. The potential of such hybrid systems in targeted biological applications is also discussed, namely for cancer therapies relying on photodynamic and photothermal therapies and for the inhibition of telomerase enzyme. Lastly, some promising alternative materials to GO are presented to overcome current challenges of GO-based research and to inspire future research directions in this field.

Catalytic properties of supramolecular polymetallated porphyrins

Supramolecular polymetallated pyridylporphyrins have been specially designed for exploring the binding and synergism between the macrocyclic system and the peripheral metal complexes. Their chemistry has been reviewed, focusing on the outstanding behavior in solution or as thin organized films generated with several nanomaterials, for application as molecular devices and in energy conversion processes.

Recent Advances in Chemical Sensors Using Porphyrin-Carbon Nanostructure Hybrid Materials

Porphyrins and carbon nanomaterials are among the most widely investigated and applied compounds, both offering multiple options to modulate their optical, electronic and magnetic properties by easy and well-established synthetic manipulations. Individually, they play a leading role in the development of efficient and robust chemical sensors, where they detect a plethora of analytes of practical relevance. But even more interesting, the merging of the peculiar features of these single components into hybrid nanostructures results in novel materials with amplified sensing properties exploitable in different application fields, covering the areas of health, food, environment and so on. In this contribution, we focused on recent examples reported in literature illustrating the integration of different carbon materials (i.e., graphene, nanotubes and carbon dots) and (metallo)porphyrins in heterostructures exploited in chemical sensors operating in liquid as well as gaseous phase, with particular focus on research performed in the last four years.

Bimetallic cobalt-iron diselenide nanorod modified glassy carbon electrode: an electrochemical sensing platform for the selective detection of isoniazid

The increasing demand of a sensitive and portable electrochemical sensing platform in pharmaceutical analysis has developed widespread interest in preparing electrode materials possessing remarkable properties for the electrochemical determination of target drug analytes. Herein, we report the synthesis, characterization and application of bimetallic cobalt-iron diselenide (FeCoSe₂) nanorods as electrode modifiers for the selective detection of a commonly used anti-tuberculosis drug Isoniazid (INZ). We prepared FeCoSe₂ nanorods by a simple hydrothermal route and characterized these by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and temperature-programmed reduction (TPR) techniques. The electrochemical characterization of FeCoSe₂ modified GCE was performed by cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). Under optimized experimental conditions, a linear current-concentration response was obtained for INZ in the range of 0.03–1.0 μM, with very low limit of detection 1.24 × 10⁻¹⁰ M. The real applicability of the designed FeCoSe₂/GCE sensing platform was adjudicated by the detection of INZ in biological samples.

FeCoSe₂ bimetallic nanorods were synthesized by hydrothermal method. The modified electrode responded excellently towards isoniazid detection with LOD of 1.24 × 10⁻¹⁰ M. FeCoSe₂/GCE showed applicability for INZ detection in real samples.

Recent advances in electroanalytical drug detection by porphyrin/phthalocyanine macrocycles: developments and future perspectives

Porphyrins and phthalocyanines used to construct sensors for electroanalytical drug detection.

Novel ball-milled biochar-vermiculite nanocomposites effectively adsorb aqueous As(Ⅴ)

Ball milling was used to fabricate a nanocomposite of 20% hickory biochar (600 °C) and 80% expanded vermiculite (20%-BC/VE). This novel composite adsorbent had much higher removal of As(V) from aqueous solutions than ball-milled biochar and expanded vermiculite. Characterization of these adsorbents showed that the enhanced As(V) adsorption was ascribed to much larger surface area and pore volume (2-6 times), notable changes in crystallinity, activation of cations, and increased functional groups in the nanocomposite compared with the ball-milled products of their pristine counterparts. The As(V) adsorption process by the 20%-BC/VE fitted well with the pseudo-second-order kinetic model (R2= 0.990) and Langmuir isotherm model (R2= 0.989) with a maximum adsorption capacity of 20.1 mg g-1. The 20%-BC/VE best performed at pH about 6. The adsorption efficiency was not sensitive to the competition of NO3-, Cl-, SO42-, as well as the coexistence of humic acid. However, the adsorption capacity for As(V) was significantly reduced by coexisting with PO43-. The 20%-BC/VE composite can potentially serve as a superior low-cost adsorbent for As(V) removal in real-world applications.