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

Development of isoniazid electrochemical sensor using nickel ferrite - nitrogen and sulfur co-doped graphene quantum dot nanocomposite as a new electrode modifier

This work reports the synthesis of nickel ferrite decorated nitrogen and sulfur co-doped graphene quantum dot (NF@N, S:GQD) and its use as an electrode modifier. The developed NF@N, S:GQD modified glassy carbon electrode (NF@N, S:GQD/GCE) was applied to assess isoniazid (INZ) concentration based on its oxidation at the surface of the proposed electrode. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used as appropriate electrochemical techniques to study the electrochemical behavior of INZ and determine it. Based on combined evidence from surveys, research, and personal results, it is thought that the combination of nickel ferrite and doped graphene quantum dots can synergistically affect results, leading to increased sensitivity and reduced detection limits. This is probably mainly due to the high electrical conductivity of N, S-GQD structure, the electrocatalytic effect of nickel ferrite, and increased surface area resulting from the nano size of the modifier. The optimum conditions for preparing of the modified electrode and determination of INZ are selected by performing electrochemical experiments. The voltammetric response of the sensor is linear from 0.3 to 40 nM INZ under optimal conditions and the detection limit of the sensor is 0.1 nM. The validity and performance of the prepared sensor were confirmed by determining the amount of INZ in the drug and urine as real samples. The composite of doped nanoparticles and nickel ferrite is an innovative modification material to create electrochemical sensors with high sensitivity and selectivity that can be used in pharmaceutical applications.

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.

Hierarchical 3D Snowflake-like Iron Diselenide: A Robust Electrocatalyst for Furaltadone Detection

An electrocatalyst with a large active site is critical for the development of a high-performance electrochemical sensor. This work demonstrates the fabrication of an iron diselenide (FeSe₂)-modified screen-printed carbon electrode (SPCE) for the electrochemical determination of furaltadone (FLD). It has been prepared by the facile method and systematically characterized with various microscopic/spectroscopic approaches. Due to advantageous physiochemical properties, the FeSe₂/SPCE showed a low charge-transfer resistance value of 200 Ω in 5.0 mM [Fe(CN)₆]^3-/4- containing 0.1 M KCl. More importantly, the FeSe₂/SPCE exhibited superior catalytic performance compared to the bare SPCE for FLD sensing based on the electrochemical response in terms of a peak potential of -0.44 V (vs Ag/AgCl (sat. KCl)) and cathodic response current of -22.8 μA. Operating at optimal conditions, the FeSe₂-modified electrode showed wide linearity from 0.01 to 252.2 μM with a limit of detection of 0.002 μM and sensitivity of 1.15 μA μM^-1 cm^-2. The analytical performance of the FeSe₂-based platform is significantly higher than many previously reported FLD electrochemical sensors. Furthermore, the FeSe₂/SPCE also has a promising platform for FLD detection with high sensitivity, good selectivity, excellent stability, and robust reproducibility. Thus, the finding above shows that the FeSe₂/SPCE is a highly suitable candidate for the electrochemical determination of glucose levels for real-time applications such as in human urine and river water samples.