Conductive phthalocyanine-based porous organic polymer as sensing platform for rapid determination of vanillin.

Vanillin (Van) is widely utilized in processed foods and medicines for its appealing scent and multiple therapeutic benefits. However, its overconsumption poses a risk to public health, making its quantification essential for ensuring food and medicine safety and quality. This study introduces a stable and conductive phthalocyanine-based porous organic polymer (NiPc-CC POP), synthesized through a straightforward electrophilic substitution of nickel tetra-amine phthalocyanine (NiTAPc) with cyanuric chloride (CC). Appropriate characterization techniques were employed to determine the morphologies and structures of the synthesized materials. Furthermore, the NiPc-CC POP was applied to devise a sensitive Van detection method. Leveraging the high electrocatalytic activity of NiPc-CC POP toward Van oxidation, a linear response of 0.15-32 µmol L-1 was achieved, along with an exceptional detection limit of 0.10 µmol L-1. The sensor demonstrated high selectivity and stability. Samples of human serum and tablets spiked with Van were analyzed, yielding satisfactory recoveries. Consequently, this work contributes to the advancement of sensitive detection platforms for Van at minimal concentrations.

3D C-Co-N-anchored MWCNTs derived from metal-organic frameworks as high-performance electrochemical sensing platforms for the sensitive detection of adrenaline.

Metal-organic frameworks (MOFs) are composed of metal ions and organic ligands with high specific surface areas, controllable porous structures and abundant metal active sites, showing their extraordinary potential in electrochemical sensors. Here, a 3D conductive network structure (C-Co-N@MWCNTs) is designed by anchoring zeolite imidazole frameworks (ZIF-67) onto multi-walled carbon nanotubes (MWCNTs) and carbonizing them. The C-Co-N@MWCNTs exhibit excellent electron conductivity, a porous structure and considerable electrochemical active sites, which can effectively demonstrate high sensitivity and selectivity in the detection of adrenaline (Ad). The Ad sensor exhibited a low detection limit of 6.7 nmol L-1 (S/N = 3) and a wide linear range of 0.02 µmol L-1-1.0 mmol L-1. The developed sensor also displayed high selectivity, good reproducibility and repeatability. The C-Co-N@MWCNTs electrode was further employed in the detection of Ad in a real sample of human serum, suggesting that it is a promising candidate for electrochemical sensing of Ad.

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.

Novel porous iron phthalocyanine based metal-organic framework electrochemical sensor for sensitive vanillin detection.

Vanillin is widely used as a flavor enhancer and is known to have numerous other interesting properties, including antidepressant, anticancer, anti-inflammatory, and antioxidant effects. However, as excess vanillin consumption can affect liver and kidney function, simple and rapid detection methods for vanillin are required. Herein, a novel electrochemical sensor for the sensitive determination of vanillin was fabricated using an iron phthalocyanine (FePc)-based metal-organic framework (MOF). Scanning electron microscopy and transmission electron microscopy showed that the FePc MOF has a hollow porous structure and a large surface area, which impart this material with high adsorption performance. A glassy carbon electrode modified with the FePc MOF exhibited good electrocatalytic performance for the detection of vanillin. In particular, this vanillin sensor had a wide linear range of 0.22-29.14 µM with a low detection limit of 0.05 µM (S/N = 3). Moreover, the proposed sensor was successfully applied to the determination of vanillin in real samples such as vanillin tablets and human serum.

Blue-light photoelectrochemical sensor based on nickel tetra-amined phthalocyanine-graphene oxide covalent compound for ultrasensitive detection of erythromycin.

In this study, we developed a novel photoelectrochemical (PEC) sensor for the highly sensitive detection of erythromycin by functionalising graphene oxide (GO) with nickel tetra-amined phthalocyanine (NiTAPc) through covalent bonding, which resulted in the formation of NiTAPc-Gr. The fabricated sensor showed a higher PEC efficiency under blue light, exhibiting a peak wavelength of 456 nm, as compared to that of the monomer. Further, the NiTAPc-Gr/indium tin oxide (ITO) sensor exhibited a photocurrent that was 50-fold higher than that for a GO/ITO sensor under the same conditions. Under optimal conditions, the NiTAPc-Gr PEC sensor showed a linear response for erythromycin concentrations ranging from 0.40 to 120.00 µmol L-1, with the minimum limit for detection being 0.08 µmol L-1. Thus, the NiTAPc-Gr sensor exhibited superior performance and excellent PEC characteristics, high stability, and good reproducibility with respect to the sensing of erythromycin. Moreover, it is convenient to use, fast, small, and cheap to produce. Hence, it should find wide use in the analysis of erythromycin in real-world applications.