Electrocatalytic activity of a push pull Co(II) phthalocyanine in the presence of graphitic carbon nitride quantum dots

Exploring 1T/2H MoS2 quantum dots modified 2D CoPx nanosheets for efficient electrocatalytic hydrogen evolution reaction

The exploration of multiphases and 0D/2D heterojunction in transition metal phosphides (TMPs) and transition metal sulfides (TMDs) is of major interest for hydrogen evolution reaction (HER). Herein, a novel combination route where 0D mixed-phased 1T/2H molybdenum sulfide quantum dots (MoS2 QDs) are uniformly anchored on the 2D CoPx nanosheets is developed. MoS2 QDs and CoPx were prepared via hydrothermal method and mixed with different ratios (Mo:Co ratios of 2:1, 1:1, and 1:2) and annealed under different temperatures to modulate their application in acidic HER processes. Specifically, 2Mo/1Co exhibited advanced performance for HER in 0.5 M H2SO4 solution and required 14 mV to deliver 10 mA cm-2 and revealed a descended Tafel slope of 75.42 mV dec-1 with 240 h stability except obvious deactivation. The successful design and construction of 0D/2D mixed-dimensional materials would broaden the application of MoS2 and CoPx for electrocatalytic hydrogen evolution.

Wound recovery efficacy of retinol based-micellar formulations in an organotypic skin wound model

Impairment of the skin's structural integrity initially results in acute wounds which can become chronic if timely wound closure is not achieved. Chronic wounds (CWs) affect more than 1% of the global population with increasing cases of this condition due to the ageing population. Current wound management relies on debridement, hyperbaric oxygen, antibiotics, and wound dressings, which lack early intervention and specificity. Herein, antibiotics-free retinol-based micellar formulations (RMF) were made and their wound healing efficacy were investigated in vitro. Five different formulations with retinol contents of 0.3% and 1% against a placebo were topically applied to an organotypic full-thickness skin wound model (FT-SWM, MatTek®) with a 3 mm punch wound, and maintained in an incubator for 6 days. The histological analysis of the FT-SWM was conducted at depths of 60 µm and 80 µm. It was found that all the micellar retinol formulations accelerated wound bed contraction, with 0.3% RMF demonstrating the highest efficacy. At the depths of 60 µm and 80 µm, the 0.3% RMF exhibited inner wound diameter contraction of 58% and 77%, respectively, in comparison to the placebo showing 15% and 8%. The RMF significantly accelerated wound healing and can thus be a potential early intervention for speedy wound recovery. It should be pointed out that these results were obtained based on a small sample size and a large sample size will be explored to further validate the results.

Nonenzymatic Lactic Acid Detection Using Cobalt Poly-phthalocyanine/Carboxylated Multiwalled Carbon Nanotube Nanocomposites Modified Sensor

In this study, a novel cobalt polyphthalocyanine/carboxylic acid functionalized multiwalled carbon nanotube nanocomposite (CoPPc/MWCNTs-COOH) to detect lactic acid was successfully fabricated. The nanocomposite was systematically characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet–visible absorption spectroscopy, and X-ray photoelectron spectroscopy. The nanocomposite provided excellent conductivity for effective charge transfer and avoided the agglomeration of MWCNTs-COOH. The electrochemical surface area, diffusion coefficient and electron transfer resistance of the CoPPc/MWCNTs-COOH glassy carbon electrode (CoPPc/MWCNTs-COOH/GCE) were calculated as A = 0.49 cm2, D = 9.22 × 10−5 cm2/s, and Rct = 200 Ω, respectively. The lactic acid sensing performance of the CoPPc/MWCNTs-COOH was evaluated using cyclic voltammetry in 0.1 M PBS (pH 4). The results demonstrated that the novel electrode exhibited excellent electrochemical performance toward lactic acid reduction over a wide concentration range (10 to 240 μM), with a low detection limit (2 μM (S/N = 3)), and a reasonable selectivity against various interferents (ascorbic acid, uric acid, dopamine, sodium chloride, glucose, and hydrogen peroxide). Additionally, the electrode was also successfully applied to quantify lactic acid in rice wine samples, showing great promise for rapid monitoring applications.

The electrochemical detection of prostate specific antigen on glassy carbon electrode modified with combinations of graphene quantum dots, cobalt phthalocyanine and an aptamer

Herein, a novel aptasensor is developed for the electrochemical detection of prostate specific antigen (PSA) on electrode surfaces modified using various combinations of a Cobalt phthalocyanine (CoPc), an aptamer and graphene quantum dots (GQDs). Electrochemical impedance spectroscopy (EIS) as well as differential pulse voltammetry (DPV) are employed for the detection of PSA. In both analytical techniques, linear calibration curves were observed at a concentration range of 1.2-2.0 pM. The glassy carbon electrode where CoPc and GQDs are placed on the electrode when non-covalently linked followed by addition of the aptamer (GQDs-CoPc(ππ)-aptamer (sequential)) showed the best performance with a limit of detection (LoD) as low as 0.66 pM when using DPV. The detection limits were much lower than the dangerous levels reported for PSA in males tested for prostate cancer. This electrode showed selectivity for PSA in the presence of bovine serum albumin, glucose and L-cysteine. The aptasensor showed good stability, reproducibility and repeatability, deeming it a promising early detection device for prostate cancer.

The electrochemical detection of prostate specific antigen on glassy carbon electrode modified with combinations of graphene quantum dots, cobalt phthalocyanine and an aptamer

Herein, a novel aptasensor is developed for the electrochemical detection of prostate specific antigen (PSA) on electrode surfaces modified using various combinations of a Cobalt phthalocyanine (CoPc), an aptamer and graphene quantum dots (GQDs). Electrochemical impedance spectroscopy (EIS) as well as differential pulse voltammetry (DPV) are employed for the detection of PSA. In both analytical techniques, linear calibration curves were observed at a concentration range of 1.2-2.0 pM. The glassy carbon electrode where CoPc and GQDs are placed on the electrode when non-covalently linked followed by addition of the aptamer (GQDs-CoPc(ππ)-aptamer (sequential)) showed the best performance with a limit of detection (LoD) as low as 0.66 pM when using DPV. The detection limits were much lower than the dangerous levels reported for PSA in males tested for prostate cancer. This electrode showed selectivity for PSA in the presence of bovine serum albumin, glucose and L-cysteine. The aptasensor showed good stability, reproducibility and repeatability, deeming it a promising early detection device for prostate cancer.

A career in photophysicochemical and electrochemical properties of phthalocyanine — a Linstead Career Award paper

This manuscript highlights the author’s contributions to phthalocyanine chemistry, especially the applications based on their electrochemistry and photophysicochemistry. In particular, the use of phthalocyanines as electrocatalysts and photocatalysts is presented. For photocatalysis, photodynamic antimicrobial chemotherapy and pollution control using green technologies are highlighted. For electrocatalysis the phthalocyanines are employed for the detection of pollutants and environmentally important molecules. Phthalocyanines are combined with nanomaterials for improved photocatalysis and electrocatalysis.