Covalent Immobilisation of a Nanoporous Platinum Film onto a Gold Screen-Printed Electrode for Highly Stable and Selective Non-Enzymatic Glucose Sensing

Progress in the development of commercially available non-enzymatic glucose sensors continues to be problematic due to issues regarding selectivity, reproducibility and stability. Overcoming these issues is a research challenge of significant importance. This study reports a novel fabrication process using a double-layer self-assembly of (3 mercaptopropyl)trimethoxysilane (MPTS) on a gold substrate and co-deposition of a platinum–copper alloy. The subsequent electrochemical dealloying of the less noble copper resulted in a nanoporous platinum structure on the uppermost exposed thiol groups. Amperometric responses at 0.4 V vs. Ag/AgCl found the modification to be highly selective towards glucose in the presence of known interferants. The sensor propagated a rapid response time <5 s and exhibited a wide linear range from 1 mM to 18 mM. Additionally, extremely robust stability was attributed to enhanced attachment due to the strong chemisorption between the gold substrate and the exposed thiol of MPTS. Incorporation of metallic nanomaterials using the self-assembly approach was demonstrated to provide a more reproducible and controlled molecular architecture for sensor fabrication. The successful application of the sensor in real blood serum samples displayed a strong correlation with clinically obtained glucose levels.

Metallic Nanomaterials with Mimic Oxidoreductase Enzyme Activity: New Insight for Sensing and Biosensing

: It has been found that the metallic nanomaterials with mimetic enzyme activity have multiple oxidoreductase-like enzyme activities, such as horseradish peroxidase, glutathione peroxidase, catalase, oxidase, glucose oxidase, etc. In recent years, many applied researches based on these nanozymes have been reported. This review summarizes three kinds of representative nanozymes, including metal nanomaterials, MOFs, metal oxide nanomaterials, and their corresponding applications in sensing and biosensing.

Electrochemical Detection of Glucose Molecules Using Laser-Induced Graphene Sensors: A Review

This paper deals with recent progress in the use of laser-induced graphene sensors for the electrochemical detection of glucose molecules. The exponential increase in the exploitation of the laser induction technique to generate porous graphene from polymeric and other naturally occurring materials has provided a podium for researchers to fabricate flexible sensors with high dynamicity. These sensors have been employed largely for electrochemical applications due to their distinct advantages like high customization in their structural dimensions, enhanced characteristics and easy roll-to-roll production. These laser-induced graphene (LIG)-based sensors have been employed for a wide range of sensorial applications, including detection of ions at varying concentrations. Among the many pivotal electrochemical uses in the biomedical sector, the use of these prototypes to monitor the concentration of glucose molecules is constantly increasing due to the essentiality of the presence of these molecules at specific concentrations in the human body. This paper shows a categorical classification of the various uses of these sensors based on the type of materials involved in the fabrication of sensors. The first category constitutes examples where the electrodes have been functionalized with various forms of copper and other types of metallic nanomaterials. The second category includes other miscellaneous forms where the use of both pure and composite forms of LIG-based sensors has been shown. Finally, the paper concludes with some of the possible measures that can be taken to enhance the use of this technique to generate optimized sensing prototypes for a wider range of applications.

A Review of the EU’s Regulatory Framework for the Production of Nano-Enhanced Cosmetics

Literature has suggested metallic nanomaterials (NMs) for a multitude of applications in cosmetic products, either as active ingredients or excipients. Alike most high-paced industrial sectors, cosmetology continues to capitalize on its unique properties/functions (e.g., as UV-filters, colorants, etc.), adding value to a wide range of products. However, as a result of their nano-scale, NMs do not always conform with the handling guidelines of their bulk counterparts, nor do conventional analytical methods account for their complex physicochemical and biological interactions. Among others, metallic nanoparticles have attracted the interest of many over the years due to their unique features, but possible precautions should be considered because of their bio-persistent nature. As a result, it is prevalent to consider a nano-specific framework, to regulate the use of NMs and the production of nano-enhanced cosmetics. To address this, we provide insight into the NMs that are currently used in the EU market, with a focus on metallic NMs, while analyzing the underlying legislation and relevant Opinions of the Scientific Committee on Consumer Safety (SCCS), from a scientific and commercial perspective. Even though the current Cosmetics Regulation (EU Regulation No 1223/2009) already entails specific provisions on NMs, cosmetic products incorporating unauthorized NMs have been repeatedly commercialized in the European Union. Considering the potential risks of NMs if they are mishandled, we provide an analysis of the risk assessment, as stated in Article 16 of the Cosmetics Regulation, to serve as a guideline for the future growth of nano-enhanced products. Based on the limited integration of metallic NMs along with multiple non-metallic NPs into cosmetic products, the attention of the community is directed towards coordinating efforts on the integration of metallic NMs into cosmetics.