PTFE/EP Reinforced MOF/SiO2 Composite as a Superior Mechanically Robust Superhydrophobic Agent towards Corrosion Protection, Self-Cleaning and Anti-Icing.

Organic resin cross-linking ZIF-67/SiO2 superhydrophobic (SHPB) multilayer coating was successfully fabricated on metal substrate. The perfluoro-octyl-triethoxy silane (POTS) modified ZIF-67 and SiO2 coating was applied on primary coated polytetrafluoroethylene (PTFE) and epoxy resin (EP) via spray coating method. Here, we present that the robust superhydrophobicity can be realized by structuring surfaces at two different length scales, with a nanostructure design to provide water repellence and a microstructure design to provide durability. The as-fabricated multilayer coating displayed superior water-repellence (CA=167.4°), chemical robustness (pH=1-14) and mechanical durability undergoing 120th linear abrasion or 35th rotatory abrasion cycle. By applying different acidic and basic corrosive media and various weathering conditions, it can still maintain superior-hydrophobicity. To get a better insight of interaction between inhibitor molecules and metal surface, density functional theory (DFT) calculations were performed, showing lower energy gap and increased binding energy of ZPS/SiO2 /PTFE/EP (ZPS=ZIF-67+POTS) multilayer coating compared to the ZIF-67/SiO2 /PTFE/EP, thereby supporting the experimental findings. Additionally, such coatings may be useful for applications such as anti-corrosion, self-cleaning, and anti-icing multi-functionalities.

A review of the growing trend towards heteroatoms-doped carbon dots based on dopamine acting as a hybrid agent and detected analyte.

Dopamine (DA) is a biomolecule that plays a critical part in the functioning of our brains by promoting motivation, maintaining focus, and altering mood. Excessive or low-level concentrations of DA in the human brain led to a dangerous neurological disorder. It is significantly important to trace the precise amount of DA to prevent such risky brain disease. Recently, heteroatoms-doped carbon dots (H-CDs) have attracted great attention for their capacity to detect biomolecules, metal ions, organic solvents, chemical dyes, etc. In this review, we have provided a comprehensive summary of the emerging trends in the heteroatom functional dopamine-doped carbon dots (DA-CDs), which are based on DA used as starting substances or functionalizing agents. Our analysis encompasses a detailed exploration of the synthetic methods, physical and chemical properties of carbon dots derived from dopamine, as well as their diverse range of applications. Additionally, we have also discussed the application of H-CDs in the dopmine detection by using various fluorescent, colorimetric, and electrochemical techniques.

Fluorescence switch based on NIR-emitting carbon dots revealing high selectivity in the rapid response and bioimaging of oxytetracycline.

The abuse of antibiotics has led to serious environmental pollution and the emergence of drug-resistant bacteria surpassing the replacement rate of antibiotics. Herein, near-infrared fluorescent carbon dots (NIR-CDs) were developed to meet the requirements for oxytetracycline (OTC) detection in food and water samples (milk, honey, and lake water) with a detection limit of 0.112 µM. These NIR-CDs, possessing excellent water-solubility, deep tissue penetration ability, and tunable optical properties, exhibit maximum emission at 790 nm (NIR-I window). Unlike traditional CDs, this novel NIR-CDs nanoprobe provides a dual response in the presence of OTC (quenching and bathochromic shifting), without obvious interference from other existing biomolecules and metal ions. Additionally, these NIR-CDs exhibit excellent photostability and multi-resistance under UV irradiation, exceptional pH stability (pH 6-12), reliable long-time exposure, and durability in ionic (NaCl) environments. Moreover, NIR-CDs and NIR-CDs@OTC are nontoxic and were successfully utilized for cell-imaging applications in normal (NIH3T3) and cancer cells (HeLa).