Molecular adsorption studies of benzidine on novel Kagome antimonene nanosheets - Insights based on first-principles DFT calculations

On the interface between biomaterials and two-dimensional materials for biomedical applications

Two-dimensional (2D) materials have garnered significant attention due to their ultrathin 2D structures with a high degree of anisotropy and functionality. Reliable manipulation of interfaces between 2D materials and biomaterials is a new frontier for biomedical nanoscience and combining biomaterials with 2D materials offers a promising way to fabricate innovative 2D biomaterials composites with distinct functionality for biomedical applications. Here, we focus exclusively on a summary of the current work in the interface investigation of 2D biomaterials. Specifically, we highlight extraordinary features that make 2D materials so desirable, as well as the molecular level interactions between 2D materials and biomaterials that have been studied thus far. Furthermore, the approaches for investigating the interface characteristics of 2D biomaterials are presented and described in depth. To capture the emerging trend in mass manufacturing of 2D materials, we review the research progress on biomaterial-assisted exfoliation. Finally, we present a critical assessment of newly developed 2D biomaterials in biomedical applications.

Conformational analysis and concentration detection of linuron: Spectroscopic NMR and SERS study

Linuron is a commonly used organic herbicide which is used in plant growth control. Due to its potential health concerns, the characterization and monitoring of linuron have been a subject of several studies. In this work, we employed nuclear magnetic resonance (NMR) and Raman spectroscopic techniques supported with the density functional theory (DFT) to investigate the conformational behavior and electronic aspects of linuron. The selective nuclear Overhauser effect (SelNOE) spectra confirmed that linuron exists predominantly in the anti configuration and is facilitated with a weak intramolecular hydrogen bonding between the acidic amide proton and oxygen of methoxy moiety. Quantum chemical results showed that the corresponding syn form of the molecule is 8.5 kcal/mol less stable. Further, the surface enhanced Raman scattering (SERS) technique using gold nanoparticles (AuNPs) was implemented as a potential spectroscopic protocol for the concentration monitoring of trace linuron. The Raman responses of four vibrational modes, namely CC stretching, CN stretching, N-H rocking and ring deformation, were successfully enhanced with an excellent linear concentration-intensity dependency. The aromatic CC stretching vibration at 1595 cm^-1 in the Raman spectra has demonstrated the highest enhancement factor (6.5 × 10⁴) and the lowest limit of detection (10^-7 M). The interaction of linuron with the gold nanocluster was simulated by establishing a simple DFT model which predicted that the most pronounced binding with the gold atom takes place at the benzene ring.

Silver cluster (Ag6) decorated coronene as non-enzymatic sensor for glucose and H2O2

Silver-graphene quantum dots are promising electrochemical sensors due to their unique electronic properties. Herein, we report the comprehensive DFT study to explore the electronic properties of silver cluster (Ag₆) decorated coronene as model for silver graphene quantum dots. The current study aims to investigate the sensing ability of silver-coronene complex for non-enzymatic electrochemical detection of glucose & H₂O₂. The stability of the complexes of analytes with silver decorated coronene is supported by their greater interaction energies (-36.7 to -44.9 kcal mol^-1)_. NBO charge analysis and charge decomposition analysis (CDA) reveal donor-acceptor charge transfer interactions in the complexes. Frontier molecular orbital analysis illustrates that charge is transferred from analytes to silver decorated coronene during excitation from HOMO to LUMO. The Uv-visible results show that λ_max is red shifted during interactions of analytes with silver decorated coronene. The NCI analysis illustrates the strong non-covalent (M … O) and unusual M … H-O interactions in the complexes. The precedent sensing performance of Ag₆-coronene might be attributed to the synergistic effect of both silver clusters and coronene in the composite. The evaluated results validate the excellent sensing ability of silver-graphene quantum dots for the detection of glucose & H₂O₂. The outcome of the current study and its prospects will open the avenue for the rational development of smart sensors.