Deciphering the sensing of α-amyrin acetate with hs-DNA: a multipronged biological probe

Blue light-emitting fluorene–dendron hybridized polymers: optophysical features

In this manuscript, we have demonstrated an efficient and rapid synthetic strategy for preparation of new fluorene–dendron-hybridized blue light-emitting polymers P1–P7 by the reaction of 9,9 long-chain dialkylated fluorenes M2–M8 with dendronized monomer (M1) under microwave-assisted reaction condition. These fluorene–dendron-hybridized polymers P1–P7 were characterized using different spectroscopic techniques. Furthermore, the optophysical properties of these polymers P1–P7 were studied which revealed that these synthesized polymers P1–P7 have potential to emerge as capable materials in the development of diodes, particularly for blue light emission. In the future, similar approaches would be utilized for preparation of light-emitting polymer composite.

Economical gold recovery cycle from bio-sensing AuNPs: an application for nanowaste and COVID-19 testing kits

We report the controlled growth of biologically active compounds: gold nanoparticles (AuNPs) in various shapes, including their green synthesis, characterization, and studies of their applications towards biological, degradation and recycling. Using spectroscopic methods, studies on responsive binding mechanisms of AuNPs with biopolymers herring sperm deoxyribonucleic acid (hsDNA), bovine serum albumin (BSA), dyes degradation study, and exquisitely gold separation studies/recovery from nanowaste, COVID-19 testing kits, and pregnancy testing kits are discussed. The sensing ability of the AuNPs with biopolymers was investigated via various analytical techniques. The rate of degradation of various dyes in the presence and absence of AuNPs was studied by deploying stirring, IR, solar, and UV-Vis methods. AuNPs were found to be the most active cytotoxic agent against human breast cancer cell lines such as MCF-7 and MDAMB-468. Furthermore, an economical process for the recovery of gold traces from nanowaste, COVID-19 detection kits, and pregnancy testing kits was developed using inexpensive and eco-friendly α-cyclodextrin sugar. This method was found to be easy and safest in comparison with the universally accepted cyanidation process. In the future, small gold jewelry makers and related industries would benefit from the proposed gold-recycling process and it might contribute to their socio-economic growth. The methodologies proposed are also beneficial for trace-level forensic investigation.

Exploring the interaction of guanidine ligands Amiloride, Rimeporide and Cariporide with DNA for understanding their role as inhibitors of Na+/H+ exchangers (NHEs): A spectroscopic and molecular docking investigation

The inhibition of Na⁺/H⁺ Exchangers (NHEs) has shown efficacy in the pathology of several diseases like tumors, cardiovascular, and neurological disorders. The role of guanidine ligands such as amiloride, cariporide, and rimeporide as NHE inhibitors is very well documented but their interaction studies with genomic DNA are still unexplored. In this study, a combination of various biophysical and molecular docking studies was employed to investigate their binding aspects.UV-Visible, fluorescence, and circular dichroism (CD) studies indicated that guanidine ligands bind to the grooves of Calf Thymus DNA (ctDNA). Fluorescence titration studies depict that amiloride binds to ctDNA with a binding constant in the order of 10² M^-1 and free energy change (ΔG⁰) of -14.05 KJ mol^-1. Competitive fluorescence studies indicated the minor groove binding property of amiloride, whereas major groove binding mode was deduced for rimeporide and cariporide. Molecular docking studies were also found to be in accordance with the experimental results, revealing the information about the binding energy of the guanidine ligand-ctDNA complex. The docked structures depicted binding energy of -6.4 kcal mol^-1 for amiloride and - 6.6 kcal mol^-1 for rimeporide and cariporide. Such physicochemical studies of DNA-ligand interactions may facilitate the understanding of the mechanisms of NHE inhibition.

Click gold quantum dots biosynthesis with conjugation of quercetin for adenocarcinoma exertion

We developed a cost-effective and eco-friendly click biosynthesis of small molecule quercetin–gold quantum dots (QRT–AuQDs) involving quick conjugation using an ultrasonication method at ambient temperature by utilizing QRT and gold ions in the proportion of 0.1 : 1 (molar ratio). A comparatively very short amount of time (60 seconds) was required as compared to conventional procedures. The present biomimetics research relates to the isolation of bioactive QRT by the circularly spread silica gel layer technique (CSSGLT) and characterization (UV-Vis, FTIR, NMR and DSC analysis). Characterization of the synthesized QRT–AuQDs conjugated complex was carried out by UV-Vis, HR-TEM, DLS, zeta potential and X-ray diffraction. The main objective of the present work was to study the comparative anticancer activity of QRT and QRT–AuQDs on human lung cancer HOP-62 and leukemia K-562 cell lines. The results suggested that QRT–AuQDs showed potential for applications in anticancer treatment and were found to be a more cytotoxic agent in comparison to QRT, causing > 50% inhibition of cancer cells at the concentration < 10⁻⁷ M. Hence, small molecule conjugated QRT–AuQDs can be used as a promising material for biomedical, bioengineering and anti-infectives applications.

A cost-effective and eco-friendly click biosynthesis of small molecule quercetin–gold quantum dots (QRT–AuQDs) was developed involving quick conjugation, using an ultrasonication method at ambient temperature by utilizing QRT and gold ions in the molar ratio 0.1 : 1.