Using a Modified Polyamidoamine Fluorescent Dendrimer for Capturing Environment Polluting Metal Ions Zn2+, Cd2+, and Hg2+: Synthesis and Characterizations

Abstract

One of the most pressing global concerns is how to provide a clean environment for future generations given the exacerbation of urban, agricultural, industrial, and economic activities due to the escalating size of the global population. A polyamidoamine (PAMAM) dendrimer peripherally modified with 4-N,N′-dimethylethylenediamine-1,8-naphthalmide as a chromophore was synthesized and utilized to capture hazardous heavy metal ions. This modified fluorescent dendrimer (FCD) was complexed with Group 12 metal ions (Zn2+, Cd2+, and Hg2+) at a 2:1 (metal: FCD) ratio. Electronic absorption, fluorescence emission, Infra-red (IR), and nuclear magnetic resonance (1H NMR) spectroscopies, conductivity, CHN elemental, thermogravimetry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses were used to characterize the resulting metal complexes. These assays revealed that the synthesized complexes were yellow-colored, thermally stable, nanoscale-sized, and composed of [M2FCD]·4Cl2. Considerable spectral shifts were observed in the emission and absorption spectra of the FCD molecule after binding the Zn2+ ions, which can be used to differentiate the Zn2+ complex from the other two complexes. This work provides basic data to facilitate the detection, quantification, and removal of environmentally hazardous heavy metal ions through complexation with a fluorescent dendrimer.

Extended-Spectrum-β-Lactamase- and AmpC-Producing Escherichia coli in Domestic Dogs: Spread, Characterisation and Associated Risk Factors

“…The choice was to investigate these four AMR genes due to their most frequently detection when ESBL/AmpC E. coli was isolated not only in dogs [5,17,[20][21][22] but also in other animal species [31][32][33] as well as in humans [34][35][36]. Concerning our study area, the only data currently available about the presence of these resistant genes in ESBL/AmpC E. coli are those from a study on wild boar and even in that wild species bla CTX-M was the most frequently detected with a prevalence of 12.3% (185/1504) followed by bla TEM (6.98%, 105/1504), bla CMY (0.86%, 13/1504) and bla SHV (0.47%, 7/1504) [37]. In this regard, focusing on the spread of AMR genes in humans, during 1990s, the most ESBLs were mutants of the classical TEM-1, -2 and SHV-1 enzymes [38] and bla TEM was the most frequent isolated among nosocomial strains [39].…”

Molecular Basis of Endometriosis and Endometrial Cancer: Current Knowledge and Future Perspectives

“…The etiology of endometriosis is largely unknown. Previous research has shown that endometriosis is prevalent after menarche and dramatically drops after menopause, which has led researchers to believe that the disorder is estrogen-and progesterone-dependent [26,27,29].…”

Role of PARP in TNBC: Mechanism of Inhibition, Clinical Applications, and Resistance

“…The DSB ends are firstly resected by the MRN ( Mre11–Rad50–Nbs1 ) complex with EXO1 , DNA2, and MUS8 , leading to the development of the ssDNA and pushing the cells towards HR [ 92 , 93 ]. Subsequently, the resected DNA ends are coated by the hyperphosphorylated single-stranded DNA binding protein A (RPA) [ 94 , 95 ]. The variant H2AX is stimulated and phosphorylated by apical kinases, such as ATM and ATR (ATM and Rad3-related).…”