Green synthesis of CuO nanoparticles using Hibiscus sabdariffa L. extract to treat wastewater in Soba Sewage Treatment Plant, Sudan.

Looking for a cost-effective and ecofriendly method for wastewater treatment is a global challenge. Therefore, this study investigated the removal of wastewater pollutants using copper oxide nanoparticles (CuONPs). CuONPs synthesized by a green solution combustion synthesis (SCS) and characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FT-IR), powder X-ray diffraction analysis (PXRD), and scanning electron microscopy (SEM) techniques. PXRD showed nanoparticle sizes ranging from 10 to 20 polycrystalline patterns indexed with two peaks corresponding to (111) and (113) reflections of the face-centered cubic CuO crystal. The energy-dispersive spectroscopy analysis obtained in conjunction with SEM analysis proved the presence of Cu and O atoms at 86.3 and 13.6%, respectively, confirming the reduction and capping of Cu with Hibiscus sabdariffa extract's phytochemicals. The CuONPs proved to be a promising decontaminant for wastewater found to reduce biochemical oxygen demand (BOD) and chemical oxygen demand (COD) by 56%, and very efficient in reducing both the total dissolved matter (TDS) and conductivity (σ) by 99%. The CuONPs removed simultaneously chromium, copper, and chloride with respective percentages of 26, 78.8, and 78.2%. Green synthesis of nanoparticles is a simple, rapid, cost-effective, and ecofriendly method that successfully removed contaminants from wastewater.

Amplified label-free electrical detection of DNA hybridization.

A new protocol is described for amplifying label-free electrochemical measurements of DNA hybridization based on the enhanced accumulation of purine nucleobases in the presence of copper ions . Such electrical DNA assays involve hybridization of the target to inosine-substituted oligonucleotide probes (captured on magnetic beads), acidic dipurinization of the hybrid DNA, and adsorptive chronopotentiometric stripping measurements of the free nucleobases in the presence of copper ions. Both amplified adenine and guanine peaks can be used for detecting the DNA hybridization. The dramatic signal amplification advantage of this type of detection has been combined with efficient magnetic removal of non-complementary DNA, use of microliter sample volumes and disposable transducers. Factors influencing the signal enhancement were assessed and optimized. A detection limit of 40 fmol (250 pg) was obtained with 10 min hybridization and 5 min adsorptive-accumulation times. The advantages of this procedure were demonstrated by its application in the detection of DNA segments related to the BRCA1 breast cancer gene. The copper enhancement holds great promise not only for the detection of DNA hybridization, but also for trace measurement of nucleic acids.