Nanomaterials & Nanotechnology
Ryan M Lumod; Khia Jane D Avila; Rolen Brian P Rivera; Miceh Rose A Magdadaro; Noel Lito B Sayson; Felmer S Latayada; Gerard G Dumancas; Rey Y Capangpangan; Arnold C Alguno
Abstract
Gold nanoparticles (AuNPs) have wide-ranging applications across scientific disciplines and industries. However, its conventional synthesis methods pose environmental and health risks, prompting the rise of green chemistry for sustainable and eco-friendly nanoparticle production. Plant extracts rich ...
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Gold nanoparticles (AuNPs) have wide-ranging applications across scientific disciplines and industries. However, its conventional synthesis methods pose environmental and health risks, prompting the rise of green chemistry for sustainable and eco-friendly nanoparticle production. Plant extracts rich in bioactive compounds capable of reducing and capping nanoparticles have emerged as promising alternatives. Among these sources, Aloe vera, renowned for its diverse phytochemicals, presents an attractive avenue for nanoparticle synthesis devoid of hazardous reagents. This study delves into the one-step green synthesis of AuNPs employing aloe vera extract and examines their antibacterial efficacy against Gram-positive and Gram-negative bacteria. The synthesized AuNPs exhibited a reddish-purple color with localized surface plasmon resonance peaks at 529 nm, 535 nm, and 541 nm, corresponding to varying gold precursor concentrations (0.1 mM, 0.3 mM, and 0.5 mM). FTIR analysis confirmed the presence of bioactive compounds involved in the reduction and capping of AuNPs. Characterization via Transmission Electron Microscopy showed spherical AuNPs ranging from 10 nm to 39 nm in diameter, with stability indicated by zeta potential values of -37.3 mV, -28.7 mV, and -24.7 mV for the respective concentrations. Notably, AV-AuNPs demonstrated significant antibacterial activity, with inhibition zones of 34 mm against E. coli and 18 mm against B. subtilis, attributed to their ability to penetrate bacterial membranes and induce cell lysis.
Ayushi Tiwari; Anshuman Mishra
Abstract
Diabetes mellitus is a serious life-time health issue which has been increasing among the greater population, approximately 285 million people carrying this disease worldwide. In this study, we have functionalised the gold nanoparticles (AuNPs) with biocatalytic enabled optical property, it is the subject ...
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Diabetes mellitus is a serious life-time health issue which has been increasing among the greater population, approximately 285 million people carrying this disease worldwide. In this study, we have functionalised the gold nanoparticles (AuNPs) with biocatalytic enabled optical property, it is the subject of the study for detecting glucose towards the development of photometric nano-transducer. The citrate capped AuNPs were used to warrant the electrostatic self-assembly of glucose oxidase (GOx) in the colloidal state. Glucose biocatalysis was studied through the nano-optical function of glucose on the surface of AuNPs. Using surface plasmonic resonance as analytical technique, we have determined the molecular binding interaction between glucose molecule and AuNPs surface. Based on the visible spectrum, successful immobilization of GOx onto AuNPs was demonstrated. The GOx functionalized AuNP exhibits catalytic activities for the oxidation of glucose and resulting change in the absorption peak of colloidal bio-assembly. It was observed that the absorbance at 520 nm was proportional to the concentration of glucose in the test samples. The Lambert-Beer law expresses the linear relationship between the absorbance and glucose concentration at a fixed wavelength, i.e., λmax at 520 nm. The precise detection of glucose is essential to monitor the biological level of glucose in the body. It can be concluded that the nano-(bio) gold surface exhibits a rapid photometric response with changes of glucose concentration in the test samples.
Divya Sachdev; Sandeep Singh;Renu Pasricha; Shweta Gupta; Veeresh Kumar
Abstract
Surface tension mediated U-shaped interlinked diammine network (spermine) assembled at the air-water interface, when interacted with aqueous functionalized gold nanoparticles (AuNPs), form ring like nanogold structures. These electrostatic force guided self-assembies of the ligand diammine with gold ...
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Surface tension mediated U-shaped interlinked diammine network (spermine) assembled at the air-water interface, when interacted with aqueous functionalized gold nanoparticles (AuNPs), form ring like nanogold structures. These electrostatic force guided self-assembies of the ligand diammine with gold provides a facile route for control on the nanostructure formation while portraying double linkage ability of the diammine (here spermine). Pressure-area isotherm of controlled multilayer formation of spermine linked gold NPs (spermine-AuNPs) were studied and characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy and Transmission electron microscopy (TEM). The TEM micrographs clearly elucidate the formation of ring like networks of gold NPs under the influence of spermine. Furthermore we believe that these spermine-AuNPs will surely have supportive role as a bio-diagnostic material for ultra-sensitive biological detection and pave way for a novel route for assembly fabrication.
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