Recycling of silver nanoparticles from electronic waste via green synthesis and application of AgNPs-chitosan based nanocomposite on textile material.

The main thrust of this project is the fabrication of silver nanoparticles (AgNPs) from electronic waste (PCB board) and applying it on 100% cotton fabric as an antimicrobial agent. The nanoparticle formation of silver was done by green synthesis way using an aqueous leaf extract of Eichhornia crassipes. Furthermore, chitosan was also applied to the fabric with silver nanoparticles by coating. FTIR and SEM tests characterized the fabricated silver nanoparticles, and antimicrobial tests were followed by the disc diffusion method. The SEM analysis showed an average particle size of 76.91 nm. The FTIR analysis showed the successful reduction of silver nanoparticles and the bonding with chitosan and cellulose. Besides, the EDX reports confirmed the existence of AgNPs by indicating a strong signal in the silver region. In addition, SEM characteristics analysis confirmed the uniform deposition of silver nanoparticles. Finally, the antimicrobial property was tested against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The antimicrobial result was found satisfactory in the case of green-synthesized recycled AgNPs. However, the effectiveness was not observed to be higher than green-synthesized pure AgNPs. In this study, the zone of inhibition of AgNPs was also compared to the reference antibiotics Ciprofloxacin.

Mapping the Progress in Surface Plasmon Resonance Analysis of Phytogenic Silver Nanoparticles with Colorimetric Sensing Applications.

Nanotechnology is gaining enormous attention as the most dynamic research area in science and technology. It involves the synthesis and applications of nanomaterials in diverse fields including medical, agriculture, textiles, food technology, cosmetics, aerospace, electronics, etc. Silver nanoparticles (AgNPs) have been extensively used in such applications due to their excellent physicochemical, antibacterial, and biological properties. The use of plant extract as a biological reactor is one of the most promising solutions for the synthesis of AgNPs because this process overcomes the drawbacks of physical and chemical methods. This review article summarizes the plant-mediated synthesis process, the probable reaction mechanism, and the colorimetric sensing applications of AgNPs. Plant-mediated synthesis parameters largely affect the surface plasmon resonance (SPR) characteristic due to the changes in the size and shape of AgNPs. These changes in the size and shape of plant-mediated AgNPs are elaborately discussed here by analyzing the surface plasmon resonance characteristics. Furthermore, this article also highlights the promising applications of plant-mediated AgNPs in sensing applications regarding the detection of mercury, hydrogen peroxide, lead, and glucose. Finally, it describes the future perspective of plant-mediated AgNPs for the development of green chemistry.