Search

Green synthesis of silver nanoparticles (AgNPs) is carried out using silver nitrate as a silver precursor and sugarcane leaves extract containing phenolic compound as reducing agents. Effect of sugarcane leaves extraction temperature, i.e., room temperature, 60° and 90 °C on phenolic compound content was investigated. The characteristics of the as-synthesized AgNPs were studied by UV–Vis spectrophotometer, XRD, FTIR and TEM confirming the formation of AgNPs with an average particle size of 16.9 ± 4.7 nm. The AgNPs were further evaluated as ammonia and hydrogen peroxide solution sensing. The results revealed that the developed AgNPs using green synthesis had an ability to detect hydrogen peroxide and ammonia for relatively low concentration which can be observed by both UV–Vis spectrophotometer and naked eye. Moreover, the results also revealed the detectability of AgNPs to those toxic agents after storage for 14 days. The results indicated that the green synthesis of AgNPs is value-added to the agricultural waste, for example, sugarcane leaves which can be further applied for bio-sensors of ammonia and hydrogen peroxide sensing. [ABSTRACT FROM AUTHOR]

Bacterial wound infections remain a significant health issue of great concern. Hence, there is a need to develop a novel material with antibacterial properties and smart functions. In this study, the effects of silver nanoparticles content (AgNPs) on properties of photothermal and pH-responsive nanocomposite hydrogels were investigated. The nanocomposite hydrogel samples were prepared using cassava starch waste modified by carboxymethylation (CMS), and mixed with poly vinly alcohol (PVA) and tannic acid (TA). The presence of AgNPs in the hydrogel samples enhanced antibacterial activities and photothermal conversion ability. The use of as-prepared hydrogel using 200 mM silver nitrate (H-AgNPs-200) combined with near infrared (NIR) radiation produced 100 % antibacterial efficiency for Escherichia coli (E.coli) and 98.2 % for Staphylococcus aureus (S.aureus). Furthermore, the H-AgNPs-200 also provided the highest storage modulus at 8.78 kPa. The obtained nanocomposite hydrogel was shown to exhibit pH-responsive release of TA. Under NIR radiation, higher release of TA at different pH was observed. The cytotoxicity study indicated that the nanocomposite hydrogels had good biocompatibility. Hence, the development of nanocomposite hydrogel-based CMS from cassava starch waste/PVA/AgNPs is a promising and sustainable approach where agro-waste product is used as the base material for medical application in wound dressing. [Display omitted] [ABSTRACT FROM AUTHOR]