Highly Selective Colorimetric Sensor of Mercury(II) Ions by Andrographolide-Stabilized Silver Nanoparticles in Water and Antibacterial Evaluation

Abstract

Silver nanoparticles (AgNPs) are well known for their exceptional properties and versatility in various applications. This study used andrographolide as a biochemical stabilizer to synthesize AgNPs (andro-AgNPs). The andro-AgNPs were characterized by using UV−vis spectroscopy, revealing a surface plasmon resonance peak at 440 nm. Fourier transform infrared spectroscopy was also used to confirm the presence of AgNPs. Transmission electron microscopy was used to investigate the morphology of andro-AgNPs, which showed a spherical shape with an average diameter of 18.30 ± 5.57 nm (n = 205). Andro-AgNPs were utilized as a colorimetric sensor to detect mercury ions (Hg 2+ ) in water, and the optimized detection conditions were evaluated using UV−vis spectroscopy with a linear range of 15− 120 μM. The limit of detection and the limit of quantification for Hg 2+ detection were found to be 11.15 and 37.15 μM, respectively. Furthermore, andro-AgNPs exhibited antibacterial properties against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The results imply that andro-AgNPs hold promising potential for future biomedical applications.

Vitis heyneana extract mediated synthesis of silver nanoparticles with high bioactive and colorimetric sensing properties

“…More recently, the synthesis of AgNPs using plant extracts [1][2][3][4], algae [5,6], fungi [7], and organic compounds as reducing and stabilizing agents has been becoming an important strategy to circumvent the use of hazardous chemicals, improve the NP biocompatibility of AgNPs, and expand their applications. To date, many of plant species [1] such as Pelargonium hortorum [1], Equisetum difusum [2], Tabebuia rosea [3] and Piper chaudocanum [4] and pure organic compounds including quercetin [8,9], rutin [10], and andrographolide [11,12] have been utilized for the synthesis of AgNPs with various sizes and morphologies. To advance the practical uses of the NPs, their surface can be functionalized with organic groups to enhance their bioactivities and improve the selective detection of various analytes.…”