Bio-functionalized silver nanoparticles for selective colorimetric sensing of toxic metal ions and antimicrobial studies

• Green synthesis of AgNPs by Hibiscus Sabdariffa plant extracts.
• Role of sunlight, pH and different parts of plant on the formation of AgNPs.
• Selective colorimetric sensing of potentially toxic Hg2+, Cd2+ and Pb2+ metal ions.
• Direct correlation between AgNPs stability and antimicrobial studies.

Hibiscus Sabdariffa (Gongura) plant extracts (leaves (HL) and stem (HS)) were used for the first time in the green synthesis of bio-functionalized silver nanoparticles (AgNPs). The bio-functionality of AgNPs has been successfully utilized for selective colorimetric sensing of potentially health and environmentally hazardous Hg2+, Cd2+ and Pb2+ metal ions at ppm level in aqueous solution. Importantly, clearly distinguishable colour for all three metal ions was observed. The influence of extract preparation condition and pH were also explored on the formation of AgNPs. Both selectivity and sensitivity differed for AgNPs synthesized from different parts of the plant. Direct correlation between the stability of green synthesized AgNPs at different pH and its antibacterial effects has been established. The selective colorimetric sensing of toxic metal ions and antimicrobial effect of green synthesized AgNPs demonstrated the multifunctional applications of green nanotechnology.

Bio-functionality of green synthesized AgNPs from Hibiscus Sabdariffa plant extracts were successfully utilized for selective colorimetric sensing of potentially health and environmentally toxic metal ions such as Hg2+, Pb2+, Cd2+ in aqueous solution.Figure optionsDownload as PowerPoint slide