ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Hydrothermal decoration of nano-silver on the surface of galactomannan-modified ZnO and their catalytic, bactericidal and biosensing applications

Vedashree Sirdeshmukh, Harshada Dhamdhere, Amruta Kakade, Amol Kahandal, and Chandrakant K. Tagad

MIT School of Bioengineering Sciences & Research, MIT Art, Design and Technology University, Pune, India

E-mail: cktagad@gmail.com

Received: 11 November 2022  Accepted: 29 April 2023

Abstract:

Polysaccharide-based bio-templates are gaining considerable attention for synthesizing metal and metal oxide NPs. In the present study, Ag@ZnO was synthesized by hydrothermal reduction of Ag⁺ to Ag⁰ on the polysaccharide-modified ZnO nanoparticles (ZnO/PS). The ZnO nanoparticles were synthesized by coprecipitation method and further surface modified with Locust bean gum (LBG), a galactomannan polysaccharide. The LBG is known to reduce the Ag⁺ to Ag⁰, thus forming silver nanoparticles on the ZnO/PS. The synthesized ZnO and Ag@ZnO were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy (FTIR). The uniform distribution of fine spherical Ag NPs on the ZnO surface was seen under the SEM. The ZnO and Ag@ZnO NPs were evaluated for their catalytic activity towards the reduction of phenolic compounds. A significant enhancement in the catalytic power was seen with the deposition of Ag NPs on ZnO. Ag@ZnO exhibited strong antimicrobial activity towards both gram-positive and gram-negative bacteria with an inhibition zone of 18.30 ± 0.47 and 14.50 ± 0.50, respectively. Further, synthesized nanomaterials were explored for their application as a transducer material for the fabrication of electrochemical biosensor for the detection of E. coli. A linear sensing response was seen in the range of 2 to 10 CFU/ml bacterial concentration with a detection limit of 2 CFU/ml. Thus, the in-situ synthesis of Ag NPs on ZnO support using galactomannan as a reducing and stabilizing agent can significantly improve the catalytic, bactericidal and sensing characteristics of the nanomaterial.

Graphical abstract

Keywords: Ag@ZnO; Locust bean gum; Catalytic activity; Antimicrobial activity; Biosensing

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02848-7

Chemical Papers 77 (9) 5115–5128 (2023)