Multifunctional silver nanoparticles decorated N, S co-doped graphene as a sensitive colorimetric probe for L-cysteine detection and as an antibacterial agent

Abstract

The fabrication of structured nanocomposites possessing dual applications have always attracted great research attention, especially in the fields of biomolecule detection and as antibacterial agents. In the current study, silver nanoparticles grafted on N, S co-doped graphene (Ag-NSG) were synthesized using a simple and facile chemical reduction method. The synthesized nanocomposite was employed as a colorimetric probe for the detection of L-cysteine (L-cys) in chickpea (Cicer arietinum L.) and as an antibacterial agent against Gram-positive positive (S. aureus) and Gram-negative (E. coli) bacteria. Ag-NSG exhibited a highly cordant recovery of 98.4 % for the different chickpea samples, signifying an outstanding selectivity of the proposed probe towards the target analyte. The antibacterial investigation was carried out employing the agar well diffusion method, by measuring the zone of inhibition (ZOI), under different dosages of the synthesized nanocomposite. The zone of inhibitions increased with increasing concentrations and the highest zone obtained was 30.6 ± 1.2 mm for S. aureus and 25.3 ± 0.3 mm for E. coli.