Enhancing silver nanoparticle and antimicrobial efficacy by the exfoliated clay nanoplatelets

Abstract

The antimicrobial efficacy of silver nanoparticles (AgNP) is enhanced by using the exfoliated clay nanoscale silicate platelets (NSP) as the supports. The NSP were in the dimension of 80 nm × 80 nm × 1 nm and were derived from the exfoliation of natural clays such as sodium montmorillonite. Increasing the amount of NSP addition at the relative Ag/silicate composition ratios from 0.5/99.5 to 50/50 w/w significantly altered the particle size AgNP from 3.6 nm to 35 nm in diameter. Evaluation of antibacterial activities for these nanohybrids demonstrated the effect of the amount of NSP support and Ag size on inhibiting the growth of dermal pathogens including Gram-positive and Gram-negative bacteria. Scanning electron microscope observations further revealed the interaction of the AgNP/NSP nanohybrids in contact with individual bacteria surface. The tailoring of the AgNP/NSP nanostructures has largely affected the bacterial surface interaction by NSP adherence and hence the antimicrobial efficacy.