Antibacterial Properties of Silver Nanoparticle (AgNPs) on Stainless Steel 316L

Objective(s): In Indonesia, the incidence of bone injuries as a result of traffic accidents is quite high. This necessitates the use of bone implants, which are frequently made of Stainless Steel 316L ( SS316L). The probability of contracting an infection when implanting an SS316L implant has been increasing. Infection due to implant placement is called osteomyelitis which is bone inflammation caused by biofilms formed by pyogenic bacteria. Biofilms can be prevented by giving antibacterial agents. This research aims to explore silver nanoparticles (AgNPs) as an antibacterial agent in SS316L implants. Methods: AgNPs are synthesised using the Gallic acid reduction technique. AgNPs solution added with gelatin was misted on SS316L with five different precursor concentrations (0.1, 1, 10, and 100 mM) using the airbrush spray coating approach with a distance of 20 cm between the nozzle and the substrate and a pressure of 40 psi. Results: AgNPs solutions produced from various concentrations of AgNO3 precursors have a broad spectrum of excitation maximums (λmax = 401.5 nm- 424.5 nm) and crystallite size in the range of 0.97 - 4.88 nm. The AgNPs layer on SS316L was characterized for their crystalline phase, crystal size, and anti-bacterial activity. It has a cubic structure with a phase fraction of 6.5-19%. The inhibition zone radius for AgNPs coated samples is in the range of 12-16 mm. The combination coating of AgNPs (10 mM) and gelatin layer seemed to have the best antibacterial ability, with an inhibition zone diameter of 16.63 mm. Conclusions: It is imperative to generate concentration variation of the 10 mM AgNPs precursor - Gelatin to be used to as coating layer on the SS316L restorative surface.