RESUMO
A new method for the detection of ultra-low concentration of penicillin G (PG) antibiotic was innovated using gold nanoparticles/porous silicon (AuNPs/PSi) SERS active substrate. PSi was employed as a template and a reducing agent to deposited aggregated AuNPs with a high density of hot spot regions. A highly enhancement performance and reproducible AuNPs/PSi SERS substrate was fabricated. The AuNPs/PSi SERS substrate was investigated for detection PG drug at different concentrations ranging from 10-3 to 10-9â¯M. The results showed that the proposed AuNPs/PSi SERS substrate provide an efficient way for detection the lowest concentration of PG. The adsorption process of the PG drug on the surface of the AuNPs/PSi was investigated, it was found that PG was close to the surface of AuNPs/PSi through the carboxylate group. The enhancement factor (EF) of 5â¯×â¯107 and a 4.5% relative standard deviation of reproducibility were obtained at an ultra-low PG concentration of 10-9â¯M. The influence of the pH value on the EF for PG antibiotic under acidic and alkaline conditions (EFpH) was studied, it was shown that the highest EFpH with efficient activity toward PG was obtained at pHâ¯=â¯5.
