Selective and sensitive colorimetric detection of platinum using Pseudomonas stutzeri mediated optimally synthesized...

In this work, Pseudomonas stutzeri was used for the optimum biogenic synthesis of antibacterial silver nanoparticles (AgNPs) which were applied for colorimetric detection of platinum ions (Pt⁺²). The optimum synthesis conditions were 2 mM AgNO_3, pH 9 and incubation at 60 °C for 24 h. The FTIR spectra indicated that biomolecules such as amino acids, proteins or enzymes from P. stutzeri were involved in the synthesis of AgNPs in the size range of 10-50 nm. Among the various metal ions tested and screened initially, the colloidal AgNPs probe-based colorimetric assay selectively detected Pt⁺² with 50 ppm as the limit of detection (LOD). The assay demonstrated in the present study quantitatively recovered Pt⁺² in the range of 70-150 % with good accuracy and precision. Further, the test of antibacterial activity of AgNPs alone, and in combination with ampicillin showed excellent activity against four of the six tested bacteria.