Green-monodispersed Pd-nanoparticles for improved mitigation of pathogens and environmental pollutant

Abstract

This research, for the first time, demonstrates the synthesis of a novel double chain amphiphilic metallosurfactant complex i.e., bisdecanoatopalladium (II) (complex 1) which provides a template to fabricate monodispersed palladium nanoparticles (Pd NPs). Complex 1 was characterized using CHN, Mass, NMR and FTIR techniques. Complex 1 formed inverted metallomicelles (IMMs) in various n-alcohols and DCM at very low critical aggregation concentration (CAC), (1.19–1.65 × 10−4 M) estimated using conductivity studies. IMMs-supported greener synthesis of Pd NPs suggests the localized and controlled reduction of metalloaggregates and arrested growth of Pd NPs confined in the cavity of IMMs. UV–vis, XRD, HRTEM and DLS techniques have provided a detailed insight into the structure, morphology and dispersibility of as-obtained Pd NPs. The uniform surfactant coating enables the synthesis of highly monodispersed and spherical Pd NPs in a very narrow size of 1–2 nm. This green approach eliminates the existing challenges of controlling size, shape, and dispersibility. The superiority of Pd NPs has been explored in terms of catalytic and biological applications. The Pd NPs are found to be extremely selective, efficient, and eco-friendly and recyclable catalysts for the reduction of para-nitrophenol (PNP) with an achievable rate constant as high as 1.018 min−1 with mere 2 mol% catalyst dose. Pd NPs also exhibit excellent binding ability with BSA protein exhibiting a high binding constant of 9.7 × 105 M−1. Besides, Pd NPs can be promoted as excellent therapeutic agents as they have shown noteworthy (i) antimicrobial activity against pathogenic microbes i.e., Bacillus cereus ITCC 240 (MIC 0.002 μg/mL), Klebsiella pneumoniae ITCC 138 (MIC 0.003 μg/mL) and Curvularia lunata ITCC 6257 (MIC 0.001 μg/mL) and (ii) anticancer activity against human liver cancer cells i.e., HepG2 (IC50 25 μg/mL). The outcomes of this research epitomize Pd NPs as a potential green nano-system having broader prospective in catalytic and biological applications.