A tri-fluid tortuous microfluidic chip for green synthesis of nanoparticles and inactivation of a model gram-negative bacteria: Intracellular components evaluation

The development of green synthesis route using plant extract as a simple, cost-effective, and eco-friendly method for the synthesis of nanoparticles has become a major focus of researchers in recent years. In the present study, a novel continuous tri-fluid tortuous microfluidic chip (CTTM) was constructed to induce simultaneous mixing, Dean vortices, tortuosity, and repetitive bending in fluid behavior in order to plant-mediated synthesis of zinc selenide (ZnSe) nanoparticles. Additionally, the anti-pathogenic activity of nanoparticles against a human pathogen (E. coli) through the disruption of the cell membrane and the evaluation of the subsequent flow of cellular components such as continuous leakages of K⁺, nucleic acid, and intracellular protein was examined using the proposed chip. According to the results, by changing the flow rates up to 1.50 mL/min, nanoparticles with narrow size distribution were obtained. It was found that the nanoparticles sterilization effect in the case of α (V_{nanoparticles}/V_{bacteria strain}) =2 was obviously better than α = 0.5 under similar concentration and culture conditions. In this case, when the residence time and nanoparticle concentration tended to the maximum values, the release of intracellular components increased. Light microscopy and SEM clearly confirmed the ability of the antibacterial effects of nanoparticles to disrupt the bacteria membrane. Moreover, the inhibitory activity of the fabricated nanoparticles through a protein denaturation test using human serum albumin (HSA) showed an acceptable ability to inhibit protein denaturation compared to the inhibition of diclofenac sodium as a standard anti-inflammatory drug at the same concentration.