Graphene Oxide Quantum Dots Enhance Highly Efficient Pyrene Degradation by Shinella sp. B6

Abstract

Bacteria play a crucial role in degrading pyrene in various environments; however, challenges such as selective proliferation and low efficiency hinder their practical applications. To address these limitations, this study investigated the effect of graphene oxide quantum dots (GOQDs) on Shinella sp. B6, a bacterium capable of metabolizing various exogenous aromatic compounds as carbon sources. GOQDs exhibited superior biocompatibility with Shinella sp. B6, increasing culture's optical density at 600 nm (OD₆₀₀) from 0.027 to 0.364, and achieving a 73.5% degradation rate of pyrene in 60 h, a 3.73-fold improvement in efficiency compared with the single bacterium. GOQDs autonomously identified bacteria, leading to fluorescence quenching and subsequent recovery post-degradation. The disappearance of the infrared spectral peak of GOQDs, along with reductions in the ultraviolet absorption of pyrene, indirect antennae and confocal laser scanning fluorescence microscopy, confirms that GOQDs enhanced both biocompatibility and pyrene degradation efficiency. These findings enhance understanding of the interactions among quantum dots, organic pollutants, and degrading bacteria while offering insights for effective strategies to remove polycyclic aromatic hydrocarbon pollutants using bacteria augmented with quantum dot materials.