Synergistic Enhancing of Biological Activity and Natural Light Self-Degradation of Organic–Inorganic Hybrid Nano-organometallic Pesticide-Fused Phenylpyrazole Amine Derivatives with Hollow Box TiO2 by One-pot Microwave Synthesis

Nano-TiO2 as an antimicrobial inorganic material, can stimulate cells to produce reactive oxygen species and exhibit effective biochemical properties; however, phenylpyrazole derivatives, as organic pesticides, are widely used in agriculture and food. To find novel pesticides with environmental friendliness, combined with three-dimensional quantitative structure-activity relationship (3D-QSAR) prediction analysis, three types of alkaloidal phenylpyrazole amine derivatives (PA) were synthesized by a one-pot microwave method. Based on the dye sensitization strategy, four nano-organometallic pesticides (PT) were prepared by organic-inorganic hybridization. PA and PT showed 2.5 and 5.2 times higher insecticidal activity against P. xylostella than fipronil, and PT had 3.9 times greater antibacterial activity against A. tumefaciens. The synergistic effect realizes the balance of amphiphilicity, enhances the biological activity of PT, improves the phloem fluidity, and promotes the absorption and transportation of substances. In addition, this synergistic effect reduces the band gap width, improves the light absorption capacity, induces cells to produce active reactive oxygen species and free radicals (ROS: ·O2-, ·OH), and destroys the cytomembrane so that PT can better enter the cell, resulting in cell death. PT has excellent natural light self-degradation performance and converts to the phenylpyrazole parent moiety, which enhances biological activity and greatly reduces the environmental residues, implying that nano-organometallic pesticide (PT) provides a new idea for its natural degradation and fluorescence detection of pesticide residues.