UV/enzyme dual responsive photosensitizer‐loaded 4‐(Phenylazo)benzoic Acid‐mPEG nanosystem for enhanced photodynamic insecticide efficacy

Abstract

To improve photostability and enhance utilization rate and reduce pest resistance, a new strategy based on the combination of photodynamic insecticide action and stimulus‐responsive polymer micelles is developed. 4‐(phenylazo)benzoic acid (PBA)‐modified poly(ethylene glycol) monomethyl ether (mPEG) conjugate is prepared by the esterification reaction of mPEG and PBA, and followed by self‐assembly in aqueous solution to obtain polymeric nanoparticles. TEM shows that the nanoparticles have a core‐shell structure and an average diameter of 78 nm. DLS shows that the nanoparticles are stability in water solution but can change their structure in response to UV light and/or esterase stimulation. The photodegradation of Protoporphyrin IX (PpIX) encapsulated in the nanoparticles can be effectively inhibited because of aggregation‐caused quenching effect, whose maximum photodegradation rate is about 20.54% after 8 h exposure to daylight compared with the complete photodegradation of free PpIX. UV light and/or esterase stimulus can trigger PpIX release and result in a high photodynamic activity. Compared with free PpIX, the PpIX‐loaded nanoparticles show a higher phototoxicity to insect cells and the daylight pretreatment has little influence on the phototoxicity.

Light‐induced Photoswitching of 4‐(Phenylazo)benzoic Acid on Au(111)

“…The carboxylic group in PABA permits covalent bonding to various precursors via amide/ester linkage and ligand function through deprotonation. This allows its use in many photoisomerization studies requiring azobenzene functionality including, DNA photo‐regulation, [26] photosynthesizer activity, [27] photoluminescence, [28] smart micellar systems, [29] photoswitchable enzyme inhibitors [30] and supramolecular systems [31] . As such, a comprehensive understanding of its photoisomerization process is valuable for future applications in photoswitchable devices.…”

Electrically reading a light-driven molecular switch on 2D-Ti3C2Tx MXene via molecular engineering: towards responsive MXetronics

“…48 As shown in Fig. 1k, the two main absorption bands associated to the raw AZO molecule 49 —one in the ultraviolet region ( λ UV,max = 327 nm, high-intensity π–π* absorption) and another one in the visible region ( λ Vis,max = 441 nm, low-intensity n–π* absorption), see inset—were clearly blue-shifted to 278 nm ( λ UV,max ) and 430 nm ( λ Vis,max ) after being grafted to the MXene. This supposes an additional proof of the covalent nature of the anchoring.…”

A pectin-based photoactivated bactericide nanosystem for achieving an improved utilization rate, photostability and targeted delivery of hematoporphyrin

“…The latter could only penetrate inwards from the surface to the hydrophobic core, and then HP was gradually released from NPs through a diffusion mechanism. 43…”