Bacterial infections present a significant threat to human health, a challenge that is intensified by the slow pace of novel antibiotic development and the swift emergence of bacterial resistance. The development of novel antibacterial agents is crucial. Indocyanine green (ICG), a widely used imaging dye, efficiently generates reactive oxygen species (ROS) and heat for treating bacterial infections but suffers from aggregation and instability, limiting its efficacy. In this study, tungsten disulfide (WS₂) nanosheet with a high surface area was used to load ICG, creating a multifunctional nanocomposite, WS 2 /ICG, aimed at treating bacteria-infected wounds. The two-dimensional surface structure of WS₂ provides dispersible binding sites for ICG, and the synthesized nanocomposite exhibits excellent stability. Under near-infrared (NIR) laser excitation, the generated heat further synergistically enhances the yield of singlet oxygen. Additionally, the WS₂/ICG nanoplatform synergistically combines photothermal effect with photodynamic effect, achieving a “1 + 1 > 2” enhancement. Upon NIR laser excitation, the nanocomposite disrupts bacterial cell membranes through localized heating and ROS accumulation, leading to energy metabolism system disruption and subsequent bacterial lysis and death. The findings demonstrate WS₂/ICG's outstanding antibacterial properties and biocompatibility, effectively treating skin infections and promoting tissue regeneration, providing a simple and promising solution for bacteria-infected wounds.
Jia Ge,Xin-Geng,Ya-Hui Du,Jia-Jia Chen,Lin Zhang,Dong-Mei Bai,Dan-Yang Ji,Ya-Lei Hu,Zhao-Hui Li
In this work, a simple and signal-on assay has been developed for highly sensitive and selective detection of mercury ion (Hg 2+ ) based on the WS 2 nanosheets and T7 exonuclease-assisted cyclic signal amplification. WS 2 nanosheet exhibits differential affinity toward short oligonucleotide fragment versus single-stranded DNA (ssDNA) probe, which is used as an adsorption material for capturing ssDNA and an efficient fluorescence quencher for reducing the background signal. T7 exonuclease, a sequence independent nuclease, catalyzes the removal of 5′ mononucleotides from the 5′ termini of double stranded DNA, while its activity on ssDNA is limited. Without Hg 2+ , FAM-labelled ssDNA probe and target probe are adsorbed by the WS 2 nanosheet and the fluorescence of FAM-labelled signal probe is quenched. In the presence of Hg 2+ , a FAM-labelled ssDNA probe could hybridize with the target probe to form duplex structures with a blunt 5′-terminal of signal probe through the formation of T-Hg 2+ -T base pairing. The FAM-labelled signal probe with a blunt 5′-terminal in the formed duplex can be digested by T7 exonuclease in the direction from 5′ to 3′, liberating the FAM fluorophore and releasing the Hg 2+ . The released target Hg 2+ and the remaining probe then bind another FAM-labelled ssDNA, and initiate the next round of cleavage, resulting in the release of numerous FAM labels back into the solution and significantly amplified fluorescent signal. This approach can warrant the detection limit for Hg 2+ down to 0.1 nM (S/N = 3) with high selectivity against other metal ions. Moreover, the application of the sensor for lake water shows that the proposed method works well for real samples. This research demonstrates an alternative approach to detect targets of interest that holds high prospects for detecting other biomolecules or metal ions in the near future.
危险品化学品经营许可证（带存储）