Optical nanothermometers have attracted much attention due to their non-contact and precise measurement with high spatial resolution at the micro- and nanoscales. They can be applied in various fields such as micro-opto-electronics, photonics, and biomedical thermal and pH sensing, while most thermal sensors reported so far contain heavy metals or have low sensitivity. Herein, we demonstrate a highly sensitive ratiometric thermal sensor based on colloidal C-dots. C-dots exhibit dual emission originating from the band gap emission and surface-dominant emission, which show a different temperature-dependent photoluminescence (PL) response. Among different surface-functionalized C-dots, C-dots@OH exhibit an absolute thermal sensitivity of −0.082 °C⁻¹, which is the highest among various types of ratiometric thermosensors, making it a very promising candidate for high-sensitivity, self-calibrated nanoscale thermometry. As a proof-of-concept, C-dots@OH were employed to monitor the intracellular temperature (32–42 °C), showing a clear trend for temperature variation in a single cell, indicating that C-dots could offer a powerful tool for a potential precise measurement of the intracellular temperature. They could also be used as thermal sensors for nano-electronic and optoelectronic devices.

Pine wilt disease (PWD), a destructive disease for pine trees, is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z. marina through solvent extraction, followed by chromatography on AB-8 resin and crystallization. The NMR and HPLC analysis showed that the isolated compound was rosmarinic acid (RosA). RosA showed effective nematicidal activity, of which the LC₅₀ (50% lethal concentration) to PWN at 24 h, 48 h and 72 h was 1.18 mg/g, 1.05 mg/g and 0.95 mg/g, respectively. To get a high yield rate of RosA from Z. marina, single factor experiments and an L₉ (3⁴) orthogonal experiment were performed. This extraction process involved 70% ethanol for 3 h at 40 °C. The extraction dosage was 1:50 (w/v). The highest yield of RosA from Zostera was 3.13 mg/g DW (dried weight). The crude extracts of Zostera marina (10 mg/mL) and RosA (1 mg/mL) also showed inhibitory effects to some bacterial strains carried by PWN: Klebsiella sp., Stenotrophomonas maltophilia, Streptomyces sp. and Pantoea agglomerans. The results of these studies provide clues for preparing pesticide to control PWD from Z. marina.

MoO_x QDs were prepared using a one-step stirring treatment of MoO₃ powder in DMSO. They can be used as efficient fluorescent probes and antibacterial materials.

The ethanol extract of the Ficus carica L. leaves was tested to show strong nematicidal activity against pine wood nematode (PWN), Bursaphelenchus xylophilus, causing 90.93% corrected mortality within 72 h at 1.0 mg/mL. From the ethyl acetate soluble fraction of the F. carica L. leaves extract, the main nematicidal constituents were obtained by bioassay-guided isolation and identified as linear furocoumarins bergapten (1) and psoralen (2) by mass and NMR spectral data analysis. Bergapten and psoralen had significant nematicidal activity against PWN with the LC₅₀ values of 97.08 aKSnd 115.03 μg/mL within 72 h, respectively. The two furocoumarins could inhibit the activities of amylase, cellulase and acetylcholinesterase (AchE) from PWN. The morphologies of PWNs changed much after they were treated by bergapten and psoralen. The physiological effects of bergapten and psoralen on PWN might provide helpful clues to elucidate their nematicidal mechanisms. Graphical abstract