Phosphorous and nitrogen co-doped carbon dots (P,N-CD) with satisfactory quantum yield have been prepared through one-step acidic oxidation of pumpkin by H 3 PO 4 at low temperature (90 o C). The asprepared P,N-CD is relatively monodisperse with a narrow size distribution. The P,N-CD displays a remarkable emission enhancement in the yellow fluorescence region (λ em = 550 nm) when the pH is 10 increased from 1.5 to 7.4. The pK a of P,N-CD was found to be 4.17 and it shows linear response to physiological range of pH 4.7-7.4, which is valuable for near-neutral cytosolic pH research. It is observed that P,N-CD is a superior fluorescent bioimaging agent in animals and cells thanks to its excellent solubility and ultra-low toxicity. In addition, P,N-CD displays a notably large Stokes shift of 125 nm, good reversibility and could effectively avoid the influence of autofluorescence in biological systems. 15 The confocal fluorescent microscopic images of subcellular distribution and the detection of pH in MCF-7 cells were achieved successfully, suggesting that P,N-CD has excellent cell membrane permeability and is further applied successfully to monitor pH fluctuations in live cells with negligible autofluorescence. 65 Recently, there has been a trend to synthesise doped CD from natural biomass as they are inexpensive, inexhaustible and nontoxic. Several successful demonstrations were given to prepare nanomaterials using biomass materials which had many potential applications. 7,[42][43][44] We are interested in developing 70 convenient ways to synthesise P,N-CD from environmentally friendly materials and simple apparatus. As we all know, pumpkin abounds with carbon, nitrogen, oxygen, phosphorus, sulfur, and hydrogen elements owing to the existence of carbohydrate, protein, lipid, and glutathione. Thus, we anticipate 75 that this natural material should be a promising precursor for

A novel ratiometric emission fluorescent probe, 1,1-dimethyl-2-[2-(quinolin-4-yl)vinyl]-1H-benzo[e]indole (QVBI), is facilely synthesized via ethylene bridging of benzoindole and quinoline. The probe exhibits ratiometric fluorescence emission (F(522nm)/F(630nm)) characteristics with pKa 3.27 and linear response to extreme-acidity range of 3.8-2.0. Also, its high fluorescence quantum yield (Φ = 0.89) and large Stokes shift (110 nm) are favorable. Moreover, QVBI possesses highly selective response to H(+) over metal ions and some bioactive molecules, good photostability, and excellent reversibility. The probe has excellent cell membrane permeability and is further applied successfully to monitor pH fluctuations in live cells and imaging extreme acidity in Escherichia coli cells without influence of autofluorescence and native cellular species in biological systems.

A novel fluorescent probe based on N,S,P codoped carbon nanodots (N,S,P-CND) is very simple and quickly fabricated by a one-step hydrothermal pyrolysis of Saccharomyces cerevisiae and utilized for label-free and "on-off-on" sequential detection of manganese(VII) and l-ascorbic acid (l-AA). The fluorescence of N,S,P-CND can be effectively quenched by Mn(VII) based on an inner filter effect (IFE) and recovered upon the addition of l-AA due to the easy conversion of Mn(VII) to reduced states (i.e., Mn(IV), Mn(II), and Mn(0)) by l-AA. This probe exhibited favorable selectivity and sensitivity toward Mn(VII) and l-AA with detection limits of 50 nmol/L and 1.2 μmol/L, respectively. Simultaneously, an "AND" logic gate based on the as-fabricated N,S,P-CND has been constructed. Also, the as-proposed fluorescent probe was extended to detect Mn(VII) and l-AA in biosystems. Furthermore, the as-constructed fluorescent probe system was successfully applied to the analyses of Mn(VII) in tap water, Fenhe River water, and medicinal herb samples with satisfactory results. The proposed method is simple and easily accessible, demonstrating the great potential of N,S,P-CND in biosensing, disease diagnosis, cellular labeling, and environmental monitoring.

BackgroundThe microRNA miR-101 is downregulated in several cancers, including bladder cancer. However, miR-101’s role in the invasion, metastasis, and chemosensitivity of bladder cancer cells remains unclear. This study was conducted to determine miR-101’s role on the lymphangiogenic molecule vascular endothelial growth factor C (VEGF-C) and their effects upon bladder cancer cell migration, invasion, and chemosensitivity to cisplatin.MethodsTwo bladder cancer cell lines (T24 and 5637) and the tool cell line 293T were employed here. Bladder cancer cells were transfected with either a miR-101 overexpression vector or a scrambled-sequence lentivirus, both of which exhibited a high transfection efficiency. Non-transfection was used as a mock negative control. Wound healing and Transwell assays were performed to measure cell migration and invasiveness. A luciferase reporter assay was performed to validate miR-101’s interaction with VEGF-C’s 3′ untranslated region followed by RT-PCR and Western blot confirmation. An MTS assay was used to evaluate the cisplatin sensitivity of the cell lines.ResultsmiR-101 overexpression significantly inhibited the migration and invasiveness while significantly enhancing cisplatin sensitivity. miR-101 negatively regulated VEGF-C protein expression, and VEGF-C overexpression rescued the effects of miR-101 overexpression, indicating that miR-101 negatively regulates VEGF-C protein expression post-transcriptionally. miR-101 and VEGF-C interference independently enhanced cisplatin cytotoxicity in bladder cancer cells.ConclusionsmiR-101 suppresses VEGF-C expression, inhibits cell migration and invasion, and increases cisplatin sensitivity in bladder cancer cells. This study provides new insight into miR-101’s role in bladder cancer and shows miR-101’s promise as a potential molecular target for bladder cancer.

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A facile, economical and green one-step hydrothermal method for N-doped CDs was presented by using citric acid as carbon source and urea as nitrogen source. The fluorescence of N-doped CDs quenched dramatically from curcumin via inner filter effect.

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