A new 1,8-naphthalimide derivative (NAD) was synthesized and employed as a highly sensitive and selective probe for the detection of cysteine (Cys) and Cu2+. The terminal olefin of NAD could react with Cys and resulting in fluorescence quenching, with the adding of Cu2+, the schiff base unit of NAD could coordinate with Cu2+ and lead to a highly selective fluorescence “turn-on” response. The detection limits reached as low as 25 nM for Cys and 11 nM for Cu2+. In addition, the NAD probe can be further applied to cells imaging owing to its photostability and low cytotoxicity.1,8-naphthalimide derivative (NAD) was developed for highly sensitive and selective detection of Cys and Cu2+ with the detection limits as 25 nM for Cys and 11 nM Cu2+. In addition, the NAD probe can be further applied to cell imaging owing to its photostability and low cytotoxicity.

•A novel turn-on NIR fluorescent probe for Cys was developed.•The probe can detect Cys with high selectivity and sensitivity in aqueous solution.•The detect limitation of Cys is down to 0.16 μM.•This probe can be a useful tool for the selective detection of Cys in living cells.The near-infrared (NIR) fluorescent probe for rapid, highly sensitive and selective detection of cysteine (Cys) has great significance in both biological and environment sciences. In this work, a novel and specific dicyanoisophorone-based NIR probe for Cys was developed. This probe features remarkably large Stokes shift, with turn-on fluorescence property for highly sensitive and selective detection of Cys over other amino acids including the similar structured homocysteine (Hcy) and glutathione (GSH). The probe based on the conjugate addition-cyclization reaction, and has low detection limit of Cys. Furthermore, this probe shows great potential for Cys detection, which was successfully applied to bioimage Cys in living cells with low cytotoxicity.A novel turn-on near-infrared fluorescent probe for detection of Cys with high selectivity and sensitivity and its bioimaging application in living was first proposed.Download high-res image (63KB)Download full-size image

Hyperbranched aromatic-aliphatic polyester HBPE-BBA was synthesized by modifying the periphery of a second-generation hyperbranched polyester (HBPE) with benzimidazole (BBA) end groups. HBPE-BBA showed interesting self-assembly behaviors, and retained one-dimensional nano bead-on-string fibers and two-dimensional helical nanocoil morphologies in different solvents. The fluorescence results indicated that HBPE-BBA exhibited remarkable selectivity for Fe3+ and fused ring compounds.

This paper developed a new fluorescent rhodamine-based derivatives (RAD) probe for highly sensitive and selective detection of Cu2+ and L-Methionine (L-Met). The detection limits can reach as low as 12 nM for Cu2+ and 5 nM for L-Met, In addition, the RAD probe can be further applied to cell imaging owing to its photostability and low cytotoxicity.A new fluorescent rhodamine-based derivatives (RAD) probe for highly sensitive and selective detection of Cu2+ and L-Methionine (L-Met) was developed with the detection limits can reach as low as 12 nM for Cu2+ and 5 nM for L-Met, In addition, the RAD probe can be further applied to cell imaging owing to its photostability and low cytotoxicity.

The structurally controllable hyperbranched HBPE–CIDAs (HBPE modified with CIDA units) were synthesized by modifying the periphery of the second generation hyperbranched polyester (HBPE) with 1-cyanoindolizine-3-carboxylic acid (CIDA) groups via a one-pot synthesis. The structures and self-assembly behaviors of HBPE–CIDAs were established by combined studies of FFT-IR, NMR, TEM, SEM, AFM and XRD. Furthermore, host–guest recognition of HBPE–CIDAs was investigated by fluorescence studies. The results indicated that the HBPE–CIDA4 nanospindles have weaker response to various metal ions while having better selectivity to anthracene through π–π stacking interactions than the HBPE–CIDA1 nanospheres.

•A new N-doped carbon quantum dots (NCDs) was synthesized via one-step hydrothermal method using isoleucine and citric acid as carbon precursor.•NCDs exhibit highly sensitive fluorescence ‘turn-off’ response toward Fe3+ in aqueous solution.•The mechanism of the quenching process has been discussed.In this study, new carbon nanomaterial N-doped carbon dots (NCDs) were obtained via a one-step hydrothermal method using isoleucine and citric acid as carbon precursors. TEM results showed that the NCD diameters were not uniform but distributed in the 6–15 nm range, with an average value of 10 nm. The maximum emission wavelength of the obtained NCDs was 415 nm with an excitation wavelength of 370 nm. Under optimal conditions, the nanoparticle can be used as sensors and exhibited a ‘turn-off’ fluorescence response to Fe3+, with a good linear relationship of (F/F0) versus Fe3+ over the concentration range of 0–20 μmol/L.

In this study, two water-soluble fluorescent probes based on pyrrolo[2,1-a]isoquinoline derivatives (4a and 4b) were synthesized and characterized by IR, 1H NMR, 13C NMR, MS spectra and elemental analysis for the first time. The obtained compounds (4a and 4b) showed fluorescent ‘turn-on’ phenomenon to Ag+ with limits of detection (LOD) of 0.6 μM (4a) and 0.8 μM (4b) (S/N=3), respectively.

Herein, we reported the synthesis of hyperbranched aromatic–aliphatic co-polyester nanorods HBPE-CICA6 and HBPE-CICA2 by modifying the periphery of second generation hyperbranched polyester (HBPE) with 1-cyano-pyrrolo[2,1-a]isoquinoline-3-carboxylic acid (CICA) groups. Structures of the HBPE-CICAs were confirmed by combined studies of Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The potential application of HBPE-CICAs in ion recognition was investigated; in particular, HBPE-CICA2 exhibited remarkable selectivity for Fe3+.

Some new 4H-pyrrolo[1,2-a]benzimidazoles(2a–2f) have been synthesized. The structures of these compounds were confirmed by IR, 1H NMR, mass spectroscopy and elemental analysis. Compound 2a was further confirmed by X-ray diffraction. The in vitro antimicrobial activities of these compounds were determined against some gram-positive bacteria, gram-negative bacteria and fungi and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicate that compounds 2c, 2d and 2e show moderately active antibacterial properties, their minimum inhibitory concentrations are from 12.5 μg/mL to 125 μg/mL. In the series, the most active compound against C. albicans is compound 2f with an MIC value of 31.25 μg/mL.

•Hydroxyl-capped phosphorylcholines with different carbon spacer lengths were synthesized.•HOPC was tethered onto cellulose surface with HDI in inverse PC form (CP form).•HOPC grafted cellulose exhibited good hemocompatibility and antifouling property.Tethering of biomimetic phosphorylcholine derivative onto the surface of biomedical devices is an effective method for improving hemocompatibility and antibiofouling property. Herein, series of novel hydroxyl-capped phosphorylcholines (HOPC) with different carbon spacer lengths were first synthesized and characterized with element analysis (EA), Fourier transform infrared spectroscopy(FTIR), and nuclear magnetic resonance spectroscopy (NMR). Then, HOPC (n = 5, 2a) was one-pot tethered onto cellulose membrane with hexamethylene diisocyanate (HDI) as a coupling agent. The existence of phosphorylcholine was demonstrated by water contact angle measurement, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The hemocompatibility and antibiofouling property were evaluated by hemolytic test, platelet adhesion, protein adsorption, and Escherichia coli adhesion test. The results showed that cellulose membranes tethered with HOPC exhibited excellent hemocompatibility featured by low platelet adhesion and fibrinogen adsorption as well as antibiofouling property with bacterial adhesion resistance.