Conjugated polymer materials for detection and discrimination of pathogenic microorganisms:Guarantee of biosafety

Infectious disease outbreaks have seriously endangered global health owing to the scarcity of testing materials and techniques.Diversified materials and methods should be urgently developed for rapid detection and discrimination of pathogenic microorganisms.Conjugated polymer(CP)materials are macromolecular compounds comprising numerous covalently bonded luminescent units.They have excellent light-harvesting and optical signal amplification capabilities owing to the transmission of excitation energy along their backbone.In recent years,CP materials have aroused research enthusiasm in the biosensors field because of their outstanding optoelectronic properties.This brief manuscript provides an overall review of recent progress achieved in CP-based systems for pathogen sensing.

An advanced 2D/3D g-C_(3)N_(4)/TiO_(2)@MnO_(2) multifunctional membrane for sunlight-driven sustainable water purification

Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane development.Here,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) nanosheets.The 3D flower-like nanostructures broaden the transport channels of the composite membrane.The membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic capabilities.The remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.

Pyrenoviologen-based fluorescent sensor for detection of picric acid in aqueous solution

Two highly emissive pyrenoviologen derivatives were synthesized and used to fabricate fluorescent sensors for detection of picric acid(PA)with good sensitivity and selectivity.The sensitivity of the sensor was attributed to the specific electrostatic association effect of the cationic pyrenoviologens to the picrate anions,which also gave the sensor special selectivity among other compounds with similar structure.The electron transfer between them was attributed to the fluorescence response.Fluorescence lifetime measurements revealed that the quenching is static in nature.The novel and efficient pyrenoviologen derivatives-based sensors offered a strategy to fabricate real-life PA sensor.

Supramolecular fabrication of hyperbranched polyethyleneimine toward nanofiltration membrane for efficient wastewater purification

Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation membranes owing to its superiority.Here,we prepared a hyperbranched PEI-based separation mem-brane through the supramolecular hydrogen bond interaction for wastewater purification.The amino groups in the PEI molecule were partially oxidized to the nitro groups with sodium hypochlorite(NaClO).Moreover,the PEI molecu-lar chains can be regulated from the hyperbranched state to the internal nucle-ation state.Molecular dynamics simulation results further indicated the strong hydrogen bonds among the oxidized PEI(O-PEI)molecular chains and the decreased gyration radius of the O-PEI molecule due to the formation of the nitro groups.In addition,the wettability and zeta potential of O-PEI membranes can be controlled by adjusting the molecular weight and oxidation degree of the PEI molecules.Under the collective effect of size screening and charge repulsion,the O-PEI separation membrane displayed a wide range of purification capabilities for contaminations,such as dye molecules and salts.This work may offer a new strategy to fabricate hyperbranched O-PEI membranes for wastewater purifica-tion.