Rapid identification of volatile organic compounds and their isomers in the atmosphere

Isomers are widely present in volatile organic compounds(VOCs),and it is a tremendous challenge to rapidly distinguish the isomers of VOCs in the atmosphere.In this work,laserinduced breakdown spectroscopy(LIBS)technology was developed to online distinguish VOCs and their isomers in the air.First,LIBS was used to directly detect halogenated hydrocarbons(a typical class of VOCs)and the characteristic peaks of the related halogens were observed in the LIBS spectra.Then,comparing the LIBS spectra of various samples,it was found that for VOCs with different molecular formulas,although the spectra are completely the same in elemental composition,there are still significant differences in the relative intensity of the spectral lines and other information.Finally,in light of the shortcomings of traditional LIBS technology in identifying isomers,machine learning algorithms were introduced to develop the LIBS technique to identify the isomers of atmospheric VOCs,and the recognition results were very good.It is proved that LIBS combined with machine learning algorithms is promising for online traceability of VOCs in the atmospheric environment.

Review:Aggregation-Induced Emission——A New Tool to Study Polymer Thermodynamics and Kinetics

Polymer thermodynamics and kinetics are important components in the basic theory of polymer physics, which provide critical support for polymer processing and molding. As an important thermal analysis technology, differential scanning calorimetry(DSC) is a key way to explore the molecular motion of polymer chains, molecular structure, and condensed structure, greatly promoting the development of polymer materials. However, this technique is limited by its ambiguous results, because of inaccurate heat flow measurement and high parameter dependence. As an alternative strategy, aggregation-induced emission luminogens(AIEgens) have been extensively applied in various targets analysis and process monitoring, owing to their weak intermolecular interactions and highly twisted conformation. The optical properties of AIEgens are highly sensitive to the variations of the polymer microenvironment, including characteristic transition, crosslinking reaction, crystallization behavior, and phase separation. In this review, the progress of AIE technology in visualizing polymer molecular motion and structure evolution is summarized, compensating for the limitation of the traditional DSC method to facilitate further research in polymer science and engineering.

Confinement fluorescence effect of an aggregation-induced emission luminogen in crystalline polymer

Despite the impressive progress of stimuli-responsive fluorescent materials,little is known about the influence of confinement created by crystalline polymer over the fluorescence properties of fluorescent molecules.The effects of confinement on the fluorescence of an aggregation-induced emission luminogen(AIEgen)are investigated using computational simulations,which reveal that the confined space induces the AIEgens to take a more planar conformation,resulting in a red-shifted emission spectrum.With this property,the study is extended to explore the confinement generated by various polymer crystalline forms,and it is shown that different fluorescence colors are activated.This confinement fluorescence effect is attributed to the different spatial dimensions of the polymer amorphous layer between lamellar crystals where the AIEgens are located.These results indicate the immediate association between crystalline structure and fluorescence signals,activating unprecedented photophysical properties of luminescent materials,and also providing the possibility for crystalline structure visualization,it is important for the many polymer crystallization processes occurring in the materials processing.

Polydopamine/poly(sulfobetaine methacrylate)Co-deposition coatings triggered by CuSO_(4)/H_(2)O_(2)on implants for improved surface hemocompatibility and antibacterial activity

Implanted biomaterials such as medical catheters are prone to be adhered by proteins,platelets and bacteria due to their surface hydrophobicity characteristics,and then induce related infections and thrombosis.Hence,the development of a versatile strategy to endow surfaces with antibacterial and antifouling functions is particularly significant for blood-contacting materials.In this work,CuSO_(4)/H_(2)O_(2)was used to trigger polydopamine(PDA)and poly-(sulfobetaine methacrylate)(PSBMA)co-deposition process to endow polyurethane(PU)antibacterial and antifouling surface(PU/PDA(Cu)/PSBMA).The zwitterions contained in the PU/PDA(Cu)/PSBMA coating can significantly improve surface wettability to reduce protein adsorption,thereby improving its blood compatibility.In addition,the copper ions released from the metal-phenolic networks(MPNs)imparted them more than 90%antibacterial activity against E.coli and S.aureus.Notably,PU/PDA(Cu)/PSBMA also exhibits excellent performance in vivo mouse catheter-related infections models.Thus,the PU/PDA(Cu)/PSBMA has great application potential for developing multifunctional surface coatings for blood-contacting materials so as to improve antibacterial and anticoagulant properties.

Cyanobacteria-based self-oxygenated photodynamic therapy for anaerobic infection treatment and tissue repair

Photodynamic therapy(PDT)is an important technique to deal with drug-resistant bacterial infections in the post-antibiotic era.However,the hypoxic environment in intractable infections such as refractory keratitis and periodontitis,makes PDT more difficult.In this work,spontaneous oxygen-producing cyanobacteria were used as the carrier of photosensitizer(Ce6),and ultrasmall Cu_(5.4)O nanoparticles(Cu_(5.4)O USNPs)with catalase activity for infection and inflammation elimination and rapid tissue repair(CeCycn-Cu_(5.4)O).The loading of Ce6 and Cu_(5.4)O USNPs onto cyanobacteria surface were confirmed by transmission electron microscopy,nano particle size analyzer,scanning electron microscopy.In vitro sterilization and biofilm removal experiments demonstrated that the restriction of hypoxic environment to PDT was significantly alleviated due to the oxygen production of cyanobacteria.Under laser irradiation,the close transfer of energy photons to oxygen produced by cyanobacteria reduced more than 90% of Ce6 dosages(660 nm,200 mW/cm^(2),2 min).It is worth mentioning that both rapid sterilization through PDT and long-term oxidized free radicals elimination were achieved by adjusting the ratio of Ce6 and Cu_(5.4)O USNPs.Both periodontitis and refractory keratitis animal models proved the excellent self-oxygenation enhanced antibacterial property and promotion of tissue repair.

Corrigendum to“Polydopamine/poly(sulfobetaine methacrylate)Co-deposition coatings triggered by CuSO4/H2O2 on implants for improved surface hemocompatibility and antibacterial activity”[Bioactive materials 6(2021)2546-2556]

The authors regret to inform that Fig.3f is incorrect in the original article.A part of images of platelet adhesion on the PU and PU/PDA seemed to be duplicated with that on PU/PDA(Cu)/PSBMA surface.The authors had checked the original images and found the images were mistakenly taken from the same sample of PU/PDA(Cu)/PSBMA with continuous imaging.This correction does not change any description,results or conclusions of the original paper.