Pore Confinement-Enhanced Electrochemiluminescence on SnO2 Nanocrystal Xerogel with NO3- As Co-Reactant and Its Application in Facile and Sensitive Bioanalysis.

Herein, 10-fold electrochemiluminescence (ECL) enhancement from a porous SnO2 nanocrystal (SnO2 NC) xerogel (vs discrete SnO2 NCs) was first observed with NO3- as a novel coreactant. This new booster phenomenon caused by pore characteristic was defined as "pore confinement-induced ECL enhancement", which originated from two possible reasons: First, the SnO2 NC xerogel with hierarchically porous structure could not only localize massive luminophore near the electrode surface, more importantly, but could accelerate the electrochemical and chemiluminescence reaction efficiency because the pore channels of xerogel could promote the mass transport and electron transfer in the confined spaces. Second, the NO3- could be in situ reduced easily to the active nitrogen species by means of the pore confinement effect, which could be served as a new coreactant for nanocrystal-based ECL amplification with the excellent stability and good biocompatibility. As a proof of concept, a facile and sensitive sensing platform for SO32- detection has been successfully constructed upon effectively quenching of SO32- toward the SnO2 NC xerogel/NO3- ECL system. The key feature about this work presented a grand avenue to achieve the strong ECL signal, especially from weak emitters, which gave a fresh impetus to the construction of new-generation of surface-confined ECL platform with potential applications in ECL imaging and sensing.

Ultrasonic-Assisted Dispersion of ZnO Nanoparticles and Its Inhibition Activity to Trichoderma viride.

The activity inhibition of fungi by ZnO nanoparticles (NPs) has shown huge potential applications in the area of hygienic coatings. However, the inhibition efficiency was limited due to the agglomeration of NPs. To obtain well-dispersed and highly stabilized ZnO nanofluids, ZnO NPs were capped with four kinds of surfactants under ultrasonication. The capping procedure was optimized by varying the dosage of surfactants, the ultrasonic duration, ultrasonic power and temperature. Capped ZnO nanofluids were then used for the inhibition of Trichoderma viride. The influence on the activity of the capping conditions, illumination, ZnO NPs content, humidity and temperature were investigated in details. Results suggest that well-dispersed ZnO NPs were obtained through ultrasonic-assisted functionalization using sodium polyacrylate as a dispersant. Moreover, capped ZnO nanofluids revealed long-term stability at pH above 6. The optimal capping procedure was obtained for a sonication power of 250 W, treatment duration of 40 min, dosage of 0.4% and temperature of 60 °C. Antifungal tests indicated that capped ZnO NPs showed an inhibition ability versus T. viride even in the dark. The antifungal ability of ZnO NPs increased with the increasing ZnO content, and humidity and temperature only affected the growth of fungi. Capped ZnO NPs showed an excellent antifungal performance even in the circumstance that was beneficial for the fungi growth (temperature of 30 °C, humidity of 95%), demonstrating the antimicrobial capability in practical applications.