Plasmon-Assisted Enhancement of the Ultraweak Chemiluminescence Using Cu/Ni Metal Nanoparticles

Cu/Ni nanoparticles (NPs) with stable fluorescence and excellent water dispersion were synthesized through a facile aqueous solution method with a similar Kirkendall effect. Ultraweak chemiluminescence (CL) from the oxidation reaction between sodium hydrogen carbonate (NaHCO₃) and hydrogen peroxide (H₂O₂) in neutral medium was significantly enhanced by 60 ± 5 nm Cu/Ni NP with a copper and nickel molar ratio of 1:2. The enhancement of the time-dependent CL was dependent on the composition of the NP and the order of reagent addition. On the basis of studies of CL emission spectra, electron spin resonance spectra, UV–vis absorption, and fluorescence spectra, a mechanism of plasmon-assisted metal catalytic effect for this metal NP (MNP)-enhanced CL was proposed. The surface plasmons of MNP can obtain energy from chemical reaction, forming the activated MNP (MNP*), which was coupled to ·OH radical to produce the new adduct ·OH-MNP*. The ·OH-MNP* can accelerate the reaction rate of HCO₃^– for the generation of emitter intermediate (CO₂)₂*, which can lead the enhanced CL for the overall reaction

Antiviral Activity of Phenolic Derivatives in Pyroligneous Acid from Hardwood, Softwood, and Bamboo

Pyroligneous acids (PA) from hardwood, softwood, and bamboo significantly disinfected encephalomyocarditis virus (EMCV). Twenty-five kinds of phenolic derivatives in the PAs were identified and quantified. The total amounts of phenolic compounds in bamboo PA is higher than those in the PAs from softwood and hardwood. Phenol, 2-methoxyphenol, 2-methoxy-4-methylphenol, and 2-methoxy-4-ethylphenol are the most abundant compounds in the PAs examined. The activities of all the phenolic compounds against the encephalomyocarditis virus were assessed. The number of phenolic hydroxyl groups significantly affects the antiviral activity, and catechol and its derivatives exhibit higher viral inhibition effects than other phenolic derivatives. In addition, substituents affect the antiviral activity of the compounds. Phenolic compounds with a methyl group show higher activities than with a methoxyl group (e.g., 2-methylphenol > 2-methoxyphenol). Moreover, the relative position of functional groups also plays a key role in the viral inhibition activity (e.g., 2,6-dimethoxyphenol > 3,4-dimethoxyphenol). Thus, PAs contain phenol derivatives with considerable structural diversity and viral inhibition activities, providing a new strategy for virus-inactivation treatment through the optimization of PA-derived phenol structures