Nanozymes are potential candidates for constructing sensors due to their adjustable activity, high stability, and high cost-effectiveness. However, due to the lack of reasonable means, designing and preparing efficient nanozymes remains challenging. Herein, inspired by the property of natural laccase, we applied the novel and facile low-temperature plasma (LTP) technology to fabricate a series of different base-ligand Cu metal organic framework (MOF) nanozymes (namely, A-Cu, G-Cu, C-Cu and T-Cu nanozymes) with laccase-like activity successfully. Owing to the different catalytic capacities of four types of base-Cu-MOF nanozymes in the response to five common effective bioactive substances, we constructed the nanozyme-encoded array sensor for the identification of different bioactive compounds. As a result, the four-channel colorimetric sensor array was constructed, in which four laccase-like nanozymes were utilized as the sensing units, achieving high-throughput, high-sensitivity and rapid detection/identification of five common bioactive compounds in the concentration range of 1.5–150 μg mL −1 through different color output patterns. It is worth noting that the as-prepared sensor array can successfully distinguish the natural bioactive compounds in a variety of real samples. Furthermore, with the assistance of smartphones, we also designed a portable smart sensing approach for detecting the bioactive compounds effectively in food. This study has therefore not only provided an effective way for preparation highly effectively nanozymes, but also established a new sensing platform for intelligent sensing of bioactive components in food.
Kang Zhichao,Wang Tianye,Han Xuerong,Wang Chenxu,Zhang Shaoqing,Yu Hongwen
Corn planting is often associated with serious atrazine pollution and excessive corn straw amounts, causing severe threats to environmental and ecological security, as well as to green agricultural development. In this context, a Paenarthrobacter sp. KN0901 strain was applied to simultaneously remove atrazine and straw at low temperatures. The results of whole genome sequencing indicated that KN0901 encoded over nine straw biodegradation-related enzymes. In addition, 100% and 27.3% of atrazine and straw were simultaneously degraded by KN0901 following an incubation period of seven days at 15ºC and 180 rpm in darkness. The KN0901 strain maintained high atrazine and straw biodegradation rates under temperature and pH ranges of 4-25ºC and 5-9, respectively. The simultaneous atrazine and corn straw additions improved the microbial growth and biodegradation rates by increasing the functional gene expression level, cell viability, inner membrane permeability, and extracellular polymeric substance contents of KN0901. The hydroponic experiment results demonstrated the capability of the KN0901 strain to mitigate the toxicity of atrazine to soybeans in four days under the presence of corn straw. The present study provides a new perspective on the development of bioremediation approaches and their application to restore atrazine-polluted cornfields with large straw quantities, particularly in cold areas.
The use of disinfectants made from quaternary ammonium compounds (QACs) has greatly increased since the outbreak of SARS-CoV-2. However, the effect of QACs on wastewater treatment performance is still unclear. In this study, a commonly used QAC, i.e., benzyl dodecyl dimethyl ammonium bromide (BDAB), was added to a moving-bed biofilm reactor (MBBR) to investigate BDAB's effect on nutrient removal. When the BDAB concentration was increased to 50 mg L −1 , the ammonia removal efficiency (ARE) greatly decreased, as did the nitrate production rate constants (NPR). This inhibition was partly recovered by decreasing the BDAB concentration to 30 mg L −1 . Metagenomic sequencing revealed the functional genera present during different stages of the control (Rc) and BDAB-added reactors (Re). The enriched genera ( Rudaea , Nitrosospira , Sphingomonas , and Rhodanobacter ) in Rc mainly related to the nitrogen metabolism , while the enriched genera in Re was BDAB-concentration dependent. Functional genes analysis suggested that a lack of ammonia oxidase-encoding genes ( amo ABC) may have caused a decrease in ARE in Re, while the efflux pump-encoding genes emr E, mdf A, and opr M and a gene encoding BAC oxygenase ( oxy BAC) were responsible for BDAB resistance. The increase in the total abundance of antibiotic resistance genes (ARGs) in Re revealed a potential risk arising from BDAB. Overall, this study revealed the potential effect and ecological risks of BDAB introduction in WWTPs .
危险品化学品经营许可证（带存储）