基于乙酸气体传感器的海洛因快速测定方法

研究并制作了石英晶体(谐振式)乙酸气体传感器。这种传感器利用晶体表面活性酶吸附乙酸气体引起石英晶体振荡频率的变化实现对海洛因分子的快速检测。实验结果表明:乙酸激酶(aceticacidki nase简称AK)膜石英晶体传感器对乙酸气体的灵敏度为10-4;而乙酰辅酶A(acetyl-COA)合成酶膜及聚赖氨酸膜石英晶体传感器对乙酸气体的灵敏度为10-5。     

Sustainable polylysine conversion to nitrogen-containing porous carbon flakes: Potential application in supercapacitors

The derived lysine from biomass fermentation is a naturally abundant renewable resource. However, the small molecular size of lysine limits its processing and application. On the other side, carbonization of polylysine into high-valued carbon materials is one of convenient options to apply for energy storage devices. Herein, we prepare polylysine@silica hybrid nanostructure through thermal polymerization of lysine and biosilicification of tetraethoxysilane (TEOS). Subsequently, nitrogen-containing porous carbon flakes (NPCF) are synthesized upon carbonization. Interestingly, the synthesized NPCF presents hierarchical porous framework structure with interconnected micro-meso-macro pores. Consequently, the NPCF delivers an excellent supercapacitor performance. For instance, our characterizations display specific capacitance up to 242 F/g at 1 mV/s and 186 F/g at 1 A/g, and could keep 96.3% initial capacity after 10,000 cycles at 10 A/g. These achievements are because of hierarchical porosity, proper nitrogen content, and accessible surface area of nanostructured NPCF. Therefore, our work creates a novel and sustainable route for fabricating NPCF with promising applications in the supercapacitors. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48214.     

壳聚糖/聚赖氨酸对柑橘的保鲜性研究

目的明确壳聚糖/聚赖氨酸复合膜对柑橘保鲜的影响。方法采用流延法制备聚赖氨酸质量分数(聚赖氨酸相对于壳聚糖)为0,1%,3%,5%,7%的壳聚糖/聚赖氨酸复合膜,对复合膜进行微观分析和红外光谱分析,采用光密度值法测试该膜的抑菌性,并用该复合溶液对柑橘浸泡后贮藏,测定贮藏期间柑橘各项保鲜指标的变化。结果复合膜表明光滑,内部结构均匀,其抑菌性随着聚赖氨酸质量分数的提高而增强。复合溶液涂膜减缓了贮藏期间柑橘感官分值的下降,减少了果实含糖量和维生素C含量的流失,降低了柑橘的质量损失率和腐败率。结论聚赖氨酸提高了壳聚糖膜的抑菌性,复合溶液涂膜对柑橘有良好的保鲜效果。