Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371.
Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR) , 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634.
ACS Appl Mater Interfaces. 2017 Nov 15;9(45):39635-39640. doi: 10.1021/acsami.7b13917. Epub 2017 Oct 31.
Miniaturizing the continuous multistep operations of a factory into a microchemical plant offers a safe and cost-effective approach to promote high-throughput screening in drug development and enforcement of industrial/environmental safety. While particle-assembled microdroplets in the form of liquid marble are ideal as microchemical plant, these platforms are mainly restricted to single-step reactions and limited to ex situ reaction monitoring. Herein, we utilize plasmonic liquid marble (PLM), formed by encapsulating liquid droplet with Ag nanocubes, to address these issues and demonstrate it as an ideal microchemical plant to conduct reaction-and-detection sequences on-demand in a nondisruptive manner. Utilizing a two-step azo-dye formation as our model reaction, our microchemical plant allows rapid and efficient diazotization of nitroaniline to form diazonium nitrobenzene, followed by the azo coupling of this intermediate with target aromatic compound to yield azo-dye. These molecular events are tracked in situ via SERS measurement through the plasmonic shell and further verified with in silico investigation. Furthermore, we apply our microchemical plant for ultrasensitive SERS detection and quantification of bisphenol A (BPA) with detection limit down to 10 amol, which is 50 000-fold lower than the BPA safety limit. Together with the protections offered by plasmonic shell against external environments, these collective advantages empower PLM as a multifunctional microchemical plant to facilitate small-volume testing and optimization of processes relevant in industrial and research contexts.
将工厂的连续多步操作微型化到微化学工厂中，为促进药物开发中的高通量筛选和执行工业/环境安全提供了一种安全且具有成本效益的方法。虽然以液滴为核的粒子组装微液滴（即液体大理石）是理想的微化学工厂，但这些平台主要限于单步反应，并且仅限于原位反应监测。在这里，我们利用等离子体液滴（PLM）来解决这些问题，该液滴由 Ag 纳米立方体包裹液滴形成，它作为一种理想的微化学工厂，可以以非侵入式的方式按需进行反应和检测序列。我们使用两步偶氮染料形成作为模型反应，我们的微化学工厂允许硝基苯胺快速有效地进行重氮化以形成重氮硝基苯，然后将该中间体与目标芳族化合物进行偶联以生成偶氮染料。这些分子事件通过等离子体壳进行原位 SERS 测量进行跟踪，并通过计算进行进一步验证。此外，我们将微化学工厂应用于超灵敏的 SERS 检测和定量分析双酚 A（BPA），检测限低至 10 amol，比 BPA 安全限低 50,000 倍。结合等离子体壳对外界环境的保护，这些优势使 PLM 成为多功能微化学工厂，能够促进工业和研究背景下相关过程的小体积测试和优化。
