Scaled-up production of plasmonic nanoparticles using microfluidics: from metal precursors to functionalized and sterilized nanoparticles.

An exquisite control of synthesis parameters is generally required in nanomaterial synthesis to guarantee consistency in the essential characteristics such as size and shape. On the other hand, reliable scaled-up production of nanomaterials is required in order to achieve the production rates required for emerging nanotechnology applications while delivering a consistent product with the intended characteristics, avoiding the traditional batch-to-batch deviations. The continuous production of nanomaterials is challenging because of the difficulties involved in translating the complexity of nanomaterial synthesis into on-line operations. In this regard, microfluidic platforms stand out over conventional batch reactors due to their superior performance, easy scalability and reliability. Here, a continuous, scaled-up synthesis of high quality plasmonic hollow gold nanoparticles is reported for the first time. Not only was the throughput significantly higher than in a batch reactor, but also the microfluidic system allowed the on-line implementation of two new stages in nanomaterial production: surface functionalization and sterilization.