Abstract
To prepare the gold nanoparticles (AuNPs) with uniform sizes, fine morphology, and good monodispersity, a pulsed mixing microfluidic system based on PZT actuation was presented. The system includes PZT micropump and Y type micromixer. By adjusting voltage (entrance flow rate), pulsed frequency, phase, and other parameters, a variety of mixing modes can be achieved, so as to realize the controllable synthesis of nanoparticles in a certain range. By numerical simulation and analysis, the channel section size, entrance angle, and pulse frequency were optimized. Based on the optimized structure and working parameters, the test prototype has been manufactured in lab, and the related synthesis tests of AuNPs were carried out. The test results indicate that AuNPs with uniform morphology and good monodispersity can be synthesized using the system with the section size (0.4 mm × 0.4 mm), the entrance channel angle (60°) under condition of the pulsed frequency (300 Hz), and the entrance flow rate (4 mL/min). The average diameter and its standard deviation of AuNPs synthesized were 21.6 nm, 4.83 nm, respectively. The research work above can be applied to the fields such as the controlled synthesis of noble metal nanoparticles, biomedicine, and microchemical system.
Highlights
It has been applied to a chemical analysis with Localized Surface Plasmon (LSP) [19] and Surface Enhanced Raman Spectroscopy (SERS) [20, 21]; both the average size of the gold nanoparticles and the size distribution are critically important factors in such applications [22]
While the absorbance maximum reflects the concentration of particles size, which indicates that the concentration of AuNPs of sample number 2 is the largest, the concentration of AuNPs of sample number 3 is the minimum
Note that samples of synthesized AuNPs showed the typical and unique optical characteristics of gold colloid, and surface plasmon resonance (SPR) by AuNPs was observed at 500∼550 nm [37, 38], which further confirms the synthesis of AuNPs
Summary
Gold nanoparticles (AuNPs) have received tremendous growing attention during the recent few years because of their unique characteristics [1,2,3,4] and have already found many kinds of applications in catalysis [5,6,7], sensing [8,9,10], diagnosis [11,12,13], biomedicine [1, 14, 15], drug delivery [16,17,18], and so forth. The most of AuNPs synthesis process was achieved by reducing the gold salt in the water phase [27]. On the basis of the method, microfluidic mixer has been used for the synthesis of gold nanoparticles by scholars. The continuous flow methods using micromixers have been proven to be successful alternative methods with a possibility to synthesize large quantities with better control on the distribution, shape, and size of the particles [28, 29]. A pulsed mixing microfluidic system for the synthesis of AuNPs is developed. The mechanism of gold nanoparticles formation and pulsed micromixing is introduced. The gold nanoparticles are prepared and the test results are discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
