Fabrication Of Gold Nano-particles And Dark Field Observation System

Gold nanoparticles have become a hotspot in the area of nanomaterials research because of its unique optical properties,non-toxic and bio-compatibility,which are widely applied to biological imaging and micro-nano sensors.It is very important to use effective methods to fabricate stable gold nanoparticles with uniform particle size.The paper is concentrated on the fabrication of gold nanoparticles and imaging of gold nanoparticles,the main works include:1.A small paddle stirrer is designed and manufactured by using a AT89C51 chip as a control device.The stirrer uses the pulse width modulation technology to control speed,and computer control software is programmed to control and display the motor speed in real time and the remaining value of the working time.By the serial communication port,the control information can be exchanged between the chip and the computer.The stirrer can achieve continuous,unlimited control of the DC motor speed and working hours,respectively.2.The stirrer is used for the fabrication of gold nanoparticles.Gold nanoparticles with different particle sizes are successfully obtained by trisodium citrate reduction and seed growth methods,which are characterized by transmission electron microscopy.According to the different reaction mechanism and the results of transmission electron microscopy,the optimum method is obtained to fabricate stable spherical gold nanoparticles with large particle size.Comparing with the experimental results of artificial agitation and agitation of the stirrer,stirring with uniform speed is very important for the fabrication of stable gold nanoparticles with uniform particle size.3.Based on the ordinary optical microscope,a new type of dark field microscopy imaging system was designed and constructed by processing the emergent light of the objective lens.The system does not need to limit the numerical aperture of the objective lens to improve the imaging resolution and application range,and is especially suitable for imaging systems requiring large numerical aperture objectives.Finally,the imaging system is used to observe and image the gold nanoparticles in real time,and the nanometer scale image of gold nanoparticles is obtained.