Preparation Of Gel Microsphere Array And Its Application In Visual Detection

As a new born and rapidly developed technology,droplet-based microfluidic has a wide application in the field of physics,chemistry,biomedicine,optics,and other interdisciplinary researches.However,due to the complexity of the droplet generation processes,the high cost of the devices,and the cumbersome operation of droplet manipulation,the development of droplet-based microfluidic is greatly limited.Therefore,it has important practical value in the development of low-cost,cross-size,high-throughput automatic droplet generation device.In this study,an automatic droplet generation device was developed.The device is composed of a simple droplet-based microfluidic and a high-precision XY mobile platform.This device can be used to simply fabricate microdroplets and microspheres with an adjustable or designable pattern.Thus,the device is expected to lay a technical foundation for the promotion and application of droplet technology in chemistry,biology,optics,and materials science.Based on commercial components and XY mobile platforms,this study carried out the research on the construction of droplet microfluidic devices,the fabrication of microdroplets and microspheres pattern,and the application of visual detection in metal ions.The specific experimental results are as follows:1.Aportable droplet-based microfluidic device was fabricated and used for droplet generation.The device was constructed using commercial micropipe s.Single and double microdroplets can be controllablely produced by the device.In addition,microdroplets of ethoxylated trimethylolpropane triacrylate(ETPTA)in the size range from micrometers to millimeters were successfully prepared by adjusting the flow rates of the dispersephase and continuous phase,the size of the outlet pipe and the distance between the spotting needle and the outlet pipe.2.An automatic microdroplet generation device was assembled by a combination of the droplet-based microfluidic device and XY mobile platform for controllable preparation of microspheres.Thus,microdroplet arrays can be simply generated by using this device.The arrangement of droplets can not only effectively avoid the fusion of droplets due to mutua l contact but also usable to produce microspheres under ultraviolet light(UV)illumination in 7 s.Consequently,poly(ethoxylated trimethylolpropane triacrylate)(PETPTA)microspheres with different shape and size were prepared by this method.3.Patterned arrangement of microspheres.Many patterns of microsphere arrays were successfully prepared by designing and changing the trajectory of droplets,such as rectangle,spiral,snowflake,gear,C hinese knot,star,flower,number,and letter.In addition,ETPTA porous microspheres with single,double and triple opening pores were also arrayed by controlling the flow rates of inner,middle and outer phases.4.Application of microsphere arrays in visual detection.Firstly,the ETPTA microsphere arrays with a diameter of 580 ?m and the shape of letters Cu,Fe and Cr were fabricated.Secondly,a spherical cavity of poly(dimethylsiloxane)(PDMS)microwell arrays with corresponding patterns were successfully prepared by using the microsphere arrays as templates.Then,the micropwell arrays were filled with the mixture solution of acrylamide,water and polyethylene glycol diacrylate(PEGDA)with a mass ratio of 3 : 1 : 6.After curing with UV light,a hydrogel microsphere arrays were simply fabricated.Finally,the hydrogel microsphere arrays were used for the visual detection of heavy metal ions.The experiment results indicated that C u2+,Fe2+and Cr6+ ions were shown yellow,red and purple colors,respectively.The visual detection of these ions can be realized quickly,accurately and efficiently by the mobile phone.In conclusion,a low cost droplet-based microfluidic device was quickly fabricated with commercially available micropipes for the generation of microdroplets with sizes in the micrometer to millimeter diameter ranges.Microdroplet and microsphere patterns can be massively prepared by the combination of the device and XY mobile platform.The advantages of the method include their low cost,portability,and simple generation of microdroplets or microsphere patterns.Therefore,the proposed method is expected to further promote the development of droplet microfluidic technology.