Preparation Of Nano-supercrystals And Its Application In Surface-enhanced Raman Scattering

Nanomaterials have application potential in many fields.However,the physical and chemical properties of nanomaterial monomers often cannot meet the needs of applications.Therefore,we turn our attention to how to controllable preparation of nanomaterial superlattice self-assembly structure,the performance of the constructed structure in the fields of optics,electricity,magnetism,etc.can be changed or improved.However,there are still some problems in the currently constructed assembly structure.The superlattice structure constructed by the template-free method has uneven heights,and the construction method steps are complicated.The patterned superlattice structure constructed by the template method has structural unevenness,complicated construction steps,high cost,poor versatility and other issues.The above problems limit the practical application of the self-assembly structure.Based on the above analysis,we propose a simple and feasible template-free tilt method to construct a uniform superlattice structure,and use this structure for surface enhanced Raman scattering(SERS)related research;and the use of photolithography template method to construct a patterned superlattice structure for wearable sweat SERS detection.Specifically,the main research content of this paper includes the following two aspects:(?)In this study,the template-free tilting method was used to assembly oleylamine-coated gold nanoparticles.Compared with the traditional planar drip coating method,the assembly method we constructed can control the direction of the meniscus and stabilize the movement direction of the contact line,avoiding uneven accumulation due to the coffee ring effect.After optimizing the conditions,a uniform structure could be constructed.Using Rhodamine 6G as the probe molecule,the SERS performance of the constructed structure was studied.The enhancement factor at 611 cm-1 was 2.57×105,and the relative standard deviation(RSD)of randomly selected 10 points was 5.05%,indicating that the constructed structure has good reproducibility.The built-up substrate has potential in practical applications.(?)In this study,the patterned assembly structure was constructed by the photolithography template method.The asymmetric modification of the silicon pillar substrate enables precise manipulation of the liquid,so that the nanoparticles could be stably and orderly pinned to the surface of the substrate.We use this method to construct a uniform patterned structure,the gold nanoparticles inside the structure are stacked in an orderly manner to form a superlattice structure.Different patterns could be constructed as needed,and this method is suitable for the assembly of various types of nanoparticles.Next,we used the constructed patterned structure for SERS detection of sweat,using pH and glucose as the tested substances to achieve in vitro detection,and designed a microfluidic device for in-situ collection and detection of sweat.The effect of in vitro testing is good,and it is finally used for in-situ testing attached to the body,showing its application potential in sports monitoring.