摘要
表面增强拉曼散射(SERS)技术在痕量检测等领域中具有重要的作用,制备周期性微纳结构,构建表面等离子体耦合体系,是当前实现高性能SERS基底的主要方法之一。鉴于传统周期性微纳制备技术成本高、效率低等不足,提出了激光干涉诱导向前转移(LIIFT)技术,利用三光束LIIFT制备周期性Ag微点结构,并分析了结构基底的SERS特性。研究结果表明:基于LIIFT技术可以实现Ag微点结构的大面积、高效制备,并且通过调节三光束干涉光场周期,可以实现对Ag纳米颗粒的可控制备。最后,以典型食品添加剂罗丹明B(RhB)为检测对象,验证了Ag微点结构的SERS特性。该研究表明LIIFT技术是一种高效制备SERS芯片的有效途径,在食品、环境及生物工程等领域中具有潜在的应用价值。
Objective Surface-enhanced Raman scattering(SERS)plays an important role in trace detection and other fields of research.The use of periodic micro-nano structures has been a popular method for realizing high-performance SERS substrates.Traditional preparation technologies can prepare micro-nano structures with high precision and excellent quality.However,most of them have the limitations of strict environmental requirements,low efficiency,and high material dependence;therefore,it is necessary to develop alternative micro-nano periodic structure preparation techniques.Laser-induced forward transfer(LIFT)has been used to transfer almost all types of materials;however,it is limited in preparing periodic micro-nano structures.Laser interference lithography(LIL)has the advantage of high efficiency in preparing periodic micro–nano structures with large areas.Therefore,combining LIFT with LIL technology,a novel technique of laser interference-induced forward transfer(LIIFT)is proposed to transfer the periodic Ag microdots under three-beam laser interference in this study,which can overcome the shortcomings of traditional technologies and realize large-area metal micro-nano array structure manufacturing in a rapid,low-cost manner.Finally,the SERS properties of the Ag microdots transferred via LIIFT are tested and analyzed.Methods The donor film to be transferred consists of a quartz substrate,a polyimide(PI)sacrificial layer film mixed with carbon nanoparticles(CNPs@PI),and an Ag film.The preparation process of the CNPs@PI thin film is described in Ref.[16],and the Ag film is evaporated onto the CNPs@PI film(Fig.1).The principle of transferring a micro-dot via LIIFT is shown in Fig.2.The azimuth angles(0°,120°,and 240°)and transverse-magnetic(TM)mode of the polarization direction are chosen.Moreover,the effect of the interference period on the transferred microstructure is discussed.Finally,the Raman spectra of RhB on the transferred Ag micro-dots with different periods(9,11,and 15μm)are tested to analyze the SERS property of the transferred Ag micro-dots.Results and Discussions The transferred Ag micro-dot structure is observed on the receiving substrate,as shown in Fig.3(a1)-(a3).While the interference periods of the three beams are 9μm,the outline of the micro-dot structure can be observed,but there are many overlapping areas between adjacent micro-dots,as shown in Fig.3(a1).While the interference period increases to 11μm,a micro-dot with clear edge can be observed,as shown in Fig.3(a2).Upon increasing the period to 15μm,the clarity of the micro-dot is further improved[Fig.3(a3)].These results,combined with Fig.3(b1)-(b3),indicate that an increasing number of nanoparticles are distributed in the middle regions of a single micro-dot,leading to an improved resolution of each micro-dot with an increase in the period.The average diameter of the nanoparticles in the consistent area in the middle regions of the micro-dots with different periods is 129-141 nm,as shown in Fig.3(c1)-(c3).These results,combined with the statistical results of the numbers of Ag nanoparticles in the consistent area(Fig.4),indicate that,with an increase in the interference period,the average size of the Ag nanoparticles changes slightly,whereas the number of nanoparticles increases significantly.This is because the maximum intensity and contrast of the threebeam interference light field increase with the laser interference period(Fig.5),which affects the transferable mass of the Ag film and the distribution of Ag nanoparticles on the receiving substrate.The SERS characteristics of Ag micro-dot substrates with periods of 9,11,and 15μm are tested by selecting Rhodamine B(RhB)as the analyte with a concentration of 10-3 mol·L-1 and compared with the RhB Raman spectrum on the bare Si substrate.The results show that,while using an Si substrate covered with the transferred Ag nanoparticle micro-dots,the Raman intensity of RhB is significantly enhanced compared with that of the bare Si substrate.Simultaneously,the Raman intensity of RhB on the Ag nanoparticle micro-dot substrate increases with the micro-dot period(Fig.7).This can be attributed to the local surface plasmon resonance effect.With the increase in interference period,the density of the transferred Ag nanoparticles increases evidently,which can create more and stronger“hot spots,”making it easier to excite strong Raman signals.Conclusions Periodic Ag nanoparticle micro-dots are realized efficiently with three-beam laser interference LIIFT.The distribution of Ag nanoparticles in each micro-dot is controlled by adjusting the laser interference period.With the increase in the period of the laser interference from 9μm to 15μm,the density of Ag nanoparticles in the micro-dot increases.Finally,the Ag nanoparticle micro-dot substrates prepared by the three-beam LIIFT technology show significant SERS characteristics.Moreover,the Raman intensity of RhB on the transferred Ag micro-dots increases with the period of the micro-dots.This study demonstrates the potential application of LIIFT technology in the field of SERS chips.
作者
申惠娟
翁占坤
李昌立
邓锂强
韩太坤
Shen Huijuan;Weng Zhankun;Li Changli;Deng Liqiang;Han Taikun(School of Science,Guangdong University of Petrochemical Technology,Maoming 525000,Guangdong,China;School of Mechatronic Engineering and Automation,Foshan University,Foshan 528225,Guangdong,China;School of Science,Changchun University of Science and Technology,Changchun 130022,Jilin,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第16期296-304,共9页
Chinese Journal of Lasers
基金
国家自然科学基金面上项目(62175019)
广东省科技计划项目(X220961UZ230)
茂名市科技计划项目(2023012)
广东石油化工学院校级科研项目(博士启动类)(2023bsqd2009)。
关键词
激光技术
激光干涉光刻
激光诱导向前转移
Ag微点结构
表面增强拉曼散射特性
laser technique
laser interference lithography
laser induced forward transfer
Ag micro-spot structure
surface-enhancedRaman scatteringcharacteristics
