Preparation and characterization of rare earth fluorescent anti-counterfeiting fiber via sol-gel method

A benzoic acid rare earth(Tb) complex was synthesized and characterized.The excitation and emission spectra of the complex were investigated,and then pure organic complex was incorporated with inorganic matrices(SiO2) through sol-gel method.The composition and structure of the hybrid complex was characterized through the IR spectra,TG,TEM and fluorescent spectrometer.Furthermore,the polypropylene(PP) fluorescent fiber with the organic-inorganic hybrid was prepared by melt spinning.The fluorescent and mechanical properties of the fiber were also tested.The results showed that after sol-gel coating the average particulate dimension of the hybrid rare earth complex was less than 100 nm and thermal stability was improved.Meanwhile,the fiber possessed excellent fluorescent and mechanical properties,which could be used as a candidate applied to excellent fluorescent anti-counterfeiting fiber.

Multicolor Anti-counterfeiting Strategy and Synchronous High Capacity Storage Based on Acidochromic Organic Fluorescent Materials

Comprehensive Summary Many industries are plagued by economic losses and product failures caused by counterfeit goods.Therefore,advanced anti-counterfeiting techniques are continuously needed.In this study,we constructed a series of acid-base sensitive cyclic chalcone dyes A—F by modifying different electron-donating groups.Differences in acid sensitivity of different structures are well rationalised by NMR and theoretical calculations.Aniline is difficult to protonate than fatty amines,so there is a difference in fluorescence.Hiding and anti-counterfeiting of information is achieved by this phenomenon.Powder X and Y are the anti-counterfeit fluorescent powder containing montmorillonite and cyclic chalcone,which have orange fluorescence and the very similar appearance.However,under the influence of acid the Powder X containing triphenylamine modified cyclic chalcone shows red shifted fluorescence and Powder Y containing morpholino and diethylamino groups modified cyclic chalcone shows blue shifted fluorescence.Therefore,the anti-counterfeiting strategy based on cyclic chalcone is not only limited to UV-irradiated fluorescence development,but also has more colorization and pattern variations with the aid of acid developer.Data encryption and decryption of numbers,English alphabets and Chinese characters have been realized using A—F,which have great potential for practical applications.

Radiation-induced attenuation self-compensating effect in super-fluorescent fiber source

The compact super-fluorescent fiber source （SFS） output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation （RIA） self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation （RIBA） at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward （DPB） configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad （Si） gamma-ray irradiation.

Underwater Optical Fiber Fluorescent System for Measuring Chlorophyll-a Concentration

Using optical fiber fluorescent technology,a new method for measuring alga concentration in water is presented. The system can realize on line measurement for alga concentration using He Ne laser as the light source. It can also effectively detect weak signals. The system with a passive sensor head has such advantages as simple structure, high sensitivity and high accuracy. It has been demonstrated that this system can be used to monitor water quality and can also be used to survey some matter.

All Fiber-optic Fluorescent Spectral Measurement and Analysis on Alga Chla/c Characteristics

The fluorescent principle used for measuring alga characteristic parameters and the optimum structure design of the instrument are discussed. The fluorescent spectrum of Chla/c and the time-resolved different spectrum ΔA(λ,t) are given. The research provides an effective method for considering the density and the classification of algae, which will be helpful to monitor sea pollution.

Excitation-wavelength-dependent fluorescent organohydrogel for dynamic information anti-counterfeiting

Anti-counterfeiting labels with various fluorescent colors are of great importance in information encryption-decryption,but are still limited to static information display.Therefore,it is urgent to develop new materials and encryption-decryption logic for improving the security level of secret information.In this study,an organohydrogel made up of poly(N,N-dimethylacrylamide)(pDMA)hydrogel network and polyoctadecyl methacrylate(pSMA)organogel network that copolymerized with two fluorophores,6-acrylamidopicolinic acid moieties(6APA,fluorescent ligand)and spiropyran units(SPMA,photochromic monomer),was prepared by a two-step interpenetrating method.As UV light of 365nm and 254nm can both cleave C_(spiro)-O bonds of SPMA,and the green fluorescence of 6APA-Tb^(3+) can only be excited by 254nm light,the organohydrogel displays yellow and red under the irradiation of 254nm and 365 nm,respectively.In addition to wavelength selectivity,these two fluorophores are thermal-responsive,leading to the fluorescence variation of the organohydrogel during heating process.As a result,secret information loaded on the organohydrogel can be decrypted by the irradiation of UV light,and the authenticity of the information can be further identified by thermal stimulation.Our fluorescent organohydrogel can act as an effective anti-counterfeiting label to improve the information security and protect the information from being cracked.

Sustainable curcumin-based smart tough fluorescent hydrogels for anti-counterfeiting applications

There is currently great interest in developing an environment-friendly,low-cost,and scalable approach for producing stimuli-responsive fluorescent hydrogels(FHs)with excellent mechanical property,rewritable fluorescence,and dual anti-counterfeiting capabilities.Herein,by applying natural,environment-friendly,and sustainable curcumin as a responsive agent,tough pH-responsive FHs(pH-FHs)are fabricated via a facile preparation strategy.These materials have outstanding mechanical performances:ultimate stress of 180 kPa,an ultimate strain of~2500%,and good anti-fatigue performances against compression.These pH-FHs are able to sense ammonia and formaldehyde gas,resulting in both a color change and fluorescence for dual anti-counterfeiting functionality.This sensing information is stored individually by the pH-FHs and could be externally removed using formaldehyde gas to achieve a rewritable system.Our study provides valuable insights that are expected to facilitate the development of smart FHs for information encryption and anti-counterfeiting applications.

Optical Fiber Lightening for Fluorescence Signal Detection with Thermal Stability in Dentistry

Dental caries diagnosis system has been made with a fiber lighting, camera module and band pass filter. By simply aligning a 405 nm LED (Light Emitting diode) chips directly connected polymer fibers, a compact lighting for dental fluorescence imaging could be implemented. Special designed fiber holder with proper hole diameter was fabricated to directly connect polymer fibers with 1 mm fiber diameter and increased coupling efficiency between fibers and LEDs. Fibers connected to fiber holder were polished by polishing machine to reduce insertion loss of the fiber. Experimentally, an optical insertion loss of the fiber bundle of up to 0.8 dB was achieved. Further, LED array module was packaged with equally spaced LED chips with fiber holder on metal. Fiber lightening was fabricated with directly coupled between LED array module and fiber bundle by UV epoxy without focusing lens in order to lower the lightening temperature of intraoral camera in the human mouth. The measured temperature of fabricated fiber lightening was about 25 degree celcius. To achieve a fluorescence image and dental caries diagnosis, the proper optical filter, camera module, 405 nm fiber bundle lighting and software were investigated. The performance of the fluorescence intraoral camera with fiber lightening is confirmed by fluorescence image of human tooth.

A Fluorescence Optical Fiber Sensor for Amrinon Using a New Oxazole Compound

A new oxazole compound, 1,4 bis(naphtho[1,2 d][1,3]oxazol 2 yl)benzene(BNOB) was synthesized and incorporated into a thin plasticized polymeric membrane for sensing Amrinon. The sensor exhibits a linear response to Amrinon in the range of 7 98×10 -7 —1 52×10 -4 mol/L at pH 3 28—4 04. The response mainly originates from the Primary Inner Filter Effect, which causes a decrease in the fluorescence intensity of the sensor membrane. The distinct advantages of the proposed sensor are of full reversibility, high sensitivity and selectivity as well as short response time(<1 min), indicating that the sensor can be used to monitor Amrinon in serum samples.

Optical Fiber Thermometer Based on the Fluorescence Life time

Anew opticalfiberfluorometricthermometerbased onthetemperature dependence ofthefluorescencelifetime of phosphoris described. The phase-locked detection (PLD) system is used to measure fluorescencelifetime. The characteristics ofthermometerare discussed and the experimentresults are given.

An Optical Fiber Sensor for Simultaneous Measurement of pO2 and pH

Whether in the monitoring of critically ill patients such as shock, respiratory failure, brain injury, or in major anesthesia surgeries, it is necessary to evaluate the patient’s pO2 and pH. An optical fiber sensor presented is capable of monitoring the presence of oxygen partial pressure (pO2) and pH in the real-time. The sensor is based on fluorescence sensing of polymer immobilized in the oxygen/pH-sensitive membranes and covalently attached to the optical fiber probe. The design of this sensor uses LED as light source, which is an excitation light source, inducing specific wavelengths of fluorescence on the oxygen/pH-sensitive membrane. The intensity and lifetime of fluorescence are related to the pO2 and pH. So the pO2 and pH can be measured by the relationship between the pO2/pH values and the intensity and lifetime of fluorescence. The signal conditioning system based on DSP and STM32 was used to store and process data, and display test values. The response of the sensor for pO2 and pH monitoring with nitrogen (N2) as a balancing gas in the laboratory was performed. Finally, the oxygen/pH sensing scheme presented in this work is intended for using in biological, medical and environmental applications.

Fiber-fluorescence in situ hybridization analyses as a diagnostic application for orientation of microduplications

Microduplications are normally invisible under microscopy and were not recognized before chromosomal microarray testing was available. Although it is difficult to confirm the orientation of duplicated segments by standard fluorescence in situ hybridization(FISH), our data indicates that fiber-FISH analysis has the potential to reveal the orientation of duplicated and triplicated segments of chromosomes. Recurrent microduplications reciprocal to microdeletions show tandem orientations of the duplicated segments, which is consistent with a non-allelic homologous recombination mechanism. Several random duplications showed tandem configurations and inverted duplications are rare. Further analysis is required to fully elucidate the basic mechanisms underlying such duplications/triplications.

Manipulable multipurpose nanothermometers based on a fluorescent hybrid glass fiber microsphere cavity

Fluorescent nanothermometers for remote temperature measurement at the micro/nanoscale have stimulated growing efforts in developing efficient temperature-responsive materials and detection procedures.However,the efficient collection and transmission of optical signals have been a tremendous challenge for practical applications of these nanothermometers.Herein,we design an all-fiberized thermometry based on a fiber-coupled microsphere cavity coated with thermo-sensitive NaYF_(4)∶20%Yb^(3+);2%Er^(3+)@NaYF_(4)nanocrystals(NCs),allowing for spatial temperature sensing with resolution down to the few-micrometer scale.In our design,the microsphere efficiently excites the NCs and collects their upconversion emissions,and the use of a fiber splitter coupled with the microsphere allows for lossless routing of excitation and emitted light.We demonstrate the use of this all-fiber temperature sensor in diverse environments,especially in strongly acidic and alkaline conditions.Leveraging the high flexibility of commercial silica fiber,this all-fiber temperature ensor was employed for stable fixed-point real-time temperature measurement and multipurpose temperature recording/mapping in opaque environments,microscale areas,various solutions,and complicated bent structures.Thus,the demonstrated design could have strong implications for the practical use of nanothermometers in various possible scenarios,especially monitoring temperatures in diverse physiological settings.

多芯光纤荧光定量检测耦合系统设计

为提高多芯光纤荧光检测灵敏度,本文基于多芯光纤的空间传导理论模型,分析了多芯光纤的数量、激发光纤纤芯半径、接收光纤纤芯半径以及它们的数值孔径等对多芯光纤耦合效率的影响。针对提高耦合效率,设计和优化了耦合系统中非球面透镜的曲率半径和各面间距,基于分析设计优化的参数构建多芯光纤荧光定量检测系统,并对不同浓度梯度的罗丹明6G溶液进行定量测试,与多芯直接耦合对比,文章设计的多芯光纤耦合系统其激发光和发射光耦合效率由低于10%,提升了80.171%和95.314%,最低检测浓度低至2.08759551×10^(-9)nM/L,此浓度下荧光光强值较直接耦合提升了4.5倍。进一步验证了多芯光纤耦合系统射的可行性。说明通过增加光学耦合系统能有效提高光纤式荧光定量检测灵敏度及能够满足应用需求。

用于荧光显微技术的多波长激光耦合系统

为了满足荧光显微镜技术对多波长单模耦合输出激光的需求,研究了400~680 nm内多波长激光耦合进单模光纤的技术,设计了三片式耦合透镜组很好地消除了不同波长耦合时的色差以提高耦合效率,同时考虑光纤耦合调试难度大的问题,设计了能快速简单完成耦合调节的耦合光纤部件结构以及耦合调试的方法,通过实验测试荧光成像常用的4种波段激光(405,488,561,638 nm),耦合效率均大于65%。实验结果达到了较高的光纤耦合水平,证明该多波长激光耦合器性能优异。同时,由于耦合器装调简单且成本低,本文的工作具有进一步商业化的价值,且为多波长单模耦合激光器国产化打下了坚实的基础。

基于荧光猝灭原理的比率式光纤溶解氧传感器研究

溶解氧浓度的准确测定在医疗应用、海洋监测、工农业生产等领域中,起到至关重要的作用。本篇论文提出了一种比率式光纤溶解氧传感器,以四乙氧基硅烷(TEOS)和正辛基三乙氧基硅烷(Octyl-triEOS)为前驱体的有机改性硅酸盐(ORMOSILs)作为载体基质,选用三(4,7-联苯-1,10-邻菲啰啉)二氯化钌(Ru(dpp)_(3)^(2+))为氧敏感染料,选用7-氨基-4-(三氟甲基)香豆素(AFC)为参比染料。吸收光谱表明,氧敏感染料和参比染料可以被中心波长为405nm的光源激发。发射光谱表明,氧敏感染料和参考染料的发射波长没有光谱重叠,因此可以使用比率法测量溶解氧浓度。通过溶胶-凝胶工艺制备的ORMOSILs将氧敏感染料和参比染料固定在塑料光纤端部,从而形成复合氧敏感薄膜,对传感膜的厚度和疏水性进行了表征,传感膜的厚度为569μm,水接触角为81°。将该传感器在水溶液中进行了测试,在光源激发下,氧敏感染料和参考染料在605和490nm处有明显的发射峰,随着溶解氧浓度的增加,氧敏感染料的荧光强度降低,而参比染料的荧光强度稳定在某一数值,通过测量氧敏感染料与参比染料的比率,达到检测氧浓度的目的。采用Stern-Volmer方程对溶解氧浓度和荧光强度比进行线性拟合,该传感器在0~20.05mg·L^(-1)溶解氧范围内,Stern-Volmer拟合度可达98.22%,灵敏度可达0.4334/[O_(2)],从饱和氮溶液到饱和氧溶液传感器的响应时间为12s,从饱和氧溶液到饱和氮溶液传感器的恢复时间为144s,引入非对称因子ASY表明传感时间的不对称性。对传感器的光稳定性和重复性进行了测试,比率式光纤传感器可以克服光源波动,相对单荧光强度传感有更强的稳定性。

基于荧光强度比的毛细管液芯光纤温度传感器

针对现有光纤荧光温度传感探头制备复杂的问题,本文提出了一种制备简单、成本低廉且性能优异的基于毛细管液芯的光纤荧光温度传感器。首先将对温度敏感的罗丹明B和对温度不敏感的罗丹明123的混合溶液作为温敏材料封装在不锈钢毛细管中制备成传感探头,利用两者荧光发射峰强度的比值进行温度传感。之后对传感探头中混合溶液的浓度和毛细管的结构参数进行了优化,并对传感器的性能进行了测试,最终将其应用于实际生活温度检测中。实验结果表明:该传感器的温度响应范围为30~70℃,荧光强度比与温度之间呈二次相关,拟合相关系数高达0.9984,且具有很好的准确性、重复性和稳定性,使用时间可达3个月以上,能很好地应用于对日常生活中温度的检测。该光纤荧光温度传感器在实时监测和远端探测方面具有很大的潜力。

SF_(6)放电分解产物荧光抑制光纤增强拉曼光谱动态高灵敏检测研究

分析SF_(6)放电分解产物组分和含量的动态变化是SF_(6)封闭式组合电器(Gas-Insulated Switchgear,GIS)状态诊断的关键。本文提出荧光抑制光纤增强拉曼光谱(Fiber-Enhanced Raman Spectroscopy,FERS)动态高灵敏检测方法。首先搭建了SF_(6)放电分解产物荧光抑制FERS检测系统,通过结合CCD数字滤波和小孔空间滤波的协同荧光滤波方法,系统信噪比提升228.4%;基于Allan方差分析确定了系统最佳积分时间为220 s。然后在2 bar压强、220 s积分时间下,基于标准混合气体样品分析确定了用于同时定性与定量分析SF_(6)放电分解产物SOF_(2),SO_(2)F_(2),COS,CF_(4),SO_(2),CO_(2),CO的特征拉曼谱峰,并计算得检测下限分别为1.95 ppm,1.78 ppm,0.83 ppm,2.41 ppm,0.93 ppm,2.51 ppm,6.69 ppm。最后通过连续168 h的GIS等比缩小模型局部放电实验证明了上述系统可实现SF_(6)放电分解产物的动态高灵敏检测,且与气相色谱法结果偏差小于±5%。实验结果表明,本文提出的检测方法可为GIS的安全运行提供技术支撑。

一种新型二氧化硅多孔材料固定化酶光纤葡萄糖传感器的研究

目的 研制一种新型的基于氧敏感指示剂Ru(bpy)3Cl2和固定化葡萄糖氧化酶(GOD)的复合敏感膜光纤传感器,用于实时检测葡萄糖溶液质量浓度。方法 以多孔SiO_(2)纳米粒子为载体固定GOD,并采用溶胶-凝胶法同时加入Ru(bpy)_(3)Cl_(2)制备葡萄糖敏感膜,通过提拉法在光纤端面沉积敏感膜制成光纤传感探头,搭建光纤传感器用于实时检测葡萄糖溶液质量浓度。结果 光纤传感器检测葡萄糖溶液质量浓度为50~900mg/dL(2.78~50.00mmol/L),在用于实时监测葡萄糖溶液质量浓度变化时响应时间短,测试标准曲线线性良好。结论 SiO_(2)多孔材料固定化酶光纤葡萄糖传感器具有灵敏度高、响应速度快、检测范围大等优点,未来可以检测人体血液中的葡萄糖质量浓度。

Monitoring of Sweat pH and Dual-Mode Anti-Counterfeiting from Metal-Organic Framework-Based Multifunctional Gel

Monitoring of sweat pH plays important roles in physiological health,nutritional balance,psychological stress,and sports performance.However,the combination of functional MOFs with phosphorescent material to acquire the real-time physiological information,as well as the application of dual mode anti-counterfeiting,has seldom been reported.Herein,we developed multifunctional gel films based on MOFs and phosphorescent dyes which responded to H+ions and the related mechanism was studied in detail.Upon exposure to H+,the composite gel film exhibited decreased fluorescent signal but enhanced room temperature phosphorescence(RTP),which could be utilized for sweat pH sensing through a dual-mode.Moreover,multifunctional gel films exhibited a potential application in information encryption and anti-counterfeiting by designing of stimulus responsive multiple patterns.This research provided a new avenue for portable and non-invasive sweat pH monitoring methods while also offering insights into stimulus-responsive multifunctional materials.