Counterfeiting is one of the most serious problems in the consumer market. One promising approach for anti-counterfeiting is to attach a low-cost Radio-frequency Identification (RFID) tag to the product authentication...Counterfeiting is one of the most serious problems in the consumer market. One promising approach for anti-counterfeiting is to attach a low-cost Radio-frequency Identification (RFID) tag to the product authentication. In this paper, we propose an RFID system for detecting counterfeiting products. This RFID system consists of the tag authentication protocol and the database correction protocol. We use the tag authentication protocol for authenticating tags without revealing their sensitive information. This protocol also allows the customer to freely inquire the tag. To prevent the widespread of the counterfeit products, we use the tag status information along with tag identity information. Meanwhile, the database correction protocol guarantees the correctness of the tag status. Our anti-counterfeiting system is the first work considering the seller who plays an important role in the consumer product supply chain. Finally, we show that anti-counterfeiting system is quite secure against counterfeiting and the tag authentication protocol is lightweight enough to be implemented in RFID-based applications.展开更多
Novel hydrophilic NaYF4:Yb^3+,Tm^3+@NaGdF4:Ce^3+,Eu^3+double-jacket microtubes(DJMTs)with upconversion/downconversion dual-mode luminescence were designed and prepared through epitaxial growth of NaGdF4:Ce^3+,Eu^3+she...Novel hydrophilic NaYF4:Yb^3+,Tm^3+@NaGdF4:Ce^3+,Eu^3+double-jacket microtubes(DJMTs)with upconversion/downconversion dual-mode luminescence were designed and prepared through epitaxial growth of NaGdF4:Ce^3+,Eu^3+shell onto the NaYF4:Yb^3+,Tm^3+microtube via poly(acrylic acid)(PAA)mediated hydrothermal method.It is demonstrated that PAA ligand played an important role in guiding the direct growth of NaGdF4:Ce^3+,Eu^3+shell onto the surface of NaYF4:Yb^3+,Tm^3+parent microtubes.The growth of NaGdF4:Ce^3+,Eu^3+shell experienced a crystal phase transition fromβ-NaGdF4 andβ-NaYF4 mixture toβ-NaYF4@NaGdF4 composite crystal,and morphology evolution from mixture ofβ-NaGdF4:Ce^3+,Eu^3+nanorods andβ-NaYF4:Yb^3+,Tm^3+microtubes to NaYF4:Yb^3+,Tm^3+@NaGdF4:Ce^3+,Eu^3+DJMTs.The formation mechanism of DJMTs was the dissolution−renucleation ofβ-NaGdF4:Ce^3+,Eu^3+nanorods and the growth ofβ-NaGdF4:Ce^3+,Eu^3+shell via the classical Ostwald ripening mechanism.The as-prepared DJMTs could exhibit blue upconversion and red downconversion luminescence,which was further made into environmentally benign luminescent inks for creating highly secured and fluorescent-based anti-counterfeiting patterns via inkjet printing.展开更多
Pharmaceutical counterfeiting is a health scourge responsible for several cases of morbidity and mortality. Counterfeit medicines cause therapeutic failure, emergence of resistance in the treatment of infections. This...Pharmaceutical counterfeiting is a health scourge responsible for several cases of morbidity and mortality. Counterfeit medicines cause therapeutic failure, emergence of resistance in the treatment of infections. This study was conducted in order to identify counterfeit and authentic medicines in circulation in Lubumbashi. The study included artemether and artesunate for oral administration. A careful visual inspection of medicine, investigation of authenticity of pharmaceutical products from manufacturers and pharmaceutical regulatory authorities and determination of content were used as study parameters. 52 samples: 37 artemether and 15 of artésunate were collected. 7 samples (13%) have proven to be counterfeit. Artemether was the most counterfeit (71%) and 29% for artesunate. 6 (12%) samples were substandard according to the international pharmacopoeia in terms of content of active ingredient. Sixty-seven percent of non-compliance concerned counterfeit medicines. The proportion of non-compliance is highest among counterfeit medicines (71.43% vs 2.22%;p = 0.000004). It is obvious that strengthening the capacity of the drug regulatory authority of the DRC reduces the influx of counterfeit drug and substandard.展开更多
February-15,virtual ITU is organizing a series of webinars on Combating counterfeiting and stolen information and communications technology(ICT)devices.The Episode 1:"Existing challenges and solutions on combatin...February-15,virtual ITU is organizing a series of webinars on Combating counterfeiting and stolen information and communications technology(ICT)devices.The Episode 1:"Existing challenges and solutions on combating counterfeiting of ICT devices",will take place fully virtually on 15 February 2023.展开更多
Highly ordered films of polystyrene(PS)micro-spheres have demonstrated various merits in optoelectronic devices,given their size-and thickness-dependent optical properties.So far,various solution strategies have been ...Highly ordered films of polystyrene(PS)micro-spheres have demonstrated various merits in optoelectronic devices,given their size-and thickness-dependent optical properties.So far,various solution strategies have been developed for making such highly ordered films,which have suffered from the lack of precise control on the film thickness(i.e.,layer number of micro-spheres).Here,we developed a facile fibrous liquid bridge strategy for fabricating highly ordered PS micro-sphere films,featured as the finely tunable mono-to multi-layer.Guided by a horizontally placed fiber with both ends passing through a capillary tube,respectively,the solution was transferred steadily onto the target substrate forming a homogeneous liquid film,whose dewetting process thus confines the assembly ofmicro-spheres in a well-controllablemanner.Depending on both the solution-shearing speed and the local concentration,a dynamic equilibrium between liquid transfer and evaporation was realized,which enables the formation of highly ordered micro-sphere films with finely tunable layer numbers.We demonstrated the angle-specific information encryption for anti-counterfeiting by utilizing patterned PS micro-sphere films that modulate structural colors based on layer-dependent optical responses.The result offers a new perspective for fabricating highly ordered film with tunable layers.展开更多
Developing advanced fluorescence anti-counterfeiting technologies can enhance the effectiveness of current anti-counterfeiting strategies by addressing their limitations.To meet this demand,an afterglow material Y_(2)...Developing advanced fluorescence anti-counterfeiting technologies can enhance the effectiveness of current anti-counterfeiting strategies by addressing their limitations.To meet this demand,an afterglow material Y_(2)CaSnGa_(4)O_(12):Pr^(3+)(YCSG:Pr^(3+))exhibiting photochromic phenomena was engineered.This design capitalizes on the opposite effects of traps and color centers on emission intensity,thus ingeniously achieving excitation wavelength-dependent modifications in luminescence intensity.A thorough analysis of the energy conversion processes before and after irradiation by ultraviolet light was undertaken to discern the dominant role of color centers and traps under varying excitation conditions.Thereby,the dynamic energy conversion processes from traps and color centers to the luminescence center are established,showing a variety of output modes related to wavelength,irradiation time and distance.Furthermore,discrepancies in energy transfer efficiency from traps to different energy levels result in temperature-dependent spectral variations,consequently manifesting distinct colors in afterglow and luminescence at each temperature.This pioneering approach serves as a valuable blueprint for the development of multimode dynamic anti-counterfeiting materials capable of adapting to changes in temperature,irradiation time and irradiation distance by leveraging the synergy between traps and color centers.展开更多
Lanthanide-based luminescent anticounterfeiting materials are widely used in various kinds of products.At present,the conventional lanthanide-based luminescent anticounterfeiting technique is based on photoluminescenc...Lanthanide-based luminescent anticounterfeiting materials are widely used in various kinds of products.At present,the conventional lanthanide-based luminescent anticounterfeiting technique is based on photoluminescence from ultraviolet light irradiation,resulting in the decreased efficiency of anticounterfeiting applications.In this work,we realized three luminescence modes in a perovskite structure(CaTiO_(3):Pr^(3+),Er^(3+)),in which the excitation-wavelength-dependent photoluminescence(PL)emission,afterglow and upconversion luminescence(UCL)of a doped lanthanide were first presented.Upon ultraviolet excitation,the color of the PL emission can be finely tuned from red to orange,yellow and green by increasing the excitation wavelength from 365 nm to 380 nm.The doped lanthanide emits an intense green color upon illumination with a 980 nm excitation source and a long persisting red color(612 nm)when a UV lamp at 365 nm excitation is switched off.Based on the above luminescence modes of CaTiO_(3):Pr^(3+),Er^(3+),a multilevel anticounterfeiting quick response code(QR code)was developed.The QR code readily integrates the advantages of the excitation wavelength-dependent PL emissions,a strong red afterglow and sensitive excitation power-dependent UCL emissions in one overall device.The presented multilevel anticounterfeiting strategies may inspire the resolution of counterfeit issues in various fields.展开更多
Multicolor and multimodal luminescence materials play crucial roles in anti-counterfeiting and encryption technologies due to their attractive properties of colorful,visually identifiable emissions and distinct emissi...Multicolor and multimodal luminescence materials play crucial roles in anti-counterfeiting and encryption technologies due to their attractive properties of colorful,visually identifiable emissions and distinct emission modes in various excitation or stimulus channels.Nevertheless,integrating multicolor and multimodal luminescence via single rare-earth doping based on a single matrix remains a significant challenge.展开更多
To understand the fundamental mechanism of aggregation-induced phosphorescent emission(AIPE)and to improve the development of mechanochromic molecules,five new Pt(II)complexes Pt-1–Pt-5 bearing different terminal sub...To understand the fundamental mechanism of aggregation-induced phosphorescent emission(AIPE)and to improve the development of mechanochromic molecules,five new Pt(II)complexes Pt-1–Pt-5 bearing different terminal substituents on 1,3-di(2-pyridyl)benzene(N^C^N)ligands were designed and synthesized.Their photophysical properties have been investigated systematically via a series of spectroscopic methods.Upon excitation,the solid states of these Pt complexes exhibit tunable emissions from yellow to red,and complexes Pt-2 and Pt-3 with a large steric hindrance display remarkable AIPE properties in a tetrahydrofuran/H_(2)O mixture.All complexes,except Pt-5,show evident mechanochromic and vapochromic behaviors.Based on in-depth experimental studies,the reason for the mechanochromic behavior could be the change in the distance of the neighboring Pt complexes,which causes a switching of the emission state from^(3)π,π*/^(3)MLCT(metal-to-ligand charge transfer)to^(3)MLCT.The above results suggest an example of phosphorescence tuning by a switching of the triplet excited state in the solid state,and provide a mechanism of mechanochromic behavior.Furthermore,complex Pt-2 was used as an emission ink in the field of advanced anti-counterfeiting.展开更多
Luminescent materials play a key role in the field of optical anti-counterfeiting.However,the development of multimode,multi-color dynamic phosphors,making optical anti-counterfeiting more advanced and practical,remai...Luminescent materials play a key role in the field of optical anti-counterfeiting.However,the development of multimode,multi-color dynamic phosphors,making optical anti-counterfeiting more advanced and practical,remains a great challenge.Herein,multimode luminescence(PL,PersL,TL,PSL,and PSPL),dynamic multi-color emission phosphors based on a single CaSb_(2)O_(6)(CSO)host doped with manganese ions were developed and studied in detail for the first time.The partial self-reduction of Mn in the CSO crystal was observed.The self-reduction behavior of Mn could be effectively suppressed by co-doping with La^(3+)ions through unequal substitution of the Ca^(2+)ions.Furthermore,it was found that the multimode and dynamic luminescence properties of the CSO:Mn phosphors could be further modulated by adjusting the La^(3+)doping concentration,which could be used as a new type of anti-counterfeiting materials.Here,a novel four-mode multicolor and dynamic anti-counterfeiting“rose bouquet”pattern was designed,where a portable UV lamp only having two emitting wavelengths(254 and 365 nm)was required to achieve a full anti-counterfeiting effect.This design is low-cost,easy to realize and advanced in terms of functionality,which has great potential for practical applications in the field of optical anticounterfeiting.In addition,its temperature sensor application based on the different thermal-quenching characteristics of Mn2+and Mn4+was also evaluated.展开更多
Here,multimodal fluorescent materials of Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)were synthesized by the traditional high-temperature solid-state reaction method.In this garnet Ca_(3)Al_(2)Ge_(3)O_(12) structure,Mn^(2...Here,multimodal fluorescent materials of Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)were synthesized by the traditional high-temperature solid-state reaction method.In this garnet Ca_(3)Al_(2)Ge_(3)O_(12) structure,Mn^(2+)and Cr^(3+)ions occupy dodecahedral sites(Ca sites)and hexahedral sites(Al sites),and can produce dynamic colortunable persistent luminescence at different concentrations,different excitations,and different temperatures;in particular,continuous luminescence with temperature(300 K–473 K)shows a color change from green to deep red.Through detailed pyrolysis studies and theoretical calculations,it is demonstrated that the double-trap structure existing in the host makes the persistent luminescence color temperaturedependent.Anti-counterfeiting and industrial inspection molds were successfully accomplished,which means Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)may be used in anti-counterfeiting and industrial inspection.展开更多
Advanced anti-counterfeiting materials have great research significance in the fields of economy,safety and human health.Compared with independent color mixed anti-counterfeiting materials,ultraviolet(UV)excitation wa...Advanced anti-counterfeiting materials have great research significance in the fields of economy,safety and human health.Compared with independent color mixed anti-counterfeiting materials,ultraviolet(UV)excitation wavelength-dependent discoloration,which can realize the change of the emission peak shape and color under different excitation wavelengths,is more attractive.展开更多
Dynamic room-temperature phosphorescence(RTP)materials with color-tunable afterglow characteristics hold great promise for advanced anti-counterfeiting and multidimensional encryption applications.In this work,we succ...Dynamic room-temperature phosphorescence(RTP)materials with color-tunable afterglow characteristics hold great promise for advanced anti-counterfeiting and multidimensional encryption applications.In this work,we successfully synthesized a novel two-dimensional phenylammonium cadmium chloride perovskite(B-PACC)with enhanced RTP efficiency via boronic acid group-assisted crystallization.Furthermore,a precise doping strategy was employed to introduce Mn^(2+),which assembled into Mn^(2+)pairs forming a Mn^(2+)-based inorganic layer.This layer,together with B-PACC,constructed a heterojunction structure with different interlayer spacings,enabling dynamic afterglow emission color modulation from red to blue.Moreover,tuning the Mn^(2+)concentration enables precise modulation of the energy transfer rates from the singlet and triplet states of the organic moieties to the Mn^(2+)layer,thereby allowing fine control over the dynamic RTP behavior.Benefiting from the minimal background interference and large chromaticity contrast associated with the red-to-blue phosphorescence transition,the system exhibited high visual detectability.Based on this dynamic afterglow behavior,we successfully developed time-resolved anti-counterfeiting patterns and constructed dynamic room-temperature phosphorescence-based four-dimensional(4D)codes,providing new insights into the design of dynamic RTP materials and highly secure encryption strategies.展开更多
The growing issue of counterfeiting has driven an increasing demand for advanced anti-counterfeiting technologies.Stepwise structural transformations among numerous compounds offer a promising approach to achieving hi...The growing issue of counterfeiting has driven an increasing demand for advanced anti-counterfeiting technologies.Stepwise structural transformations among numerous compounds offer a promising approach to achieving high-level anti-counterfeiting methods,such as multi-step and time-resolved techniques.However,research in this area is still in its early stages.In this work,we report the first example of the stepwise structural transformation from ASbX_(4)(A=cation,X=halide)to A_(2)SbX_(5) and further to A_(3)SbX_(6).The compounds are[Bzmim]_(4)[Sb_(4)Cl_(16)](1,Bzmim=1-benzyl-3-methylimidazolium),[Bzmim]_(2)SbC_(l5)(2)and[Bzmim]_(3)SbC_(l6)(3).1,2,and 3 exhibit distinct photoluminescent properties:nonemission,red emission peaking at 600 nm,and green emission peaking at 525 nm,respectively.Consequently,stepwise structural transformations enable stepwise luminescent switching from an“off”to multi-“on”states.Moreover,the switching mode can be adjusted from“off-on”to“off-on1-on2”by simply changing the reactant ratio.Using SbCl3 ethanol solutions as invisible ink,multi-step and time-resolved information encryption and anti-counterfeiting were demonstrated by combining[Bzmim]Cl solution,UV light,time,and temperature as developers.The tunable composition and photoluminescent response modes of these IOMHs position them as excellent candidates for high-level information encryption and anti-counterfeiting applications.This work sheds light on the potential for developing advanced informational encryption technologies.展开更多
The development of multicolor emissions in a single phosphor poses a significant challenge with practical implications for high-security-level multi-mode anti-counterfeiting.Herein,a novel Gd_(3)GaO_(6):Bi^(3+),Er^(3+...The development of multicolor emissions in a single phosphor poses a significant challenge with practical implications for high-security-level multi-mode anti-counterfeiting.Herein,a novel Gd_(3)GaO_(6):Bi^(3+),Er^(3+)phosphor with multicolor emissions was successfully prepared and its structural and luminescence properties were investigated.In Bi^(3+)-doped phosphors,the Bi^(3+)ions occupy two different Gd^(3+)sites and exhibit blue-violet light at 409 nm and orange emission at 594 nm,respectively.Besides,Er^(3+)-doped phosphors show green downshifting luminescence under the excitation of 378 nm,green upconversion luminescence under the excitation of 980 nm,and yellow upconversion luminescence under the excitation of 1530 nm.The Gd3GaO6:Bi^(3+),Er^(3+)phosphor displays the emissions of both Bi^(3+)and Er^(3+)under the specific excitation wavelengths.On this basis,a quad-mode anti-counterfeiting material with high security levels has been designed and manufactured,and different luminescence patterns can be obtained under the excitations of 302,365,980 and 1530 nm.This work not only presents a well-performing phosphor for advanced anti-counterfeiting,but also paves the way for designing multicolor emission in one phosphor.展开更多
Persistent luminescent phosphors(PLPs)have attracted much attention in anti-counterfeiting,biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence(PersL)after excitati...Persistent luminescent phosphors(PLPs)have attracted much attention in anti-counterfeiting,biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence(PersL)after excitation ceases.However,most of the PLPs developed so far have only one PersL emission peak,which limits their application in advanced anti-counterfeiting and precise biosensing.Here,a series of dual-emissive Zn_(2)GeO_(4):x%Tb^(3+)/y%Bi^(3+)PLPs was prepared by codoping Tb^(3+)ions and Bi^(3+)ions to significantly improve the trap depth and trap density,resulting in a 16.8-fold increase in PersL intensity compared to the Zn_(2)GeO_(4) host.The photoluminescence(PL)color was adjusted to pale blue under 254 nm UV excitation by trap depth engineering,while the PersL color was green,and the PL color under 365 nm UV excitation was yellow.In addition,the PersL intensity was dramatically increased by 16.8 times by codoping Tb^(3+)and Bi^(3+).Therefore,multi-mode anti-counterfeiting was achieved by multi-stimulus response.Furthermore,the dual-emission band was designed as a ratiometric PersL aptasensor for the detection of mucin 1.The detection linearity ranged from 0.1 to 100 ng mL^(−1) with a detection limit of 0.036 to 1 ng mL^(−1).This novel PLP with a dual-emission band expands the application range of PLPs.展开更多
Recently,persistent luminescence materials(PLMs)have attracted extensive attention in the anti-counterfeiting and information encryption fields.Unfortunately,single visible persistent luminescence(PersL)demonstrates l...Recently,persistent luminescence materials(PLMs)have attracted extensive attention in the anti-counterfeiting and information encryption fields.Unfortunately,single visible persistent luminescence(PersL)demonstrates limited information security because the changes in information coded by visible PersL can be observed by the human eyes.In this work,we develop a dual-mode PLM with ultraviolet(UV)and visible PersL.展开更多
Endowing metal halide hybrids(MHHs)with time-resolved emission and afterglow could significantly broaden their applications in fields such as information security and anti-counterfeiting.Nonetheless,there have been re...Endowing metal halide hybrids(MHHs)with time-resolved emission and afterglow could significantly broaden their applications in fields such as information security and anti-counterfeiting.Nonetheless,there have been relatively few successes in developing organic cations with persistent room-temperature phosphorescence(RTP)to construct MHHs with afterglow.In this work,we synthesize a new polyazole,3,5-di(1H-pyrazol-4-yl)-4H-1,2,4-triazol-4-amine(DPTA),with green persistent RTP up to 1.5 s.The afterglow of DPTA reaches up to∼1.0 s even after being assembled into 0D(DPTAH_(3))InCl_(6)·2.5H_(2)O(DIC).Due to strong overlap between the triplet emission of DPTA and ^(1)S0→^(3)Px absorption of Sb^(3+),efficient triplet energy transfer(TET)with the highest yield of 65.3%and a near-unity photoluminescence quantum yield(PLQY)is achieved.More importantly,the afterglow persistence time of DIC:x%Sb can be easily tailored through Sb^(3+)doping.Given the Sb^(3+)-dependent emission color and long persistence time,a series of DIC:x%Sb are successfully utilized to demonstrate high-security-level anti-counterfeiting application.This work shows an effective strategy for designing new MHHs with tunable emission and afterglow persistence time.展开更多
Zero-dimensional hybrid metal halides(0D HMHs)have sparked extensive research in the field of optoelectronic materials due to their unique physical and chemical properties.This work innovatively incorporates In^(3+)in...Zero-dimensional hybrid metal halides(0D HMHs)have sparked extensive research in the field of optoelectronic materials due to their unique physical and chemical properties.This work innovatively incorporates In^(3+)into a triphenyl-sulfide-based organic phosphorescent system,successfully constructing a novel 0D hybrid metal halide,(Ph_(3)S)_(2)InCl_(5).This new material achieves a synergistic output of blue photoluminescence(PL)and green afterglow,which originate from the intrinsic excitation of[Ph_(3)S]^(+).Through ns^(2) metal ion(Bi^(3+)/Sb^(3+))doping engineering,a dual-channel energy transfer pathway is established,enabling the transition from singlet and triplet states to self-trapped exciton states,thereby achieving dynamic control of fluorescence and phosphorescence emissions.Additionally,temperature-dependent PL spectra,time-resolved photoluminescence(TRPL),and Raman spectroscopy are employed to investigate the enhanced photoluminescence of the doped samples,revealing the process of STE(self-trapped excitons)recombination and the electron–phonon coupling processes.Based on these findings,a phosphorescence-PL dual-mode dynamic switching encryption system is constructed,utilizing a timeresolved multi-level decryption strategy to achieve high-order optical anti-counterfeiting.This work not only aids in the in-depth understanding of STE formation in In-based organic metal halides but also provides important guidance for the modulation strategy of STE and afterglow emissions in other 0D HMH luminescent materials.展开更多
文摘Counterfeiting is one of the most serious problems in the consumer market. One promising approach for anti-counterfeiting is to attach a low-cost Radio-frequency Identification (RFID) tag to the product authentication. In this paper, we propose an RFID system for detecting counterfeiting products. This RFID system consists of the tag authentication protocol and the database correction protocol. We use the tag authentication protocol for authenticating tags without revealing their sensitive information. This protocol also allows the customer to freely inquire the tag. To prevent the widespread of the counterfeit products, we use the tag status information along with tag identity information. Meanwhile, the database correction protocol guarantees the correctness of the tag status. Our anti-counterfeiting system is the first work considering the seller who plays an important role in the consumer product supply chain. Finally, we show that anti-counterfeiting system is quite secure against counterfeiting and the tag authentication protocol is lightweight enough to be implemented in RFID-based applications.
基金Project(51874129)supported by the National Natural Science Foundation of ChinaProjects(2018JJ3115,2019JJ60049)supported by the Science Foundation of Hunan Province,ChinaProjects(19B153,19B158)supported by the Scientific Research Fund of Hunan Provincial Education Department,China。
文摘Novel hydrophilic NaYF4:Yb^3+,Tm^3+@NaGdF4:Ce^3+,Eu^3+double-jacket microtubes(DJMTs)with upconversion/downconversion dual-mode luminescence were designed and prepared through epitaxial growth of NaGdF4:Ce^3+,Eu^3+shell onto the NaYF4:Yb^3+,Tm^3+microtube via poly(acrylic acid)(PAA)mediated hydrothermal method.It is demonstrated that PAA ligand played an important role in guiding the direct growth of NaGdF4:Ce^3+,Eu^3+shell onto the surface of NaYF4:Yb^3+,Tm^3+parent microtubes.The growth of NaGdF4:Ce^3+,Eu^3+shell experienced a crystal phase transition fromβ-NaGdF4 andβ-NaYF4 mixture toβ-NaYF4@NaGdF4 composite crystal,and morphology evolution from mixture ofβ-NaGdF4:Ce^3+,Eu^3+nanorods andβ-NaYF4:Yb^3+,Tm^3+microtubes to NaYF4:Yb^3+,Tm^3+@NaGdF4:Ce^3+,Eu^3+DJMTs.The formation mechanism of DJMTs was the dissolution−renucleation ofβ-NaGdF4:Ce^3+,Eu^3+nanorods and the growth ofβ-NaGdF4:Ce^3+,Eu^3+shell via the classical Ostwald ripening mechanism.The as-prepared DJMTs could exhibit blue upconversion and red downconversion luminescence,which was further made into environmentally benign luminescent inks for creating highly secured and fluorescent-based anti-counterfeiting patterns via inkjet printing.
文摘Pharmaceutical counterfeiting is a health scourge responsible for several cases of morbidity and mortality. Counterfeit medicines cause therapeutic failure, emergence of resistance in the treatment of infections. This study was conducted in order to identify counterfeit and authentic medicines in circulation in Lubumbashi. The study included artemether and artesunate for oral administration. A careful visual inspection of medicine, investigation of authenticity of pharmaceutical products from manufacturers and pharmaceutical regulatory authorities and determination of content were used as study parameters. 52 samples: 37 artemether and 15 of artésunate were collected. 7 samples (13%) have proven to be counterfeit. Artemether was the most counterfeit (71%) and 29% for artesunate. 6 (12%) samples were substandard according to the international pharmacopoeia in terms of content of active ingredient. Sixty-seven percent of non-compliance concerned counterfeit medicines. The proportion of non-compliance is highest among counterfeit medicines (71.43% vs 2.22%;p = 0.000004). It is obvious that strengthening the capacity of the drug regulatory authority of the DRC reduces the influx of counterfeit drug and substandard.
文摘February-15,virtual ITU is organizing a series of webinars on Combating counterfeiting and stolen information and communications technology(ICT)devices.The Episode 1:"Existing challenges and solutions on combating counterfeiting of ICT devices",will take place fully virtually on 15 February 2023.
基金supported by the National Key R&D Program of China(2023YFA1406200)the National Natural Science Foundation of China(T2521005,12174144,12474009,12174146,and 124B2059)the Special Construction Project Fund for Shan-dong Province Taishan Scholars.
文摘Multifunctional optical responsive materials have grown increasingly pivotal in addressingthe escalating demands of sensing,detection,and anti-counterfeiting applications[1,2].These materials exhibit distinct visible optical variations upon exposure to external stimuli,such as pressure,temperature,light,solvents,pH fluctuations,or mechanical force.Fluorescent sensing and anti-counterfeiting technologies leveraging these optical responses have emerged as highly promising solutions.
基金supported by the National Natural Science Foundation of China(nos.22125201,22532003,and 22405014)the China Post-Doctoral Science Foundation(no.2023 M740182)Suzhou Key Laboratory of Bio-Inspired Interfacial Science(SZ2024004).
文摘Highly ordered films of polystyrene(PS)micro-spheres have demonstrated various merits in optoelectronic devices,given their size-and thickness-dependent optical properties.So far,various solution strategies have been developed for making such highly ordered films,which have suffered from the lack of precise control on the film thickness(i.e.,layer number of micro-spheres).Here,we developed a facile fibrous liquid bridge strategy for fabricating highly ordered PS micro-sphere films,featured as the finely tunable mono-to multi-layer.Guided by a horizontally placed fiber with both ends passing through a capillary tube,respectively,the solution was transferred steadily onto the target substrate forming a homogeneous liquid film,whose dewetting process thus confines the assembly ofmicro-spheres in a well-controllablemanner.Depending on both the solution-shearing speed and the local concentration,a dynamic equilibrium between liquid transfer and evaporation was realized,which enables the formation of highly ordered micro-sphere films with finely tunable layer numbers.We demonstrated the angle-specific information encryption for anti-counterfeiting by utilizing patterned PS micro-sphere films that modulate structural colors based on layer-dependent optical responses.The result offers a new perspective for fabricating highly ordered film with tunable layers.
基金supported by the National Natural Science Foundation of China(Grant No.52072364 and 22175169)Program of Science and Technology Development Plan,Jilin Province,China(YDZJ202302CXJD065).
文摘Developing advanced fluorescence anti-counterfeiting technologies can enhance the effectiveness of current anti-counterfeiting strategies by addressing their limitations.To meet this demand,an afterglow material Y_(2)CaSnGa_(4)O_(12):Pr^(3+)(YCSG:Pr^(3+))exhibiting photochromic phenomena was engineered.This design capitalizes on the opposite effects of traps and color centers on emission intensity,thus ingeniously achieving excitation wavelength-dependent modifications in luminescence intensity.A thorough analysis of the energy conversion processes before and after irradiation by ultraviolet light was undertaken to discern the dominant role of color centers and traps under varying excitation conditions.Thereby,the dynamic energy conversion processes from traps and color centers to the luminescence center are established,showing a variety of output modes related to wavelength,irradiation time and distance.Furthermore,discrepancies in energy transfer efficiency from traps to different energy levels result in temperature-dependent spectral variations,consequently manifesting distinct colors in afterglow and luminescence at each temperature.This pioneering approach serves as a valuable blueprint for the development of multimode dynamic anti-counterfeiting materials capable of adapting to changes in temperature,irradiation time and irradiation distance by leveraging the synergy between traps and color centers.
基金financial support from the National Natural Science Foundation of China(Grant No.21871122 and 21431002)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2020-kb13).
文摘Lanthanide-based luminescent anticounterfeiting materials are widely used in various kinds of products.At present,the conventional lanthanide-based luminescent anticounterfeiting technique is based on photoluminescence from ultraviolet light irradiation,resulting in the decreased efficiency of anticounterfeiting applications.In this work,we realized three luminescence modes in a perovskite structure(CaTiO_(3):Pr^(3+),Er^(3+)),in which the excitation-wavelength-dependent photoluminescence(PL)emission,afterglow and upconversion luminescence(UCL)of a doped lanthanide were first presented.Upon ultraviolet excitation,the color of the PL emission can be finely tuned from red to orange,yellow and green by increasing the excitation wavelength from 365 nm to 380 nm.The doped lanthanide emits an intense green color upon illumination with a 980 nm excitation source and a long persisting red color(612 nm)when a UV lamp at 365 nm excitation is switched off.Based on the above luminescence modes of CaTiO_(3):Pr^(3+),Er^(3+),a multilevel anticounterfeiting quick response code(QR code)was developed.The QR code readily integrates the advantages of the excitation wavelength-dependent PL emissions,a strong red afterglow and sensitive excitation power-dependent UCL emissions in one overall device.The presented multilevel anticounterfeiting strategies may inspire the resolution of counterfeit issues in various fields.
基金supported by the National Natural Science Foundation of China(Grant No.21871122 and 21431002)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021-kb17).
文摘Multicolor and multimodal luminescence materials play crucial roles in anti-counterfeiting and encryption technologies due to their attractive properties of colorful,visually identifiable emissions and distinct emission modes in various excitation or stimulus channels.Nevertheless,integrating multicolor and multimodal luminescence via single rare-earth doping based on a single matrix remains a significant challenge.
基金support pro-vided in part by the Natural Science Foundation of Jiangsu Province-Outstanding Youth Foundation(BK20170104)the National Natural Science Foundation of China(21602106)+2 种基金the Six Talent Peaks Project in Jiangsu Province(XCL-037)the Strategic Pioneer Program on Space Science,Chinese Academy of Sciences(XDA15013100 and XDA15013101)the Undergraduate Innovation and Entrepreneurship Training Program(201910291053Z).
文摘To understand the fundamental mechanism of aggregation-induced phosphorescent emission(AIPE)and to improve the development of mechanochromic molecules,five new Pt(II)complexes Pt-1–Pt-5 bearing different terminal substituents on 1,3-di(2-pyridyl)benzene(N^C^N)ligands were designed and synthesized.Their photophysical properties have been investigated systematically via a series of spectroscopic methods.Upon excitation,the solid states of these Pt complexes exhibit tunable emissions from yellow to red,and complexes Pt-2 and Pt-3 with a large steric hindrance display remarkable AIPE properties in a tetrahydrofuran/H_(2)O mixture.All complexes,except Pt-5,show evident mechanochromic and vapochromic behaviors.Based on in-depth experimental studies,the reason for the mechanochromic behavior could be the change in the distance of the neighboring Pt complexes,which causes a switching of the emission state from^(3)π,π*/^(3)MLCT(metal-to-ligand charge transfer)to^(3)MLCT.The above results suggest an example of phosphorescence tuning by a switching of the triplet excited state in the solid state,and provide a mechanism of mechanochromic behavior.Furthermore,complex Pt-2 was used as an emission ink in the field of advanced anti-counterfeiting.
文摘Luminescent materials play a key role in the field of optical anti-counterfeiting.However,the development of multimode,multi-color dynamic phosphors,making optical anti-counterfeiting more advanced and practical,remains a great challenge.Herein,multimode luminescence(PL,PersL,TL,PSL,and PSPL),dynamic multi-color emission phosphors based on a single CaSb_(2)O_(6)(CSO)host doped with manganese ions were developed and studied in detail for the first time.The partial self-reduction of Mn in the CSO crystal was observed.The self-reduction behavior of Mn could be effectively suppressed by co-doping with La^(3+)ions through unequal substitution of the Ca^(2+)ions.Furthermore,it was found that the multimode and dynamic luminescence properties of the CSO:Mn phosphors could be further modulated by adjusting the La^(3+)doping concentration,which could be used as a new type of anti-counterfeiting materials.Here,a novel four-mode multicolor and dynamic anti-counterfeiting“rose bouquet”pattern was designed,where a portable UV lamp only having two emitting wavelengths(254 and 365 nm)was required to achieve a full anti-counterfeiting effect.This design is low-cost,easy to realize and advanced in terms of functionality,which has great potential for practical applications in the field of optical anticounterfeiting.In addition,its temperature sensor application based on the different thermal-quenching characteristics of Mn2+and Mn4+was also evaluated.
基金supported by the National Natural Science Foundation of China(No.51902080)the central government to guide local scientific and Technological Development(No.206Z1102G and 216Z1101G)Post-graduate’s Innovation Fund Project of Hebei University(HBU2022bs014).
文摘Here,multimodal fluorescent materials of Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)were synthesized by the traditional high-temperature solid-state reaction method.In this garnet Ca_(3)Al_(2)Ge_(3)O_(12) structure,Mn^(2+)and Cr^(3+)ions occupy dodecahedral sites(Ca sites)and hexahedral sites(Al sites),and can produce dynamic colortunable persistent luminescence at different concentrations,different excitations,and different temperatures;in particular,continuous luminescence with temperature(300 K–473 K)shows a color change from green to deep red.Through detailed pyrolysis studies and theoretical calculations,it is demonstrated that the double-trap structure existing in the host makes the persistent luminescence color temperaturedependent.Anti-counterfeiting and industrial inspection molds were successfully accomplished,which means Ca_(3)Al_(2)Ge_(3)O_(12):Mn^(2+),Cr^(3+)may be used in anti-counterfeiting and industrial inspection.
基金supported by the Educational Committee of Hebei Province(No.ZD2017214).
文摘Advanced anti-counterfeiting materials have great research significance in the fields of economy,safety and human health.Compared with independent color mixed anti-counterfeiting materials,ultraviolet(UV)excitation wavelength-dependent discoloration,which can realize the change of the emission peak shape and color under different excitation wavelengths,is more attractive.
基金supported by Foundation of Graphene Powder&Composite Research Centre of Fujian Province(No.2017H_(2)001)Pilot Project of Fujian Province(No.2021H0017).
文摘Dynamic room-temperature phosphorescence(RTP)materials with color-tunable afterglow characteristics hold great promise for advanced anti-counterfeiting and multidimensional encryption applications.In this work,we successfully synthesized a novel two-dimensional phenylammonium cadmium chloride perovskite(B-PACC)with enhanced RTP efficiency via boronic acid group-assisted crystallization.Furthermore,a precise doping strategy was employed to introduce Mn^(2+),which assembled into Mn^(2+)pairs forming a Mn^(2+)-based inorganic layer.This layer,together with B-PACC,constructed a heterojunction structure with different interlayer spacings,enabling dynamic afterglow emission color modulation from red to blue.Moreover,tuning the Mn^(2+)concentration enables precise modulation of the energy transfer rates from the singlet and triplet states of the organic moieties to the Mn^(2+)layer,thereby allowing fine control over the dynamic RTP behavior.Benefiting from the minimal background interference and large chromaticity contrast associated with the red-to-blue phosphorescence transition,the system exhibited high visual detectability.Based on this dynamic afterglow behavior,we successfully developed time-resolved anti-counterfeiting patterns and constructed dynamic room-temperature phosphorescence-based four-dimensional(4D)codes,providing new insights into the design of dynamic RTP materials and highly secure encryption strategies.
基金financial supports from the National Nature Science Foundation of China(No.22205236 and 92261115)the Natural Science Foundation of Fujian Province(No.2022J05089).
文摘The growing issue of counterfeiting has driven an increasing demand for advanced anti-counterfeiting technologies.Stepwise structural transformations among numerous compounds offer a promising approach to achieving high-level anti-counterfeiting methods,such as multi-step and time-resolved techniques.However,research in this area is still in its early stages.In this work,we report the first example of the stepwise structural transformation from ASbX_(4)(A=cation,X=halide)to A_(2)SbX_(5) and further to A_(3)SbX_(6).The compounds are[Bzmim]_(4)[Sb_(4)Cl_(16)](1,Bzmim=1-benzyl-3-methylimidazolium),[Bzmim]_(2)SbC_(l5)(2)and[Bzmim]_(3)SbC_(l6)(3).1,2,and 3 exhibit distinct photoluminescent properties:nonemission,red emission peaking at 600 nm,and green emission peaking at 525 nm,respectively.Consequently,stepwise structural transformations enable stepwise luminescent switching from an“off”to multi-“on”states.Moreover,the switching mode can be adjusted from“off-on”to“off-on1-on2”by simply changing the reactant ratio.Using SbCl3 ethanol solutions as invisible ink,multi-step and time-resolved information encryption and anti-counterfeiting were demonstrated by combining[Bzmim]Cl solution,UV light,time,and temperature as developers.The tunable composition and photoluminescent response modes of these IOMHs position them as excellent candidates for high-level information encryption and anti-counterfeiting applications.This work sheds light on the potential for developing advanced informational encryption technologies.
基金financially supported by the National Key Research and Development Program(Grant No.2022YFC2905201)the National Natural Science Foundation of China(Grant No.52072363)the Research Project of Ganjiang Innovation Academy,Chinese Academy of Sciences(E255C001).
文摘The development of multicolor emissions in a single phosphor poses a significant challenge with practical implications for high-security-level multi-mode anti-counterfeiting.Herein,a novel Gd_(3)GaO_(6):Bi^(3+),Er^(3+)phosphor with multicolor emissions was successfully prepared and its structural and luminescence properties were investigated.In Bi^(3+)-doped phosphors,the Bi^(3+)ions occupy two different Gd^(3+)sites and exhibit blue-violet light at 409 nm and orange emission at 594 nm,respectively.Besides,Er^(3+)-doped phosphors show green downshifting luminescence under the excitation of 378 nm,green upconversion luminescence under the excitation of 980 nm,and yellow upconversion luminescence under the excitation of 1530 nm.The Gd3GaO6:Bi^(3+),Er^(3+)phosphor displays the emissions of both Bi^(3+)and Er^(3+)under the specific excitation wavelengths.On this basis,a quad-mode anti-counterfeiting material with high security levels has been designed and manufactured,and different luminescence patterns can be obtained under the excitations of 302,365,980 and 1530 nm.This work not only presents a well-performing phosphor for advanced anti-counterfeiting,but also paves the way for designing multicolor emission in one phosphor.
基金supported by the National Natural Science Foundation of China(62105333)the Natural Science Foundation of Xiamen,China(3502Z20227253)+1 种基金the Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2020ZZ114 Z).
文摘Persistent luminescent phosphors(PLPs)have attracted much attention in anti-counterfeiting,biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence(PersL)after excitation ceases.However,most of the PLPs developed so far have only one PersL emission peak,which limits their application in advanced anti-counterfeiting and precise biosensing.Here,a series of dual-emissive Zn_(2)GeO_(4):x%Tb^(3+)/y%Bi^(3+)PLPs was prepared by codoping Tb^(3+)ions and Bi^(3+)ions to significantly improve the trap depth and trap density,resulting in a 16.8-fold increase in PersL intensity compared to the Zn_(2)GeO_(4) host.The photoluminescence(PL)color was adjusted to pale blue under 254 nm UV excitation by trap depth engineering,while the PersL color was green,and the PL color under 365 nm UV excitation was yellow.In addition,the PersL intensity was dramatically increased by 16.8 times by codoping Tb^(3+)and Bi^(3+).Therefore,multi-mode anti-counterfeiting was achieved by multi-stimulus response.Furthermore,the dual-emission band was designed as a ratiometric PersL aptasensor for the detection of mucin 1.The detection linearity ranged from 0.1 to 100 ng mL^(−1) with a detection limit of 0.036 to 1 ng mL^(−1).This novel PLP with a dual-emission band expands the application range of PLPs.
基金supported by the National Natural Science Foundation of China(61705228 and 62105333)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2020ZZ114).
文摘Recently,persistent luminescence materials(PLMs)have attracted extensive attention in the anti-counterfeiting and information encryption fields.Unfortunately,single visible persistent luminescence(PersL)demonstrates limited information security because the changes in information coded by visible PersL can be observed by the human eyes.In this work,we develop a dual-mode PLM with ultraviolet(UV)and visible PersL.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2022A1515011997)the Li Ka Shing Foundation Cross-Disciplinary Research Project(2020LKSFG09A)+2 种基金the Open Foundation of Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials(2022GXYSOF14)K.X.is thankful for the financial support from the National Natural Science Foundation of China(52203343)the Shenzhen Science and Technology Program(20210607151625001).
文摘Endowing metal halide hybrids(MHHs)with time-resolved emission and afterglow could significantly broaden their applications in fields such as information security and anti-counterfeiting.Nonetheless,there have been relatively few successes in developing organic cations with persistent room-temperature phosphorescence(RTP)to construct MHHs with afterglow.In this work,we synthesize a new polyazole,3,5-di(1H-pyrazol-4-yl)-4H-1,2,4-triazol-4-amine(DPTA),with green persistent RTP up to 1.5 s.The afterglow of DPTA reaches up to∼1.0 s even after being assembled into 0D(DPTAH_(3))InCl_(6)·2.5H_(2)O(DIC).Due to strong overlap between the triplet emission of DPTA and ^(1)S0→^(3)Px absorption of Sb^(3+),efficient triplet energy transfer(TET)with the highest yield of 65.3%and a near-unity photoluminescence quantum yield(PLQY)is achieved.More importantly,the afterglow persistence time of DIC:x%Sb can be easily tailored through Sb^(3+)doping.Given the Sb^(3+)-dependent emission color and long persistence time,a series of DIC:x%Sb are successfully utilized to demonstrate high-security-level anti-counterfeiting application.This work shows an effective strategy for designing new MHHs with tunable emission and afterglow persistence time.
基金the financial support from the Heilongjiang Provincial Key Laboratory of Micro-nano Sensitive Devices and Systems(Heilongjiang University)the Basic Research Project for Outstanding Young Teachers of Heilongjiang Province(YQJH2023128)the Cultivation Project of Double First-class Initiative Discipline by Heilongjiang Province(LJGXCG2022-061).
文摘Zero-dimensional hybrid metal halides(0D HMHs)have sparked extensive research in the field of optoelectronic materials due to their unique physical and chemical properties.This work innovatively incorporates In^(3+)into a triphenyl-sulfide-based organic phosphorescent system,successfully constructing a novel 0D hybrid metal halide,(Ph_(3)S)_(2)InCl_(5).This new material achieves a synergistic output of blue photoluminescence(PL)and green afterglow,which originate from the intrinsic excitation of[Ph_(3)S]^(+).Through ns^(2) metal ion(Bi^(3+)/Sb^(3+))doping engineering,a dual-channel energy transfer pathway is established,enabling the transition from singlet and triplet states to self-trapped exciton states,thereby achieving dynamic control of fluorescence and phosphorescence emissions.Additionally,temperature-dependent PL spectra,time-resolved photoluminescence(TRPL),and Raman spectroscopy are employed to investigate the enhanced photoluminescence of the doped samples,revealing the process of STE(self-trapped excitons)recombination and the electron–phonon coupling processes.Based on these findings,a phosphorescence-PL dual-mode dynamic switching encryption system is constructed,utilizing a timeresolved multi-level decryption strategy to achieve high-order optical anti-counterfeiting.This work not only aids in the in-depth understanding of STE formation in In-based organic metal halides but also provides important guidance for the modulation strategy of STE and afterglow emissions in other 0D HMH luminescent materials.
