Biological Interaction and Imaging of Ultrasmall Gold Nanoparticles

Ultrasmall gold nanoparticles(AuNPs)typically includes atomically precise gold nanoclusters(AuNCs)and AuNPs with a core size below 3 nm.Serving as a bridge between small molecules and traditional inorganic nanoparticles,the ultrasmall AuNPs show the unique advantages of both small molecules(e.g.,rapid distribution,renal clearance,low non-specific organ accumulation)and nanoparticles(e.g.,long blood circulation and enhanced permeability and retention effect).The emergence of ultrasmall AuNPs creates significant opportunities to address many challenges in the health field including disease diagnosis,monitoring and treatment.Since the nano–bio interaction dictates the overall biological applications of the ultrasmall AuNPs,this review elucidates the recent advances in the biological interactions and imaging of ultrasmall AuNPs.We begin with the introduction of the factors that influence the cellular interactions of ultrasmall AuNPs.We then discuss the organ interactions,especially focus on the interactions of the liver and kidneys.We further present the recent advances in the tumor interactions of ultrasmall AuNPs.In addition,the imaging performance of the ultrasmall AuNPs is summarized and discussed.Finally,we summarize this review and provide some perspective on the future research direction of the ultrasmall AuNPs,aiming to accelerate their clinical translation.

Cu,N codoped carbon nanosheets encapsulating ultrasmall Cu nanoparticles for enhancing selective 1,2-propanediol oxidation

In the selective oxidation of biomass-based 1,2-propanediol(PDO)with oxygen as the terminal oxidant,it is challenging to improve the lactic acid(LA)selectivity for nonnoble metal nanoparticles(NPs)due to their limited oxygen reduction rate and easy C-C cleavage.Given the high economic feasibility of nonnoble metals,i.e.,Cu,in this work,copper and nitrogen codoped porous carbon nanosheets encapsulating ultrafine Cu nanoparticles(Cu@Cu-N-C)were developed to realize highly selective of PDO oxidation to LA.The carbon-encapsulated ultrasmall Cu^(0)NPs in Cu@Cu-N-C have high PDO dehydrogenation activity while N-coordinated Cu(Cu-N)sites are responsible for the high oxygen reduction efficacy.Therefore,the performance of catalytic PDO conversion to LA is optimized by a proposed pathway of PDO→hydroxylacetone→lactaldehyde→LA.Specifically,the enhanced LA selectivity is 88.5%,and the PDO conversion is up to 75.1%in an O_(2)-pressurized reaction system(1.0 MPa O_(2)),superior to other Cu-based catalysts,while in a milder nonpressurized system(O_(2)flow rate of 100 mL min-1),a remarkable LA selectivity(94.2%)is obtained with 39.8%PDO conversion,2.2 times higher than that of supported Au nanoparticles(1%Au/C).Moreover,carbon encapsulation offers Cu@Cu-N-C with strong leaching resistance for better recycling.

Ultrasmall pH-responsive silicon phthalocyanine micelle for selective photodynamic therapy against tumo

Targeted photodynamic therapy(TPDT)based on the photosensitizers responsive for tumor micr oenvironment is promising because of the better anti-tumor effect and less phototoxicity against normal tissue than the traditional PDT.Nanoparticle based stimuli responsive photo-sensitizers have been widely explored for TPDT.Based on the acidic microenvironments in solid tumors,an ultrasmall pH-responsive silicon phthalocyanine nanomicelle(PSN)(smaller than 10 nm)was designed for selective PDT of tumor.PSN had high drug loading efficacy(more than 28%)and exhibited morphological transitions,enhanced fuorescence and improved singlet∞x-ygen yield under acidic environments.PSN was renal dlearable and could rapidly accumulate and be retained at tumor sites,achieving a tumor-inhibiting ffect better than phthalocyanine micelle without pH response.Tumors of mice treated with PSN for PDT were completely ablated without recurrence.Thus,we have developed a phthalocyanine-based pH responsive micelle with excellent tumor targeting ability,which is expected to realize the selective PDT of tumor.

Measurements of Sulfur Isotope Composition on Ultrasmall(80 Nanomole) Sulfide and Sulfate Samples by a Modified EA-IRMS

The traditional method for sulfur isotope measurement using EA-IRMS commonly requires sulfur content greater than 2 μmol. Such a large sample size limits its application to low-S materials, the size mainly being due to ineffective utilization of sample gas, almost 99.7% of which is discarded with carrier gas through the split port of the continuous-flow interface. A modified EA-IRMS system with a gas chromatographic(GC) column and a custom-built cryogenic concentration device is used in this study. We measured six reference materials to test the performance of this method. The results were consistent with those obtained through traditional EA-IRMS. Precisions ranging from ±0.24‰ to ±0.76‰(1σ)can be obtained with samples equivalent to ~80 nmol sulfur, which were similar to results obtained from an alternative method using an absorption column. Our improved method is a powerful tool for sulfur isotope measurement in ultrasmall sulfide and sulfate samples, which can be further applied to carbon, nitrogen and oxygen isotope analyses of samples at about 100 nmol level.

Low-temperature synthesis of ultrasmall spinel MnxCo3-xO4 nanoparticles for efficient oxygen reduction

Spinel-type manganese-cobalt oxides have been regarded as important class of electrocatalysts for oxygen reduction reaction(ORR).However,they are usually synthesized through oxidation-precipitation under aqueous ammonia and then crystallization at high temperature(150–180℃),which not only increases the energy consumption but also induces the growth of particles that is unfavorable for ORR.Herein,through a facile precipitation-dehydration method,ultrasmall spinel manganese-cobalt oxide nanoparticles(~5 nm)homogeneously dispersed on conductive carbon black(MnxCo3-xO4/C)were fabricated at low temperature(60℃).And the bimetallic composite oxide(Mn1.5Co1.5O4/C)with cubic spinel structure and high Mn content exhibits remarkable enhancement of ORR activity and stability compared with single metal oxide(both Mn3O4/C and Co3O4/C).The essential reason for the enhancement of activity can be attributed to the presence of the mixed Mn^3+ and Mn^4+ cations in Mn1.5Co1.5O4/C.Moreover,the ORR activity of Mn1.5Co1.5O4/C is comparable to that of commercial 20 wt% Pt/C,and the relative current density only decreases 1.4% after 12 h test,exceeding that of Pt/C and most reported manganese-cobalt oxide electrocatalysts.

Oxygen Electroreduction Performance of Ultrasmall Gold Nanoclusters

Ultrasmall gold nanoclusters consisting of 2-4 Au atoms were synthesized and their per- formance in electrocatalytic oxygen reduction reactions （ORR） was examined. These clus- ters were synthesized by exposing AuPPh3Cl to the aqueous ammonia medium for one week. Electrospray ionization mass spectrometry （ESI-MS）, X-ray absorption fihe struc- ture （XAFS）, and X-ray photoelectron spectroscopy （XPS） analyses indicate that the as- synthesized gold clusters （abbreviated as Aux） consist of 2-4 Au atoms coordinated by the triphenylphosphine, hydroxyl, and adsorbed oxygen ligands. A glassy carbon disk electrode loaded with the Aux clusters （Aux/GC） was characterized by the cyclic and linear-sweep voltammetry for ORR. The cyclic voltammogram vs. RHE shows the onset potential of 0.87 V, and the kinetic parameters of JK at 0.47 V and the electron-transfer mmlber per oxygen molecule were calculated to be 14.28 mA/cm2 and 3.96 via the Koutecky-Levich equations, respectively.

Ultrasmall high-entropy alloy nanoparticles on hierarchical N-doped carbon nanocages for tremendous electrocatalytic hydrogen evolution

High-entropy alloys (HEAs) are promising candidates for the electrocatalyst of hydrogen evolution reaction (HER) due to their unique properties such as cocktail electronic effect and lattice distortion effect. Herein, the ultrasmall (sub-2 nm) nanoparticles of PtRuCoNiCu HEA with uniform element distribution are highly dispersed on hierarchical N-doped carbon nanocages (hNCNC) via low-temperature thermal reduction, denoted as us-HEA/hNCNC. The optimal us-HEA/hNCNC exhibits excellent HER performance in 0.5 M H_(2)SO4 solution, achieving an ultralow overpotential of 19 mV at 10 mA·cm^(−2) (without iR-compensation), high mass activity of 13.1 A·mgnoble metals ^(−1) at −0.10 V and superb stability with a slight overpotential increase of 3 mV after 20,000 cycles of cyclic voltammetry scans, much superior to the commercial Pt/C (20 wt.%). The combined experimental and theoretical studies reveal that the Pt&Ru serve as the main active sites for HER and the CoNiCu species modify the electron density of active sites to facilitate the H* adsorption and achieve an optimum M-H binding energy. The hierarchical pore structure and N-doping of hNCNC support also play a crucial role in the enhancement of HER activity and stability. This study demonstrates an effective strategy to greatly improve the HER performance of noble metals by developing the HEAs on the unique hNCNC support.

Enhanced electrocatalytic activity of Co@N-doped carbon nanotubes by ultrasmall defect-rich TiO2 nanoparticles for hydrogen evolution reaction

Despite being technically possible, splitting water to generate hydrogen is practically unfeasible, mainly because of the lack of sustainable and efficient earth-abundant catalysts for the hydrogen-evolution reaction （HER）. Herein, we report a durable and highly active electrochemical HER catalyst based on defect-rich TiO2 nanoparticles loaded on Co nanoparticles@N-doped carbon nanotubes （D-TiOdCo@NCT） synthesized by electrostatic spinning and a subsequent calcining process. The ultrasmall TiO2 nanoparticles are 1.5-2 nm in size and have a defect-rich structure of oxygen vacancies. D-TiO2/Co@NCT exhibits excellent HER catalytic activity in an acidic electrolyte （0.5 M H2SO4）, with a low onset potential of -57.5 mV （1 mA·cm^-2）, a small Tafel slope of 73.5 mV·dec^-1, and extraordinary long-term durability. X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and theoretical calculations confirm that the Ti3. defect-rich structure can effectively regulate the catalytic activity for electrochemical water splitting.

Surface curvature-confined strategy to ultrasmall nickel-molybdenum sulfide nanoflakes for highly efficient deep hydrodesulfurization

Size-controlled synthesis of two-dimensional(2D)catalysts with low stacking numbers and small nanoflake lengths is crucial for promoting the catalytic performance in diverse heterogeneous catalysis.Herein,we report a facile and general“surface curvature-confined synthesis”strategy to modulate the slab lengths and stacking numbers of 2D transition metal sulfides by controlling the strain induced by different surface curvature of supports.An efficient NiMo sulfide with shorter slab length(average 3.71 nm),less stacking number(1–2 layers)and more edge active sites is synthesized onto ZSM-5 zeolites with the average size of 100 nm,which shows superior kHDS value of dibenzothiophene(14.05×10^−7 mol/(g·s)),enhanced stability up to 80 h,and high direct desulfurization selectivity(>95%).This design concept is also proved to be generally applicable to modulate the slab lengths and stacking numbers of other 2D catalysts such as MoS2 and WS2 nanoflakes,which shows great potentials for developing more ultrasmall 2D catalysts with controlled sizes and excellent catalytic activities.

Confinement and antenna effect for ultrasmall Y_(2)O_(3):Eu^(3+) nanocrystals supported by MOF with enhanced near-UV light absorption thereby enhanced luminescence and excellently multifunctional applications

A novel host-guest luminous system with enhanced near-UV light absorption thereby enhanced luminescence are designed based on the synergism of quantum confinement,spatial confinement,and antenna effect,where ultrasmall Y_(2)O_(3):Eu^(3+)nanocrystals are fixed inside MOF(Eu/Y-BTC)as supporting structure.The Eu/Y-BTC not only limits the size and leads to lattice distortion of Y_(2)O_(3):Eu^(3+)nanocrystals and controls the distance between nanocrystals,but also promotes the light absorption and emission.The significantly red-shifted and broadened charge transfer band of Y_(2)O_(3):Eu^(3+)/(Eu/Y-BTC)leads to the excellent applications of Y_(2)O_(3):Eu^(3+)in white light-emitting diodes(LEDs).Our results show that white light with superior color quality(CRI>90)and extremely high luminous efficacy(an LER of 335 lm/W)could be achieved using Y_(2)O_(3):Eu^(3+)/(Eu/Y-BTC)as red phosphor.The Y_(2)O_(3):Eu^(3+)/(Eu/Y-BTC)also improves the photoelectric performance of dye-sensitized solar cells(DSSCs),not only because Y_(2)O_(3):Eu^(3+)/(Eu/Y-BTC)has a large specific surface area and the adsorption amount of the dye is increased,but also because the valence band position of Y_(2)O_(3):Eu^(3+)/(Eu/Y-BTC)is 2.41 eV,which can provide an additional energy level between the TiO2 and dye,promoting electron transfer.For these advantageous features,the multifunctional Y_(2)O_(3):Eu^(3+)/(Eu/Y-BTC)composite product will open new avenues in white LEDs and DSSCs.

Specific targeting of angiogenesis in lung cancer with RGD-conjugated ultrasmall superparamagnetic iron oxide particles using a 4.7T magnetic resonance scanner

Background Angiogenesis is an essential step for tumor development and metastasis.The cell adhesion molecule αvβ3 integrin plays an important role in angiogenesis and is a specific marker of tumor angiogenesis.A novel αvβ3 integrintargeted magnetic resonance （MR） imaging contrast agent utilizing Arg-Gly-Asp （RGD） and ultrasmall superparamagnetic iron oxide particles （USPIO） （referred to as RGD-USPIO） was designed and its uptake by endothelial cells was assessed both in vitro and in vivo to evaluate the angiogenic profile of lung cancer.Methods USPIO were coated with-NH3＋ and conjugated with RGD peptides.Prussian blue staining was performed to evaluate the specific uptake of RGD-USPIO by human umbilical vein endothelial cells （HUVECs）.Targeted uptake and subcellular localization of RGD-USPIO in HUVECs were confirmed by transmission electron microscopy （TEM）.The ability of RGD-USPIO to noninvasively assess αvβ3 integrin positive vessels in lung adenocarcinoma A549 tumor xenografts was evaluated with a 4.7T MR scanner.Immunohistochemistry was used to detect αvβ3 integrin expression and vessel distribution in A549 tumor xenografts.Results HUVECs internalized RGD-USPIO significantly more than plain USPIO.The uptake of RGD-USPIO by HUVECs could be competitively inhibited by addition of free RGD.A significant decrease in T2 signal intensity （SI） was observed at the periphery of A549 tumor xenografts at 30 minutes （P 〈0.05） and 2 hours （P 〈0.01） after RGD-USPIO was injected via the tail vein.Angiogenic blood vessels were mainly distributed in the periphery of tumor xenografts with positive αvβ3 integrin expression.Conclusions RGD-USPIO could specifically label αvβ3 integrin and be taken up by HUVECs.This molecular MR imaging contrast agent can specifically evaluate the angiogenic profile of lung cancer using a 4.7T MR scanner.

Engineering a folic acid-decorated ultrasmall gemcitabine nanocarrier for breast cancer therapy: Dual targeting of tumor cells and tumor-associated macrophages

Combination of passive targeting with active targeting is a promising approach to improve the therapeutic efficacy of nanotherapy.However,most reported polymeric systems have sizes above100 nm,which limits effective extravasation into tumors that are poorly vascularized and have dense stroma.This will,in turn,limit the overall effectiveness of the subsequent uptake by tumor cells via active targeting.In this study,we combined the passive targeting via ultra-small-sized gemcitabine(GEM)-based nanoparticles(NPs)with the active targeting provided by folic acid(FA)conjugation for enhanced dual targeted delivery to tumor cells and tumor-associated macrophages(TAMs).We developed an FAmodified prodrug carrier based on GEM(PGEM)to load doxorubicin(DOX),for co-delivery of GEM and DOX to tumors.The co-delivery system showed small particle size of~10 nm in diameter.The ligand-free and FA-targeted micelles showed comparable drug loading efficiency and a sustained DOX release profile.The FA-conjugated micelles effectively increased DOX uptake in cultured KB cancer cells that express a high level of folate receptor(FR),but no obvious increase was observed in 4T1.2 breast cancer cells that have a low-level expression of FR.Interestingly,in vivo,systemic delivery of FAPGEM/DOX led to enhanced accumulation of the NPs in tumor and drastic reduction of tumor growth in a murine 4T1.2 breast cancer model.Mechanistic study showed that 4T1.2 tumor grown in mice expressed a significantly higher level of FOLR2,which was selectively expressed on TAMs.Thus,targeting of TAM may also contribute to the improved in vivo targeted delivery and therapeutic efficacy.

Microfluidic-enabled ambient-temperature synthesis of ultrasmall bimetallic nanoparticles

The production of bimetallic nanoparticles with ultrasmall sizes is the constant pursuit in chemistry and materials science because of their promising applications in catalysis,electronics and sensing.Here we report ambient-temperature preparation of bimetallic NPs with tunable size and composition using microfluidic-controlled co-reduction of two metal precursors on silicon surface.Instead of free diffusion of metal ions in bulk system,microfluidic flow could well control the local ions concentration,thus leading to homogenous and controllable reduction rate among different nucleation sites.By controlling precursor concentration,flow rate and reaction time,we rationally design a series of bimetallic NPs including Ag-Cu,Ag-Pd,Cu-Pt,Cu-Pd and Pt-Pd NPs with ultrasmall sizes(~3.0 nm),tight size distributions(relative standard deviation(RSD)<21%),clean surface,and homogenous elemental compositions among particles(standard deviation(SD)of weight ratios<3.5%).This approach provides a facile,green and scalable method toward the synthesis of diverse bimetallic NPs with excellent activity.

Structure-design and theoretical-calculation for ultrasmall Co_(3)O_(4) anchored into ionic liquid modified graphene as anode of flexible lithium-ion batteries

Cobalt oxide(Co_(3)O_(4))is currently suitable in energy storage applications because of its high capacity based on the conversion reaction mechanism.However,unmodified Co_(3)O_(4)suffers from distinctly inferior rate capability and poor cycling stability.On the basis of the aforementioned considerations and density functional theory(DFT)simulations,the three-dimensional hierarchical porous structure(HPS)ultrasmall Co_(3)O_(4)anchored into ionic liquid(IL)modified graphene oxide(GO)has been successfully prepared(ultrasmall/Co_(3)O_(4)-GA-IL).The ultrasmall/Co_(3)O_(4)-GA-IL consists of Co_(3)O_(4)co-assembled with IL modified GO to generate the HPS which can facilitate ion transfer channels through reduction of the electron and ion transportation path and transmission impedance.In addition,N-doping graphene can enhance the inherent electrical conductivity of Co_(3)O_(4),which is proved by the DFT calculations.By virtue of the novel superstructure,the ultrasmall/Co_(3)O_(4)-GA-IL electrode demonstrates a high reversible capacity of 1,304 mAh·g^(−1),an enhanced high-rate capability(715 mAh·g^(−1)at 5 C),and a capacity retention of 98.4%even after 500 cycles at 5 C rate,which corresponds to 0.0003%capacity loss per cycle.Pouch cells based on the cathode are further fabricated and demonstrate excellent mechanical and electrochemical properties under bent and folded state,highlighting the practical application of our deliberately designed electrode in wearable electronics.

Single ultrasmall Mn2＋-doped NaNdF4 nanocrystals as multimodal nanoprobes for magnetic resonance and second near-infrared fluorescence imaging

Multimodal imaging probes have attracted wide attention and have potential to diagnose diseases accurately because of the complementary advantages of multiple imaging modalities. However, intractable issues remain with regard to their complicated multi-step fabrication for hybrid nanostructure and interference of different modal imaging. In the present stud we present, for the first time, T1 and T2-weighted magnetic resonance imaging （MRI） of ultrasmaU Mn2＋-doped NaNdF4 nanocrystals （NCs）, which can also be used simultaneously for second near infrared （NIR-U） fluorescence and computed tomography （CT） imaging, thus enabling high-performance multimodal MRI/NIR-II/CT imaging of single NaNdF4：Mn NCs. The NaNdF4：Mn was demonstrated as a nanoprobe for in vitro and in vivo multimodal MRI and NIR-II fluorescence imaging of human mesenchymal stem cells. The results provide a new strategy to simplify the nanostructure and preparation of probes, based on the features of NaNdF4：Mn NCs, which offer highly efficient multimodal MRI/NIR-II/CT imaging.

Ultrasmall Nanoparticle ROS Scavengers Based on Polyhedral Oligomeric Silsesquioxanes

Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structures has remained a grand challenge.In this work,we reported the preparation of ultra-small and precisely structured polyhedral oligomeric silsesquioxanes(POSS)-based polyphenol nanopartides(T8^-,T10^-,and T12^-GAPOSS)by accurately functionalizing the POSS surface with plant polyphenol gallic acid units via thiol-Michael"click"reactions.Those polyphenol nanoparticles exhibited strong free radical scavenging capacity,good biocompatibility and ability to resist cell oxidative damage,which dem on strated great potentials in inhibiting oxidative stress in duced pathologies.

A library of carbon-supported ultrasmall bimetallic nanoparticles

Small-sized bimetallic nanoparticles that possess numerous accessible metal sites and optimal geometric/electronic structures show great promise for advanced synergetic catalysis but remain synthetic challenge so far.Here,an universial synthetic method is developed for building a library of bimetallic nanoparticles on mesoporous sulfur-doped carbon supports,consisting of 24 combinations of 3 noble metals(that is,Pt,Rh,Ir)and 7 other metals,with average particle sizes ranging from 0.7 to 1.4 nm.The synthetic strategy is based on the strong metal-support interaction arising from the metal-sulfur bonding,which suppresses the metal aggregation during the H2-reduction at 700℃ and ensure the formation of small-sized and alloyed bimetallic nanoparticles.The enhanced catalytic properties of the ultrasmall bimetallic nanoparticles are demonstrated in the dehydrogenation of propane at high temperature and oxidative dehydrogenations of N-heterocycles.

Isolated ultrasmall Bi nanosheets for efficient CO_(2)-to-formate electroreduction

Electrochemical reduction of CO_(2) to valuable formate as liquid fuel is a promising way to alleviate the greenhouse effect.The edge active sites in bismuth(Bi)nanosheets play a critical role in the electrochemical reduction of CO_(2) into formate,which enable the operation of CO_(2) reduction with high cathodic energy efficiency,especially under large current densities of≥200 mA/cm^(2).However,the undesirable reconstruction of small Bi nanosheets into large nanosheets leads to the decreasing of edge active sites during electrocatalysis.Here we report stable isolated ultrasmall bismuth nanosheets-synthesized by in-situ electrochemical transformation of ligands covered bismuth vanadate-on silver nanowires as an efficient electrocatalyst for CO_(2)-to-formate reduction.The cooperative electrocatalyst achieves a formate current density of 186 mA/cm^(2) and a cathodic energy efficiency of 75%for formate,which is the only best compared to the literature results.Operand。Raman and morphologic measurements demonstrate that the excellent energy utilization of the electrocatalyst is originated from the rich edge active sites with Bi-O species of the ultrasmall Bi nanosheets.

Ultrasmall Ag nanoclusters anchored on NiCo-layered double hydroxide nanoarray for efficient electrooxidation of 5-hydroxymethylfurfural

Electrochemical oxidation of 5-hydroxymethylfurfural(HMF)has shown promising prospects in producing highly valuable chemicals.Herein,we report the synthesis of ultrasmall Ag nanoclusters anchored on NiColayered double hydroxide(NiCo-LDH)nanosheet arrays(Agn@NiCo-LDH)via a facile electrodeposition strategy.The prepared Agn@NiCo-LDH nanosheet arrays exhibit excellent electrocatalytic HMF oxidation performance with a current density of 10 mA cm^(−2) at 1.29 VRHE and the Faraday efficiency of nearly 100%for 2,5-furandicarboxylic acid production.This study offers an effective approach to rationally design nanoclusters to achieve high catalytic activity for sustainable energy conversion and production.

Ultrasmall Lanthanide-doped NaMgF Nanocrystals: Controlled Synthesis and Optical Properties

Orthorhombic-phase NaMgF3, composed of bio-friendly elements of Na, Mg and F, is considered to be an ideal host matrix for preparing trivalent lanthanide(Ln3+)-doped luminescent nanocrystals(NCs) with color-tunable emissions for diverse biological applications. However, the preparation and the survey on optical properties of ultrasmall(< 10 nm) Ln3+-doped NaMgF3 NCs remain nearly untouched to date. In this paper, we report a series of monodisperse Ln3+-doped orthorhombic-phase NaMgF3 NCs with an average size of ~10 nm that was synthesised by using a modified high-temperature co-precipitation method. Utilizing Eu3+ ion as an efficient optical/structural probe, the successful hetero-valence doping of Ln3+ ion into the lattice of NaMgF3 NCs is well-established irrespective of their different valences and radii between the host cation(e.g. Mg2+) and Ln3+ dopant. Benefiting from this, desirable upconversion luminescence(UCL) ranging from ultraviolet(UV) to visible and to near-infrared(NIR) spectral regions can be easily obtained after the doping of typical UCL couples of Yb3+/Er3+, Yb3+/Tm3+ and Yb3+/Ho3+ into the NaMgF3 NCs upon excitation by using a 980-nm diode laser.