Self‐Assembly of Upconversion Nanoparticles Based Materials and Their Emerging Applications

Abstract

to photodynamic therapy (PDT), [12][13][14][15][16][17][18] drug delivery, [19][20][21][22][23][24][25][26] molecular detection, [27][28][29][30][31] optogenetics, [32][33][34] etc. On the other side, broader applications of UCNPs are hindered by their low extinction coefficients and quantum efficiency as well as fixed energy levels. [1,[35][36] Moreover, various energy transfer paths among these lanthanide cations often result in deleterious cross-relaxations. Thus, specific multiplexed applications require compositional and structural UCNPs design to be delicate and complex. The creation of such structures is multi-step and timeconsuming. [7,19,[37][38][39][40][41] To resolve these problems, scientists tried to develop UCNPs assemblies containing various UCNPs or UCNPs and other functional counterparts. The resulting composites exhibited unique properties, determined by the dimension and morphology of the individual components and the whole assembly. These properties can also be tuned depending upon the application situation such as dual-modality cell imaging, [26,[42][43] drug delivery, [44][45][46][47][48][49] molecular detection, [50][51] and programmed control therapy. [47][48] In terms of multifunctionality, the UCNPs assembly not only preserve the original upconverting characteristics of UCNPs but also endowed with variable other functional properties with much improved. All these properties help to improve performance and overcome the limitations of UCNPs. The composition, morphology, and assembly manner of individual components can be tuned to obtain the desired properties and adjust them to the specific environment when needed. Combining UCNPs with other materials (quantum dots, [43] metals, [51] polymers, [52][53] DNA, [26,42,54] etc.) minimizes the challenges connected to the UCNPs implementation allowing the resulting materials to exhibit multifunctionalities. These approaches made the composites containing UCNPs very promising for a variety of applications.Recently, a variety of UCNPs assembly synthesis methods was developed, which involve interface, [55][56][57] microemulsion, [52,[58][59] and polymer/DNA [26,46,60] meditated method. Meanwhile, it is not hard for us to observe the appearance of UCNPs assembly in some new applied fields such as DNA detection, [50][51] chemo-photodynamic therapy, [53,60] and programmable therapeutics. [45,[47][48] A grasp of the achievements on the UCNPs assembilies reported over the last years would assist scientists to fully utilize the UCNPs based nanoplatforms for various applications. Thus, Section 2 of this review describes UCNPs properties, and Sections 3 is dedicated to UCNPsIn the past few decades, significant progress of the conventional upconversion nanoparticles (UCNPs) based nanoplatform has been achieved in many fields, and with the development of nanoscience and nanotechnology, more and more complex situations need a UCNPs based nanoplatform having multifunctions for specific multimodal or multiplexed applications. Through self-assembly, different UCN...

Liquid crystal-templated chiral nanomaterials: from chiral plasmonics to circularly polarized luminescence

“…All of these merits render UCNPs particularly useful in diverse emerging applications, such as photoswitching, biosensing, bioimaging, and advanced information displays [279][280][281] . For UCNPs, their low luminescence brightness, low extinction coefficients as well as fixed energy levels remain major challenges for unlocking their full potential 282 . Over the past decade, considerable efforts have been made in the judicious design and synthesis of lanthanide-based UCNPs exhibiting robust photoluminescence properties 283 .…”

Multiplex Chroma Response Wearable Hydrogel Patch: Visual Monitoring of Urea in Body Fluids for Health Prognosis

“…However, most of the currently reported fluorescent hydrogels are excited by short wavelengths and are susceptible to interference from autofluorescence and background fluorescence when detecting biological samples . Recently, the applications of upconversion nanoparticles (UCNPs) in biomedical fields such as biological detection, biological imaging, disease treatment have been rapidly developed. − Compared with traditional fluorescent materials, the UCNPs can be tuned to biological windows, which effectively reduces the absorption of light by tissues, giving UCNPs deeper tissue penetration and good optical stability, a high signal-to-noise ratio (SNR), no background fluorescence interference, and almost no damage to biological tissues . Therefore, it is an effective strategy to utilize the upconversion optical method to design wearable sensors in the detection of human bio-markers.…”

The Formation of NaYF4 : Er3+, Yb3+ Nanocrystals Studied by In Situ X‐ray Scattering: Phase Transition and Size Focusing

“…Where bulk materials are usually superior in terms of quantum efficiency, [9,10,12] colloidal nanocrystals (NCs) are non-scattering and solvent-dispersible, which makes them preferable for various applications [8] and processing methods. [13,14] NaREF 4 NCs of the cubic α-phase were first reported in 2004. [15] A synthesis procedure for NCs of the hexagonal βphase followed in 2006.…”