Interaction of LiYF₄:Yb³⁺/Er³⁺/Ho³⁺/Tm³⁺@LiYF₄:Yb³⁺ upconversion nanoparticles, molecularly imprinted polymers, and templates

Abstract

In this work, LiYF4:Yb0.253+/Er0.013+/Tm0.013+/Ho0.013+@LiYF4:Yb0.23+ upconverting nanoparticles (UCNP) were used as luminescent materials for the preparation of molecular imprinting polymer nanocomposites.

Embedded Upconversion Nanoparticles in Magnetic Molecularly Imprinted Polymers for Photodynamic Therapy of Hepatocellular Carcinoma

“…In Figure 1 c, high-resolution transmission electron microscopy (HRTEM) images show the well-resolved d-spacings of LiYF 4 :Yb 0.25 3+ /Ho 0.01 3+ @ LiYF 4 :Yb 0.20 3+ core/shell nanoparticles that match closely the distance between the (202) planes in lithium yttrium tetrafluoride (LiYF 4 ) with a single-crystalline structure. The selected area electron diffraction patterns in Figure 1 d consist of many spots that are indexed to the corresponding (hkl) planes, according to the Joint Committee on Powder Diffraction standards (JCPDs) #17-0874, indicating that the UCNPs have a single-crystal tetragonal phase structure [ 16 ].…”

“…The synthesis of the core/shell LiYF 4 :Yb 3+ 0.25 /Ho 3+ 0.01 @LiYF 4 :Yb 3+ 0.2 was modified from our previous work [ 16 ]; briefly, (1) Li 2 CO 3 (1.48 mmol), Y 2 O 3 (0.74 mmol), Yb 2 O 3 (0.2 mmol), and Ho 2 O 3 (0.02 mmol) were dissolved in 50% trifluoroacetic acid 10 mL at 90 °C in a three-necked flask for 30 min. (2) This solution was evaporated to dryness under an argon gas purge, and then equal volumes of oleic acid and 1-octadecene 15 mL were added, and heated to 120 °C at 2 °C/min in 30 min.…”

“…MIPs combined with silica-coated UCNPs have been synthesized for the detection of ochratoxin A in corn, rice, and feed [ 15 ]. Our previous work showed that the in situ polymerization of MIP nanocomposites with UCNPs could be used for the recognition of cysteine, albumin, and hemoglobin [ 16 ]. Epitope imprinting has recently been used for larger targets, especially proteins and cells; a thorough review, with a focus on applications of the imprinted polymers in imaging, drug delivery, diagnostics, and tissue engineering, has been published by Piletsky et al [ 17 ].…”

Upconversion Nanoparticles Encapsulated with Molecularly Imprinted Amphiphilic Copolymer as a Fluorescent Probe for Specific Biorecognition

“…The UCNPs@NIP was similarly treated for comparison. The mass balance equation was used to calculate the adsorption capacity (Q) [25,26]…”

“…In contrast, the adsorption capacity of the UCNPs@NIP for Hb was much smaller than that of Alb. In general, the efficiency of imprinting depended strongly on factors such as the strength of the interactions between the template and the polymeric matrix [26], or the shape of the template. Generally, the hydrophobic residues of most proteins are sequestered in the core of the native structure, while the polar residues are present on the surface [35].…”