Dual functional NaYF₄:Yb³⁺, Er³⁺@NaYF₄:Yb³⁺, Nd³⁺core–shell nanoparticles for cell temperature sensing and imaging

Abstract

Lanthanide-doped up-conversion nanoparticles (UCNPs) provide a remote temperature sensing approach to monitoring biological microenvironments. In this research, the UCNPs of NaYF:Yb, Er@NaYF:Yb, Nd with hexagonal (β)-phase were synthesized and applied in cell temperature sensing as well as imaging after surface modification with meso-2, 3-dimercaptosuccinic acid. In the core-shell UCNPs, Yb ions were introduced as energy transfer media between sensitizers of Nd and activators of Er to improve Eremission and prevent their quenching behavior due to multiple energy levels of Nd. Under the excitations of 808 nm and 980 nm lasers, the NaYF:Yb, Er@NaYF:Yb, Nd nanoparticles exhibited an efficient green band with two emission peaks at 525 nm and 545 nm, respectively, which originated from the transitions of H → I and S → I for Er ions. We demonstrate that an occurrence of good logarithmic linearity exists between the intensity ratio of these two emission peaks and the reciprocal of the inside or outside temperature of NIH-3T3 cells. A better thermal stability is proved through temperature-dependent spectra with a heating-cooling cycle. The obtained viability of NIH-3T3 cells is greater than 90% after incubations of about 12 and 24 (h), and they possess a lower cytotoxicity of UCNPs. This work provides a method for monitoring the cell temperature and its living state from multiple dimensions including temperature response, cell images and visual up-conversion fluorescent color.

Люминесцентные Наноматериалы, Допированные Редкоземельными Ионами, И Перспективы Их Биомедицинского Применения (Обзор)

“…Среди них матрицы NaYF 4 и NaGdF 4 хорошо зарекомендовали себя как наиболее эффективные материалы для реализации ап-конверсионного механизма передачи энергии. Таким образом, эти материалы широко используются для визуализации in vitro и in vivo [18,[22][23]175,185,186]. Благодаря высокой эффективности ап-конверсии эти нано-И.Н.…”

“…Несмотря на то, что этот метод синтеза позволяет получать высококачественные наночастицы, следует иметь в виду, что он требует дорогостоящих токсичных прекурсоров и приводит к образованию вредных побочных продуктов (например, плавиковой кислоты HF), что ограничивает широкомасштабное использование этой технологии. Yb/Er@NaGdF 4 : Yb, NaGdF 4 : Nd@NaGdF 4 и KGdF 4 : Yb/Tm@KGdF 4[112][113][114][115][116][117].…”

Two-Dimensional and Three-Dimensional Single Particle Tracking of Upconverting Nanoparticles in Living Cells

“…Thermal mapping requires fluorescent nanoprobes with good biocompatibility and high thermal sensitivity to obtain submicron spatial resolution and subdegree thermal resolution. Shi et al [100] treated NIH-3T3 cells with NaYF 4 : Yb 3+ , Er 3+ @NaYF 4 : Yb 3+ , Nd 3+ core–shell nanoparticles to measure the intracellular temperature (Figure 5).…”

“…Thermal images of NIH-3T3 cells treated with external heating [100]. Adapted from [100] with permission from IOPScience. Copyright 2018 IOPScience.…”

Rare Earth Hydroxide as a Precursor for Controlled Fabrication of Uniform β-NaYF4 Nanoparticles: A Novel, Low Cost, and Facile Method

“…In recent years, Lanthanide (Ln 3+ )-doped upconversion nanoparticles (UCNPs) that convert low energy photons into high energy photons through a two- or multi-photon absorption mechanism have extensively attracted researchers’ attention due to their potential applications in a variety of fields, such as bioimaging [1,2,3,4,5,6,7,8], biosensing [9,10], drug delivery [11,12], and cancer therapy [13,14,15,16]. Compared with traditional fluorescent probes, such as organic fluorescent dyes and semiconductor quantum dots, UCNPs possess some unique advantages, including weak background fluorescence, large anti-Stokes shift, high photochemical stability, narrow emission bandwidth, long luminescent lifetime, high penetration depth, and low toxicity, among others [17,18,19,20,21,22,23,24]. Among reported UCNPs, hexagonal phase (β-) sodium yttrium fluoride has been shown to be one of most efficient host materials owing to its low photon cutoff energy (~350 cm −1 ) and high chemical stability, which are able to effectively reduce non-radiative energy losses at the intermediate states of lanthanide ions [25].…”