Exploring the use of upconversion nanoparticles in chemical and biological sensors: from surface modifications to point-of-care devices

Abstract

Upconversion nanoparticles (UCNPs) have emerged as promising luminescent nanomaterials due to their unique features that allow the overcoming of several problems associated with conventional fluorescent probes. Although the UCNPs have...

Multifunctional Platform Based on a Copper(I) Complex and NaYF4:Tm3+,Yb3+ Upconverting Nanoparticles Immobilized into a Polystyrene Matrix: Downshifting and Upconversion Oxygen Sensing

“…These hybrid samples showed considerable sensitivity to O 2 by emission quenching. By exciting the UCNP:1@PS- (25,50) samples with a 980 nm laser as a function of increasing oxygen concentration, it is possible to notice a decrease in the intensity of the broadened emission in the green (500−625 nm) of the copper complex (Figure 7). By fitting the Stern−Volmer plots, K sv = 1.22 and 3.66 were found for the UCNP:1@PS-25 and UCNP:1@PS-50 materials, respectively.…”

“…21 Besides the organometallic complexes, another class of versatile luminescent materials is that of the crystalline nanoparticles, which have been widely explored individually or in combination with other species for the construction of multifunctional platforms. 25 Among these, upconversion nanoparticles (UCNPs) doped with trivalent lanthanides (Ln 3+ ) have gained a lot of attention in recent years due to their unique properties such as anti-Stokes emission and excitation wavelengths within the biological window. UCNPs are nanoparticles that can convert low-energy excitation into higher-energy emission photons (through multiphoton absorption processes).…”

Synthesis of near-infrared-responsive hexagonal-phase upconversion nanoparticles with controllable shape and luminescence efficiency for theranostic applications

“…[20][21][22] FRET is a non-radiative process characterized by energy transfer between the excited state of donors and the ground state of acceptors through long-range dipoledipole couplings. 23,24 For the FRET process to occur effectively, first, the absorption spectrum of the acceptor and the emission spectrum of the donor should overlap, and second, the distance between the acceptor and the donor should be less than a few nanometers. 25 Under these conditions, an energy transfer occurs between the donor (UCNs) and the acceptor (PS), thereby generating ROS for FRET-based PDT.…”

A facile visualized solid-phase detection of virus-specific nucleic acid sequences through an upconversion activated linear luminescence recovery process

“…5 Typically, they can be absorbed in the near-infrared (NIR) region and emit higher energy photons in the ultraviolet (UV) and/or visible (vis) regions. 6,7 Compared with traditional fluorescent probes (such as organic dyes, metal complexes or inorganic quantum dots), UCNPs are ideal energy donors in biosensors, on account of the merits such as non-autofluorescence, excellent chemical stability, the large penetration depth of light, long lifetime, and less damage to samples. [8][9][10][11][12][13][14][15] Gold nanoparticles (AuNPs) with high specific surface area have strong light absorption capacity, and their extinction coefficients are usually two to three orders of magnitude higher than that of quantum dots and organic dyes.…”