Plasmon-induced double-field-enhanced upconversion nanoprobes with near-infrared resonances for high-sensitivity optical bio-imaging

Abstract

High-sensitivity optical imaging can be achieved through improving upconversion photoluminescence (UCPL) efficiency of localized surface plasmon resonance (LSPR)-enhanced excitation and emission. Herein, we report a type of UCPL nanoprobe, Au nanospheres assemblage@Gd 2 O 3 :Yb 3+ /Ln 3+ (Ln=Er, Ho, Tm), which exhibits emission enhancements from 46-to 96-fold as compared with its Au-free counterparts. The aggregation and interaction among Au nanospheres embedded inside the nanoprobe brings about three characteristic LSPR peaks in visible and near-infrared regions according to simulated and experimental absorption spectra, resulting in both excitation and emission fields simultaneously intensified all through the entire nanoprobe. We addressed a characteristic wavelength dependence on emission amplifications, which could be elucidated by a LSPR-enhanced UCPL mechanism and relevant rate equations that we addressed. The nanoprobe was verified to have a superior capability for optical bio-imaging with a negligible toxicity in vitro and in vivo. This study realizes a synchronous double-field-enhanced upconversion of optical nanoprobe in situ, and may gain an insight into its mechanism underlying for LSPR-induced UCPL enhancement.

Enhancement of Upconversion Luminescence through Three-Dimensional Design of Plasma Ti3O5-Coupled Structural Domain-Limiting Effects

“…They exhibit a broad range of luminescence radiative rates and intensity enhancements. 14,15 The intensity of LSPR is strictly dependent on the resonance absorption of the plasma source. In recent years, the discovery of LSPR in defective semi-conductors has been an exciting research achievement.…”

Double local electromagnetic fields collaboratively enhanced triplet–triplet annihilation upconversion for efficient photocatalysis

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Noninvasive Detection of Bladder Cancer Markers Based on Gold Nanomushrooms and Sandwich Immunoassays

“…The interactions between incident light and metal nanostructures achieve significant resonance and near-field enhancement characteristics. The near-field enhancement enjoys a reputation in biomedical applications, such as SERS, photothermal therapy, biological imaging, and biological sensing. , Among these applications, LSPR refractive index sensing is a common sensing strategy, which is widely used in sensing biomolecules, such as cell culture monitoring, proteins, , cell capture, DNA, microRNA, bacterial, protein–DNA interactions, and DNA/RNA hybridization . It provides high sensitivity, low cost, rapid, and label free approach based on the spectral shift with the variation of environmental refractive index around the nanostructure surface, making it a superior candidate for biosensing.…”