Lanthanide ions doped in vanadium oxide for sensitive optical glucose detection

Marlan O. Scully,Carmen L. Gomes,Philip R. Hemmer,Fahad Alghannam,Robert Brick,Alexei V. Sokolov,Linkun Jiang,Ansam J. Talib,Masfer Alkahtani

doi:10.1364/ome.8.003277

Abstract

Blood glucose monitoring is essential to avoid the unwanted consequences of glucose level fluctuations. Optical monitors are of special interest because they can be non-invasive. Among optical glucose sensors, fluorescent upconversion nanoparticles (UCNPs) have the advantage of good photostability, low toxicity, and exceptional autofluorescence suppression. However, to sense glucose, UCNPs normally need surface functionalization, and this can be easily affected by other factors in biological systems, and may also affect their ability for real-time sensing of both increasing and decreasing glucose levels. Here, we report YVO4 : Yb3+, Er3+@Nd3+ core/shell UCNPs with Nd and Yb shell and GdVO4 : Yb3+, Er3+@Nd3+ core/shell UCNPs with Nd and Yb shell that show sensitive, reversible, and selective optical glucose detection without the need for any surface functionalization or modifications.

Highlights

Diabetes endangers the health of millions of people all over the world
A thin layer of GdVO4 : Er3+, Yb3+@Nd3+ core/shell upconversion nanoparticles (UCNPs) was uniformly distributed on a quartz slide
For GdVO4 : Er3+, Yb3+@Nd3+ UCNPs, a droplet was placed on a carbon grid for transmission electron microscopy (TEM) imaging

Summary

Introduction

Diabetes (hyperglycemia) endangers the health of millions of people all over the world. One class of optical sensors is based on the change in emission intensity and/or fluorescence-lifetime of fluorescent particles as a function of glucose concentrations [12] These include organic dyes, quantum dots (QDs), and noble metal nanoparticles (NPs) functionalized with boronic acid, which provide sensitive and reversible glucose level monitoring systems [13,14,15,16,17]. Most of these optical sensors are limited by photostability, especially for dyes, and toxicity, especially for QDs. noble metal nanoparticles are sensitive to other factors in the local environment, besides glucose levels, for example their emission can be affected by pH levels [18,19,20, 31]. In addition to being naturally glucose-sensitive, vanadate crystals like YVO4 and GdVO4 have shown high upconversion efficiency and good photostability in water, as reported in [35, 43,44,45]

Methods

Core synthesis

Shell mixture preparation

Results and discussion

Conclusions