Dye-conjugated upconversion nanoparticles for ratiometric imaging of intracellular pH values

Abstract

An xylenol orange-functionalized upconversion nanoprobe has been developed, which can be used for ratiometric upconversion luminescence bioimaging of intracellular pH changes.

Upconversion Luminescence Sensitized pH-Nanoprobes

“…The NIR light falls within the biological transparency window (700–1300 nm) and its deep-penetration and low auto-fluorescence give low photostability in comparison to UV and visible light. Most of the optical pH-sensors are investigated to perform within this window [ 30 , 31 , 32 , 33 , 34 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ]. A list of the UC materials speculating pH-sensing is given in Table 2 .…”

Effect of tetragonal to cubic phase transition on the upconversion luminescence properties of A/B site erbium-doped perovskite BaTiO3

“…Upconversion (UC) is a useful photophysical phenomenon and has been applied in various elds, such as the solar cell industry, 1-3 biological imaging 4,5 or pH sensing, [6][7][8] and temperature sensing. [9][10][11] The range of spectral emissions of upconversion luminescence (UCL) from upconversion materials (e.g.…”

Multicolor Upconversion Nanoprobes Based on a Dual Luminescence Resonance Energy Transfer Assay for Simultaneous Detection and Bioimaging of [Ca2+]i and pHi in Living Cells

“…[1] Meanwhile, intracellular concentration of calcium ion ([Ca 2 + ] i )i s the key signal for cell division, differentiation, and maturation, and it is relatedt ophysiological responses in obesitya sw ell as immune and pathological responses in Alzheimer's diseases. [1] Meanwhile, intracellular concentration of calcium ion ([Ca 2 + ] i )i s the key signal for cell division, differentiation, and maturation, and it is relatedt ophysiological responses in obesitya sw ell as immune and pathological responses in Alzheimer's diseases.…”

“…Intracellular pH (pH i )c ould affect enzymatic activity,i on transport, cellularp roliferation, and apoptosis;t herefore, its abnormal level couldr esult in cell dysfunction and accompanying diseases sucha ss troke, Alzheimer's disease, and even cancer. [1] Meanwhile, intracellular concentration of calcium ion ([Ca 2 + ] i )i s the key signal for cell division, differentiation, and maturation, and it is relatedt ophysiological responses in obesitya sw ell as immune and pathological responses in Alzheimer's diseases. [2] [Ca 2 + ] i homeostasisc ould be changed by pH i through several Ca 2 + -regulatory mechanisms, [3] and links change in pH i to cellular functions;t hus, [Ca 2 + ] i is an important comediator of pHinduced effects in cells.…”