Ag doped HgS Quantum Dots: a pH-tunable Near-infrared-Ⅱ Fluorescent Nanoprobe

doi:10.15541/jim20190031

Abstract

Abstract:

Design and preparation of near-infrared (NIR) especially NIR-Ⅱ (1000-1700 nm) fluorescence probe with favorable biocompatibility and high quantum yield have become the focus of noninvasive fluorescent imaging in recent years. In this study, Ag doped HgS QDs (HgAgS QDs) were prepared at different synthetic pH. With the increase of pH, the fluorescence emission peak of the HgAgS QDs red-shifted and then blue-shifted, reaching a maximum emission wavelength of 1110 nm (QY=8.12%) at pH 6.0. Atomic absorption spectroscopy showed that the doping amount of Ag (Ag/Hg ratio) changed regularly in HgAgS QDs prepared at different pH solutions, which was consistent with change of fluorescence emission position. It was proved that pH could tune the position of fluorescence emission peak by adjusting the doping amount of Ag. Moreover, the quantum yield (QY) of HgAgS QDs increased firstly and then decreased, presenting an optimum of 13.23% (λ_em=1100 nm) at pH 7.0. Cell viability tests demonstrated that the doping amount of Ag showed no significant effect on cytotoxicity. And all HgAgS QDs had no cytotoxicity at the concentration range of 1-50 μg/L, thus can be used as a pH-tunable NIR-Ⅱ fluorescent probe. These findings provide a promising application in the NIR fluorescent imaging and an interesting insight into the design and preparation of the NIR-Ⅱ fluorescence nanoprobe.

Key words: NIR-Ⅱ fluorescence, HgAgS quantum dots, pH-tunable, hot injection

CLC Number:

TQ174

WANG Jun-Cheng, YANG Fei-Fei, GAO Guan-Bin, SUN Tao-Lei. Ag doped HgS Quantum Dots: a pH-tunable Near-infrared-Ⅱ Fluorescent Nanoprobe[J]. Journal of Inorganic Materials, 2019, 34(11): 1156-1160.

Figures/Tables 9

Fig. 1 XRD pattern (a), TEM image (b), HR-TEM image (c), and size distribution (d) of HgAgS QDs

Fig. 2 High-angle annular dark field (HAADF), STEM image (a) and EDS (b) of HgAgS QDs; Mixed elements mapping of HgAgS QDs (c) with corresponding single element Ag(blue) (d), Hg(red) (e) and S(yellow) (f) elements distribution

Fig. 3 FT-IR spectra of captopril and HgAgS QDs

Fig. 4 Fluorescence (a) and Ag/Hg value (b) of HgAgS QDs with different synthetic pH (Ex=400 nm) (colourful edition is available on website)

Fig. 5 Cell viability of HgAgS QDs prepared at pH 6.0 on INS-1 cells for 24 and 48 h (a), and cell viability of HgAgS QDs prepared at pH=3.0, 5.0, 6.0 and 11.0 on PC12 cells (b). Concentrations of HgAgS QDs were 0, 1, 10, 20 and 50 μg/L

Fig. 6 Fig. S1 HR-TEM images of HgAgS QDs synthesized at pH 5 (a), 9 (b) and 11 (c)

Fig. 7 Fig. S2 Hydrate particle size of HgAgS QDs

Fig. 8 Fig. S3 Survey spectra (a), Ag3d (b), Hg4f (c) and S2p (d) spectra of HgS QDs (black curves) and HgAgS QDs (red curves)

Fig. 9 Fig. S4 QYs of HgAgS QDs, Ex = 400 nm

References 22

[1]	LIU SHI-YU, XIONG HAO, LI RONG-RONG , et al. Activity- based near-infrared fluorogenic probe enables in vitro and in vivo profiling of neutrophil elastase. Analytical Chemistry, 2019,91(6):3877-3884.
[2]	NING JING, LIU TAO, DONG PEI-PEI , et al. Molecular design strategy to construct the near-infrared fluorescent probe for selectively sensing human cytochrome P450 2J2. Journal of the American Chemical Society, 2019,141(2):1126-1134.
[3]	LIU TZU-MING, CONDE JOAO, LIPINSKI TOMASZ , et al. Revisiting the classification of NIR-absorbing/emitting nanomaterials for in vivo bioapplications. NPG Asia Materials, 2016,8:25.
[4]	BHATTARAI DEVAL-PRASAD, TIWARI ARJUN-PRASAD, MAHARJAN BIKENDRA , et al. Sacrificial template-based synthetic approach of polypyrrole hollow fibers for photothermal therapy. Journal of Colloid and Interface Science, 2019,534:447-458.
[5]	TIAN YE, RAN RAN, JIAO YUN-FENG , et al. Redox stimuli- responsive hollow mesoporous silica nanocarriers for targeted drug delivery in cancer therapy. Nanoscale Horizons, 2016,1(6):480-487.
[6]	LIU YANG, SONG NAN, LI ZHEN-SHENG , et al. Near-infrared nanoparticles based on aza-BDP for photodynamic and photothermal therapy. Dyes and Pigments, 2019,160:71-78.
[7]	WANG XUAN, LI ZHONG-LIANG, NAN NAN , et al. A simple system of swept source optical coherence tomography for a large imaging depth range. Optics Communications, 2019,431:51-57.
[8]	HANKIEWICZ J H, STOLL J A, STROUD J , et al. Nano-sized ferrite particles for magnetic resonance imaging thermometry. Journal of Magnetism and Magnetic Materials, 2019,469:550-557.
[9]	LAN XIANG, WANG QIANG-BIN . Optically active AuNR@Ag core-shell nanoparticles and hierarchical assembly via DNA-mediated surface chemistry. ACS Applied Materials & Interfaces, 2016,8(50):34598-34602.
[10]	KONG YI-FEI, CHEN JUN, FANG HONG-WEI , et al. Highly fluorescent ribonuclease-A-encapsulated lead sulfide quantum dots for ultrasensitive fluorescence in vivo imaging in the second near- infrared window. Chemistry of Materials, 2016,28(9):3041-3050.
[11]	LIN SHU, FENG YU, WEN XIAO-MING , et al. Theoretical and experimental investigation of the electronic structure and quantum confinement of wet-chemistry synthesized Ag₂S nanocrystals. Journal of Physical Chemistry C, 2014,119(1):867-872.
[12]	YANG JING, HU YAO-PING, TAN JIANG-WEI , et al. Ultra- bright near-infrared-emitting HgS/ZnS core/shell nanocrystals for in vitro and in vivo imaging. Journal of Materials Chemistry B, 2015,3(34):6928-6938.
[13]	ZHANG MING-XI, YUE JING-YING, CUI RAN , et al. Bright quantum dots emitting at similar to 1,600 nm in the NIR-IIb window for deep tissue fluorescence imaging. Proceedings of the National Academy of Sciences of the United States of America, 2018,115(26):6590-6595.
[14]	XIONG HU, ZHOU KE-JIN, YAN YUN-FENG , et al. Tumor- activated water-soluble photosensitizers for near-infrared photodynamic cancer therapy. ACS Applied Materials & Interfaces, 2018,10(19):16335-16343.
[15]	YANG ZHEN, TIAN RUI, WU JIN-JUN , et al. Impact of semiconducting perylene diimide nanoparticle size on lymph node mapping and cancer imaging. ACS Nano, 2017,11(4):4247-4255.
[16]	BRAUN MARKUS, BURDA CLEMENS, EI-SAYED MOSTAFA-A . Variation of the thickness and number of wells in the CdS/ HgS/CdS quantum dot quantum well system. Journal of Physical Chemistry A, 2001,105(22):5548-5551.
[17]	ZHANG WEN-HAO, YANG JING, YU JUN-SHENG . Synthesis of stable near-infrared emitting HgTe/CdS core/shell nanocrystals using dihydrolipoic acid as stabilizer. Journal of Materials Chemistry, 2012,22(13):6383-6388.
[18]	SUN TING-TING, DOU JIN-HU, LIU SHI , et al. Second near-infrared conjugated polymer nanoparticles for photoacoustic imaging and photothermal therapy. ACS Applied Materials & Interfaces, 2018,10(9):7919-7926.
[19]	QIN HAI-YAN, NIU YUAN, MENG REN-YANG , et al. Single- dot spectroscopy of zinc-blende CdSe/CdS core/shell nano-crystals: nonblinking and correlation with ensemble measurements. Journal of the American Chemical Society, 2014,136(1):179-187.
[20]	GAO GUAN-BIN, ZHANG MING-XI, GONG DE-JUN , et al. The size-effect of gold nanoparticles and nanoclusters in the inhibition of amyloid-beta fibrillation. Nanoscale, 2017,9(12):4107-4113.
[21]	SHEN GUO-HUA, GUYOT-SIONNEST PHILIPPE . HgS and HgS/CdS colloidal quantum dots with infrared intraband transitions and emergence of a surface plasmon. Journal of Physical Chemistry C, 2016,120(21):11744-11753.
[22]	YANG FEI-FEI, GAO GUAN-BIN, WANG JUN-CHENG , et al. Chiral β-HgS quantum dots: aqueous synthesis, optical properties and cytocompatibility. Journal of Colloid and Interface Science, 2019,537:422-430.