Silica-Coated S^2–-Enriched Manganese-Doped ZnS Quantum Dots as a Photoluminescence Probe for Imaging Intracellular Zn²⁺ Ions

Abstract

Detection of intracellular Zn(2+) has gained great attention because of its biological significances. Here we show the fabrication of silica-coated S(2-)-enriched Mn-doped ZnS quantum dots (SiO(2)-S-Mn-ZnS QDs) by enriching S(2-) with a silica shell on the surface of Mn-doped ZnS QDs via a sol-gel process for imaging intracellular Zn(2+) ions. The developed probe gave a good linearity for the calibration plot (the recovered PL intensity of the SiO(2)-S-Mn-ZnS QDs against the concentration of Zn(2+) from 0.3 to 15.0 μM), excellent reproducibility (1.2% relative standard deviation for 11 replicate measurements of Zn(2+) at 3 μM), and low detection limit (3s; 80 nM Zn(2+)). The SiO(2)-S-Mn-ZnS QDs showed negligible cytotoxicity, good sensitivity, and selectivity for Zn(2+) in a photoluminescence turn-on mode, being a promising probe for photoluminescence imaging of intracellular Zn(2+).

Fluorescent nanoprobes for sensing and imaging of metal ions: Recent advances and future perspectives

“…Doped QDs can not only potentially retain almost all of the advantages of q-dots, but can also avoid the self-quenching problem due to their substantial ensemble Stokes shift [227]. To date, a variety of transition-metal and lanthanide-metal ions, including Mn 2+ , Cu 2+ , Co 2+ , Ni 2+ , Ag + , Pb 2+ , Cr 3+ , Eu 3+ , Sm 3+ , and Er 3+ , have been doped into QDs, making doped QDs attractive for diverse applications in metal ion sensing and imaging [177,178,227,237]. …”

“…In particular, the Yan [237] group developed QD-based photoluminescence imaging for intracellular Zn 2+ (Figure 14A). Silica-coated S 2− -enriched Mn-doped ZnS QDs (SiO 2 -S-Mn-ZnS QDs) were fabricated by enriching S 2− with a silica shell on the surface of Mn-doped ZnS QDs via a sol-gel process for imaging intracellular Zn 2+ .…”

“…Confocal fluorescent images of HeLa cells before (left) and after (right) addition of Cu 2+ (20 μM). (A and B: Adapted with permission from [237]. Copyright 2011 American Chemical Society, C and D: Adapted from [238] with permission of The Royal Society of Chemistry)…”

L-cysteine capped ZnS:Mn quantum dots for room-temperature detection of dopamine with high sensitivity and selectivity

“…Its optical sensing is based on the interaction of a fraction of atoms/molecules on a treated surface, which strongly affects the recombination of electrons and holes within the particles, and in turn the emission response . Following this process, many analytes have been successfully detected, such as ions (Hg 2 þ , Co 2 þ , Zn 2 þ and Zr 4 þ ) (Bian et al, 2014;Gong et al, 2014a;Ren et al, 2011;Tan et al, 2012); proteins/enzymes, clenbuterol and glucose in biological fluids (Gong et al, 2014b;Wu et al, 2013;Wu et al, 2010;Zhang et al, 2013); organophosphorus pesticides (Ban et al, 2014); phenols in different media (Liu et al, 2010;Wei et al, 2015;Zhang et al, 2015b); and cathecol, domoic acid, rutin, urea, idarubicin and DNA (Bi et al, 2014;Dan et al, 2013;Ertas et al, 2015;Miao et al, 2014;Wang et al, 2013). Recently, Bian and co-workers, employing N-acetyl-L-cysteine and L-cysteine capped ZnS:Mn QDs as probes, showed the luminescent detection of L-ascorbic acid (AA) with high selectivity and long luminescence lifetime (Bian et al, 2013).…”

Chemical bath deposited MgxZn1−xS(O) thin films and their photoluminescence properties

“…Mg doping in-to the ZnS lattice has an effect on the intensity of the emission resulting from defect states [18]. These can be used in biological application, such as for detecting the phosphorescence of arginine and methylated arginine in urine at room temperature [19] as well as detect intracellular Zn 2+ that can accumulate in patients with Alzheimer's disease, diabetes, and cancer [20]. A strong UV emission at around 300 nm was obtained from a zincblende Mg x Zn 1x S(O) single crystal with an Mg composition of up to x = 0.4 [21].…”