Molecular interactions of re-released proteins in electrophoresis of human erythrocytes

Recently, we found that hemoglobin (Hb) could be re-released from live erythrocytes during electrophoresis release test (ERT). The re-released Hb displays single-band and multiple-band re-release types, but its exact mechanism is not well understood. In this article, the protein components of the single-band re-released Hb were examined. First, the re-released band of erythrocytes and the corresponding band of hemolysate, which was used as control, were cut out from starch-agarose mixed gel. Next, proteins were recovered from the starch-agarose mixed gel by freeze-thaw method. After condensing in a vacuum freeze drier, the samples were loaded onto a 5-12% SDS-PAGE. After electrophoresis, three protein bands (16, 28.9, and 29.3 kDa) emerged from the erythrocytes re-released Hb single-band (R-R), but only one band (29.3 kDa) emerged from the corresponding hemolysate control band (H-R). Finally, these bands were analyzed by MALDI-TOF MS. The results showed that these proteins were beta-globin (16 kDa), carbonic anhydrase 1 (CA1, 28.9 kDa), and carbonic anhydrase 2 (CA2, 29.3 kDa). Because CA2 exists in both erythrocytes re-released band and hemolysate control band, we conclude that the single-band re-released Hb is mainly composed of HbA and CA1. Studying the possible interaction between HbA and CA1 will help us further understand the in vivo function of Hb.     

Nitrile‐functionalized Hg(II)‐ and Ag(I)‐N‐heterocyclic carbene complexes: synthesis,crystal structures,nuclease and DNA binding activities

Various nitrile‐functionalized benzimidazol‐2‐ylidene carbene complexes of Hg(II) and Ag(I) were synthesized by the interaction of 1‐benzyl/1‐butyl‐3‐(cyano‐benzyl)‐3 H‐benzimidazol‐1‐ium mono/dihexafluorophosphate with Hg(OAc)₂/Ag₂O in acetonitrile. Two of the benzimidazolium salts were structurally characterized by single crystal X‐ray diffraction technique. Structures of reported compounds were characterized by ¹ H, ¹³C NMR, FT‐IR, UV–visible spectroscopic techniques, and molar conductivity and elemental analyses. For bis‐benzimidazolium salt, dinuclear Hg(II)– and Ag(I)–carbene complexes were obtained. Nuclease activity and binding interactions of the synthesized benzimidazolium salts and their Ag(I)–carbene complexes with DNA were studied using agarose gel electrophoresis and, absorption spectroscopy and viscosity measurements, respectively. Ag(I)–carbene complexes showed higher DNA binding activity compared to their respective benzimidazolium salts. However, a benzimidazolium salt and two of the Ag(I) complexes showed remarkably higher nuclease activity both, in the presence and absence of an oxidizing agent. Copyright © 2012 John Wiley & Sons, Ltd.     

硫杂蒽酮镍（II）配合物与DNA的作用研究

合成了O-（硫杂蒽酮-[2]-基）-氧乙酸镍（II）配合物。通过元素分析,IR, DTA-TG谱对其结构进行了表征。研究表明：配体羧羰基脱质子后与镍离子配位,配合物中含有一定量的配位水。同时以紫外可见光谱、荧光光谱、园二色谱,电化学方法和凝胶电泳方法研究了该配合物与DNA的作用。结果表明,该配合物能在生理条件下比配体和金属离子更有效地切割质粒DNA,自由基捕捉剂的加入不影响配合物的切割活性。该配合物使DNA溶液的紫外吸收强度和园二色吸收强度降低,DNA的存在可使该配合物的氧化还原活性降低。与溴化乙锭和DNA的竞争反应说明,该配合物主要以嵌入方式与DNA结合。     

Novel moving reaction boundary-induced stacking and separation of human hemoglobins in slab polyacrylamide gel electrophoresis

We developed a novel polyacrylamide gel electrophoresis (PAGE) method to stack and separate human hemoglobins (Hbs) based on the concept of moving reaction boundary (MRB). This differs from the classic isotachophoresis (ITP)-based stacking PAGE in the aspect of buffer composition, including the electrode buffer (pH 8.62 Tris–Gly), sample buffer (pH 6.78 Tris–Gly), and separation buffer (pH 8.52 Tris–Gly). In the MRB-PAGE system, a transient MRB was formed between alkaline electrode buffer and acidic sample buffer, being designed to move toward the anode. Hbs carried partial positive charges in the sample buffer due to its pH below pI values of Hbs, resulting in electromigrating to the cathode. Hbs would carry negative charges quickly when migrated into the alkaline electrode buffer and be transported to the anode until meeting the sample buffer again. Thus, Hbs were stacked within a MRB until the transient MRB reached the separation buffer and then separated by zone electrophoresis with molecular sieve effect of the gel. The experimental results demonstrated that there were three clear and sharp protein zones of Hbs (HbA_1c, HbA₀, and HbA₂) in MRB-PAGE, in contrast to only one protein zone (HbA₀) in ITP-PAGE for large-volume loading (≥15 μl), indicating high stacking efficiency, separation resolution, and good sensitivity of MRB-PAGE. In addition, MRB-PAGE was performed in a conventional slab PAGE device, requiring no special device. Thus, it could be widely used in separation and analysis of diluted protein in a standard laboratory.

Measurement and prediction of solubilities and diffusion coefficients of carbon dioxide in starch–water mixtures at elevated pressures

The solubility and diffusion coefficient of carbon dioxide in intermediate‐moisture starch–water mixtures were determined both experimentally and theoretically at elevated pressures up to 16 MPa at 50 °C. A high‐pressure decay sorption system was assembled to measure the equilibrium CO₂ mass uptake by the starch–water system. The experimentally measured solubilities accounted for the estimated swollen volume by Sanchez–Lacombe equation of state (S‐L EOS) were found to increase almost linearly with pressure, yielding 4.0 g CO₂/g starch–water system at 16 MPa. Moreover, CO₂ solubilities above 5 MPa displayed a solubility increase, which was not contributed by the water fraction in the starch–water mixture. The solubilities, however, showed no dependence on the degree of gelatinization (DG) of starch. The diffusion coefficient of CO₂ was found to increase with concentration of dissolved CO₂, which is pressure‐dependent, and decrease with increasing DG in the range of 50–100%. A free‐volume‐based diffusion model proposed by Areerat was employed to predict the CO₂ diffusivity in terms of pressure, temperature, and the concentration of dissolved CO₂. S‐L EOS was once more used to determine the specific free volume of the mixture system. The predicted diffusion coefficients showed to correlate well with the measured values for all starch–water mixtures. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 607–621, 2006     

Physically crosslinked poly(vinyl alcohol)-hydroxyethyl starch blend hydrogel membranes: Synthesis and characterization for biomedical applications

Poly(vinyl alcohol), PVA is a polymer of great importance because of its many appealing characteristics specifically for various pharmaceutical and biomedical applications. Physically crosslinked hydrogel membranes composed of different amounts of hydroxyethyl starch (HES) in (PVA) and ampicillin were prepared by applying freeze–thawing method. This freezing–thawing cycle was repeated for three consecutive cycles. Physicochemical properties of PVA–HES membrane gel such as gel fraction, swelling, morphology, elongation, tensile strength, and protein adsorption were investigated. Introducing HES into freeze–thawed PVA structure affected crystal size distribution of PVA; and hence physicochemical properties and morphological structure have been affected. Increased HES concentration decreased the gel fraction %, maximum strength and break elongation. Indeed it resulted into a significant incrementing of the swelling ability, amount of protein adsorption, broader pore size, and pore distribution of membrane morphological structure. Furthermore, an increase in HES concentration resulted in better and still lower thermal stability compared to virgin PVA and freeze–thawed PVA. The maximum weight loss of PVA–HES hydrogel membranes ranged between 18% and 60% according to HES content, after two days of degradation in phosphate buffer saline (PBS), which indicates they are biodegradable. Thus, PVA–HES hydrogel membranes containing ampicillin could be a novel approach for biomedical application e.g. wound dressing purposes.     

Cryopreservative Effects of the Recombinant Ice-Binding Protein from the Arctic Yeast Leucosporidium sp. on Red Blood Cells

Antifreeze proteins (AFPs) have important functions in many freeze-tolerant organisms. The proteins non-colligatively lower the freezing point and functionally inhibit ice recrystallization in frozen solutions. In our previous studies, we found that the Arctic yeast Leucosporidium sp. produces an AFP (LeIBP), and that the protein could be successfully produced in Pichia expression system. The present study showed that recombinant LeIBP possesses the ability to reduce the damage induced to red blood cells (RBCs) by freeze thawing. In addition to 40?% glycerol, both 0.4 and 0.8?mg/ml LeIBPs significantly reduced freeze?Cthaw-induced hemolysis at either rapid- (45?°C) or slow-warming (22?°C) temperatures. Post-thaw cell counts of the cryopreserved RBCs were dramatically enhanced, in particular, in 0.8?mg/ml LeIBP. Interestingly, the cryopreserved cells in the presence of LeIBP showed preserved cell size distribution. These results indicate that the ability of LeIBP to inhibit ice recrystallization helps the RBCs avoid critically damaging electrolyte concentrations, which are known as solution effects. Considering all these data, LeIBP can be thought of as a key component in improving RBC cryopreservation efficiency.     

Glycated hemoglobin biosensing integration formed on Au nanoparticle-dotted tubular TiO2 nanoarray

Excessive glucose present in the blood of diabetic patients binds with the hemoglobin of red blood cells resulting in the formation of glycated hemoglobin (HbA_1c). Measurement of HbA_1c levels may help in identifying the efficacy of the ongoing treatment and hence provide a better control over the disease. In the present study, we have synthesized a sensitive and stable scaffold, which consists of Au nanoparticles (GNPs)-dotted tubular TiO₂, for the construction of an electrochemical HbA_1c biosensor. 12-phosphotungstic acid has been used as a reducer after depositing well-dispersed GNPs on TiO₂ nanotubes (TiO₂ NTs) and an electron mediator by accelerating the electron transfer between the conductor and protein. The fabricated electrode was characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopic analysis (EIS). Biosensor exhibited low detection limit (0.5 μM), fast response time (3 s) and wide linearity (from 0.5 to 2000 μM). The working electrode was used 100 times over 4 months, when stored at 4 °C. The HbA1c biosensor was then effectively used to measure the % of HbA_1c in the blood of apparently healthy persons and diabetic patients.     

An Electrochemical Impedance Immunosensor Based on Gold Nanoparticle‐Modified Electrodes for the Detection of HbA1c in Human Blood

A label‐free immunosensor for the detection of HbA1c was developed based on gold nanoparticle (AuNP)‐aryl diazonium salt modified glassy carbon (GC) electrode where transduction is achieved using electrochemical impedance spectroscopy (EIS). GC electrodes were first modified with 4‐aminophenyl (Ph‐NH₂) layers to which AuNPs were attached. Thereafter an oligo(ethylene glycol) (OEG‐COOH) species were covalently attached to the remaining free amine groups on the Ph‐NH₂ surface. The AuNP surfaces were further modified with Ph‐NH₂ followed by attachment of a glycosylated pentapeptide (GPP), an analogon to HbA1c. Exposure of this interface to anti‐HbA1c IgG resulted in a change in charge transfer resistance (R_ct) due to the anti‐HbA1c IgG selectively complexing to the surface bound GPP. To detect the amount of HbA1c, a competitive inhibition assay was employed where the surface bound GPP and HbA1c in solution compete for the anti‐HbA1c IgG antibodies. The higher the concentration of HbA1c, the less antibody binds to the sensing interface and the lower the change of R_ct. The response of the immunosensor is linear with the HbA1c% of total haemoglobin in the range of 0%–23.3%. This competitive inhibition assay can be used for the detection of HbA1c in human blood. The performance of the immunosensor for detection of HbA1c in human blood is comparable to the clinical laboratory method.     

Synthesis,spectral investigation and development of tetrahedral copper(II) complexes as artificial metallonucleases and antimalarial agents

Seven new copper(II) complexes of type [Cu(A)(L)]?H₂O (A = sparfloxacin, ciprofloxacin, levofloxacin, gatifloxacin, pefloxacin, ofloxacin, norfloxacin; L = 5‐[(3‐chlorophenyl)diazenyl]‐4‐hydroxy‐1,3‐thiazole‐2(3H)‐thione) were synthesized and characterized using elemental and thermogravimetric analyses, and electronic, electron paramagnetic resonance (EPR), Fourier transform infrared and liquid chromatography–mass spectroscopies. Tetrahedral geometry around copper is assigned in all complexes using EPR and electronic spectral analyses. All complexes were investigated for their interaction with herring sperm DNA utilizing absorption titration (K_b = 1.27–3.13 × 10⁵ M^?1) and hydrodynamic volume measurement studies. The studies suggest the classical intercalative mode of DNA binding. The cleavage reaction on pUC19 DNA was monitored by agarose gel electrophoresis. The results indicate that the Cu(II) complexes can more effectively promote the cleavage of plasmid DNA. The superoxide dismutase mimic activity of the complexes was evaluated by nitroblue tetrazolium assay, and the complexes catalysed the dismutation of superoxide at pH = 7.8 with IC₅₀ values in the range 0.597–0.900 μM. The complexes were screened for their in vitro antibacterial activity against five pathogenic bacteria. All the complexes are good cytotoxic agents and show LC₅₀ values ranging from 5.559 to 11.912 µg ml^?1. All newly synthesized Cu(II) complexes were also evaluated for their in vitro antimalarial activity against Plasmodium falciparum strain (IC₅₀ = 0.62–2.0 µg ml^?1). Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and characterization of fluorescent copolymer containing rare earth metal complex and its interaction with DNA

A complex of Eu³⁺, acrylic acid (AA), and 1, 10‐phenanthroline (Phen) was synthesized. The structure and fluorescence of Eu(AA)₃Phen was characterized with elemental analysis, FTIR, ¹H NMR, and fluorescence spectroscopy. A novel copolymer containing rare earth complex, poly(PEGMA‐co‐NIPAm‐co‐Eu(AA)3Phen) (PPNEu), was prepared by free radical copolymerization in methanol with azodiisobutyronitrile as initiator. ¹H NMR, fluorescence spectroscopy, UV‐vis spectroscopy, and TEM were used to characterize this copolymer. The interaction of PPNEu with deoxyribonucleic acid (DNA) was studied by fluorescence spectroscopy, UV‐vis spectroscopy and agarose gel electrophoresis. The results of fluorescence, UV‐vis absorption, and agarose electrophoresis indicated that the PPNEu could interact with DNA in an electrostatic bonding mode. The TEM observation showed that the PPNEu could form spherical micelles in water solution small than 100 nm; the efficient complexation of PPNEu with DNA occurred. These results suggested the potential of the PPNEu as gene detective reagent and gene delivery carrier. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Novel 3‐Hydroxy‐2‐naphthoic hydrazone and Ni(II), Co(II) and Cu(II) Complexes: Synthesis,Spectroscopic Characterization,Antimicrobial, DNA Cleavage and Computational Studies

A novel hydrazone ligand derived from condensation reaction of 3‐hydroxy‐2‐naphthoic hydrazide with dehydroacetic acid, and its Ni(II), Cu(II) and Co(II) complexes were synthesized, characterized by spectroscopic, elemental analyses, magnetic susceptibility and conductivity methods, and screened for antimicrobial, DNA binding and cleavage properties. Spectroscopic analysis and elemental analyses indicated the formula, [MLCl₂], for the complexes; square planar geometry for the nickel, and tetrahedral geometry for copper and cobalt complexes. The non‐electrolytic natures of the complexes in Dimethyl Sulphoxide (DMSO) were confirmed by their molar conductance values in the range of 6.11–14.01 Ω^?1cm²mol^?1. The copper complex had the best antibacterial activity against Staphylococcus aureus (ATCC 29213). DNA cleavage activities of the compounds, evaluated on pBR322 DNA, by agarose gel electrophoresis, in the presence and absence of oxidant (H₂O₂) and free radical scavenger (DMSO), indicated no activity for the ligand, and moderate activity for the complexes, with the copper complex cleaving pBR322 DNA more efficiently in the presence of H₂O₂. When the complexes were evaluated for antibacterial and A‐DNA activity using Molecular docking technique, the copper complex was found to be most effective against Gram‐positive (S. aureus) bacteria. [CuLCl₂] showed good hydrogen bonding interaction with the major‐groove (C₂^.G₁₃ base pair) of A‐DNA. Density functional theory (DFT) calculations of the structural and electronic properties of the complexes revealed that [CuLCl₂] had a smaller HOMO‐LUMO gap, suggesting a higher tendency to donate electrons to electron‐accepting species of biological targets.     

Interaction of unmodified and partially silylated nanosilica with red blood cells

Interaction of red blood cells (RBCs) with unmodified and partially (50%) silylated fumed silica A-300 (nanosilica)was studied by microscopic, XRD and thermally stimulated depolarisation current (TSDC) methods. Nanosilica at a low concentration C _A-300 < 0.01 wt.% in buffered aqueous suspension is characterised by a weak haemolytic effect on RBCs. However, at C _A-300 = 1 wt% all RBCs transform into shadow corpuscles because of 100% haemolysis. Partial (one-half) hydrophobization of nanosilica leads to reduction of the haemolytic effect in comparison with unmodified silica at the same concentrations. A certain portion of the TSDC spectra of the buffered suspensions with RBC/A-300 is independent of the amounts of silica. However, significant portions of the low-and high-temperature TSDC bands have a lower intensity at C _A-300 = 1 wt% than that for RBCs alone or RBC/A-300 at C _A-300 = 0.01 wt.% because of structural changes in RBCs. Results of microscopic and XRD investigations and calculations using the TSDC-and NMR-cryoporometry suggest that the intracellular structures in RBCs (both organic and aqueous components) depend on nanosilica concentration in the suspension.      

三齿多吡啶钴(II)配合物的合成、表征及其与DNA的相互作用研究

合成了两种三齿多吡啶钴(II)配合物 (A)和[Co(H₂Bzimpy)₂]Cl₂ (B), 用元素分析、IR对配合物的组成和结构进行了表征, 测定了配合物A的晶体结构. 用电子吸收光谱、荧光光谱、循环伏安法及凝胶电泳实验等方法研究了配合物与DNA的相互作用. 结果表明配合物A和B与小牛胸腺(CTDNA)的作用属部分插入和静电结合, 凝胶电泳实验表明配合物A在310 nm光辐射15 min, 可使超螺旋pBR322DNA断裂为开环缺口型和线型DNA.     

Homo‐ and heteropolynuclear copper(II) complexes containing a new diimine–dioxime ligand and 1,10‐phenanthroline: synthesis,characterization, solvent‐extraction studies,catalase‐like functions and DNA cleavage abilities

A series of homo‐, heterodinuclear and homotrinuclear copper(II) complexes containing a new Schiff base ligand and 1,10‐phenanthroline were synthesized. Based on results of elemental analyses, FTIR, ¹H‐ and ¹³C‐NMR spectra, conductivity measurements and magnetic susceptibility measurements, the complexes had general compositions {[Cu(L)(H₂O)M(phen)₂](ClO₄)₂ [M = Cu(II), Mn(II), Co(II)]} and {[Cu₃(L)₂(H₂O)₂](ClO₄)₂}. The metal:L:phen ratio is 2:1:2 for the dinuclear copper(II) complexes and the metal:L ratio was 3:2 for the trinuclear copper(II) complex. The liquid–liquid extraction of various transition metal cations [Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II), Hg(II)] from the aqueous phase to the organic phase was carried out using the diimine–dioxime ligand. It was concluded that the ligand can effectively be used in solvent extraction of copper(II) from the aqueous phase to the organic phase. Furthermore, catalytic activitiy of the complexes for the disproportionation of hydrogen peroxide was also investigated in the presence of imidazole. Dinuclear copper(II)–manganese(II) complex has some similarity to manganese catalase in structure and activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis; we found that the homo‐ and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms in the presence of H₂O₂. Copyright © 2009 John Wiley & Sons, Ltd.     

DNA Cleavage Promoted by Cu^2＋ Complex of N,N＇-Bis（2-aminoethyl）-2,6-pyridinedicarboxamide

The interaction of Cu^2＋ complex of N,N＇-bis（2-aminoethyl）-2,6-pyridinedicarboxamide （BAP） with DNA was studied by agarose gel electrophoresis analysis. The results indicate that the BAP-Cu^2＋ complex can promote the cleavage of phosphodiester bond of supercoiled DNA at physiological condition, which is 3.2 × 10^6 times higher than DNA natural degradation. A hydrolytic cleaving mechanism through the cooperation of copper ions and functional amino groups was proposed.     

基于NMR技术的溶菌酶在琼脂糖凝胶中的动力学研究

运用脉冲梯度场测量自扩散系数及自旋自旋弛豫时间测量核磁共振技术对鸡蛋清溶菌酶(HEWL)在琼脂糖凝胶中的动力学进行了研究.试验结果表明,HEWL在琼脂糖凝胶中的自扩散系数及自旋自旋弛豫时间较其在纯乙酸钠溶液中变小,说明琼脂糖凝胶的三维网状结构使HEWL分子整体运动及局部运动都受到阻碍.并且随着琼脂糖浓度的增大,凝胶网孔尺寸不断减小,HEWL分子运动受限程度加剧,从而蛋白质分子可以较长时间内停留在高浓度区,分子间更容易互相碰撞,发生反应,晶核生长得以促进.同时琼脂糖凝胶较小流体力学网孔尺寸抑制聚晶或沉淀的出现,晶体质量获得提高.     

Copper(II) complexes of acylhydrazones: synthesis,characterization and DNA interaction

Two new acylhydrazone copper(II) complexes of 4‐hydroxy‐N′‐[(1E)‐1‐(4‐methylphenyl)ethylidene]benzohydrazide (HL¹) and 4 ethyl [4‐({(2E)‐2‐[1‐(4‐methylphenyl)ethylidene]hydrazinyl}carbonyl)phenoxy]acetate (HL²) have been synthesized and characterized. The structures of both acylhydrazone and copper(II) complexes were identified by elemental analysis, infrared spectra, UV–visible electronic absorption spectra, magnetic susceptibility measurements, TGA and powder X‐ray diffraction. DNA binding and DNA cleavage activities of the synthesized copper complexes were examined by using UV‐visible titration and agarose gel electrophoresis, respectively. The effect of complex concentration on the DNA cleavage reactions in the absence and presence of H₂O₂ was also investigated. The results indicate that all the complexes bind slightly to calf thymus DNA and cleavage pBR322 DNA. The mechanistic studies demonstrate that a hydrogen peroxide‐derived species and singlet oxygen (¹O₂) are the active oxidative species for DNA cleavage. Copyright © 2013 John Wiley & Sons, Ltd.     

Study on porous silk fibroin materials: 3. Influence of repeated freeze–thawing on the structure and properties of porous silk fibroin materials

The influence of repeated freeze–thawing on pore structural characteristics and physical properties of porous silk fibroin materials prepared by freeze drying were studied. It showed that when quick‐frozen silk fibroin solution was repeatedly thawed and frozen before being vacuum dried, thus pore size of prepared porous silk fibroin materials increased from 67 µm to about 120 µm, and pore density decreased from 80 per square millimeter to about 28 per square millimeter; at the same time compression ratio and moisture permeability increased from 22.7% and 230 g/m² hr to about 33.7% and 308 g/m² hr, respectively, tensile strength and dissolvability in hot water decreased from 20.2 N/cm² and 42.7% to about 12.5 N/cm² and 26.1%, respectively. Both the times of repeated thawing and the thawing temperature had a certain influence on the above‐mentioned pore characteristic parameters and physical properties. Copyright © 2001 John Wiley & Sons, Ltd.     

Size‐Tunable Highly Luminescent SiO2 Particles Impregnated with Number‐Adjusted CdTe Nanocrystals

Highly luminescent SiO₂ particles impregnated with CdTe nanocrystals (NCs) are prepared by a sol–gel procedure. Partial ligand exchange from thioglycolic acid to 3‐mercaptopropyltrimethoxysilane (MPS) on the NCs enables retention of the initial photoluminescence (PL) efficiency of the NCs in water, while the simultaneous addition of a poor solvent (ethanol) results in regulated assembly of the NCs through condensation of hydrolyzed MPS. The SiO₂ particles thus prepared have, for example, a diameter of 16 nm and contain three NCs each. The PL efficiency of these particles is 40 %, while the initial efficiency is 46 % in a colloidal solution. The redshift and narrowed spectral width in PL observed after impregnation indicate that the concentration of NCs in these nearly reaches the ultimate value (on the order of 10²¹ particles per liter). The porosity of these particles is investigated by means of N₂ adsorption–desorption isotherms. Due to the SiO₂ shell, these particles have higher stability in phosphate‐buffered saline buffer solution than the initial NCs. Their potential use for labeling in bio‐applications is investigated by conjugating biotinylated immunoglobulin G to them by using streptavidin maleimide as linker. Successful conjugation is confirmed by electrophoresis in agarose gel. This preparation method is an important step towards fabricating intensely emitting biocompatible SiO₂ particles impregnated with semiconductor NCs.