Huan-Tsung Chang

Publications (176)734.6 Total impact

• Article: Synthesis of Photoluminescent Au NDs-PNIPAM Hybrid Microgel for the Detection of Hg(2+)

  Li-Yi Chen, Chung-Mao Ou, Wei-Yu Chen, Chih-Ching Huang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: Poly(N-isopropylacrylamide) microgels (PNIPAM MGs) incorporated with photoluminescent gold nanodots (Au NDs) have been prepared and employed for the detection of mercury ions (Hg2(+)). Each of the PNIPAM MGs (hydrodynamic diameter 615 ± 15 nm) contains several Au NDs (diameter 1.8 ± 0.2 nm) in the Au NDs-PNIPAM MGs. Like Au NDs, Au NDs-PNIPAM MGs exhibit an absorption band at 375 nm that is assigned for ligand to metal charge transfer mixed with metal centered (ds/dp) states and photoluminescence at 520 nm originated from Au ND/polynuclear gold (I)-thiolate (core/shell) complexes. Purification of Au NDs-PNIPAM MGs relative to Au NDs is much easier through a simple centrifugation/wash process. Based on Hg2(+) induced photoluminescence quenching due to the formation of Au-Hg amalgam and formation of Au NDs-PNIPAM MGs aggregates, the signal response of Au NDs-PNIPAM MGs against Hg2(+) concentration is linear over a range from 2 to 20 nM (r = 0.9945). This selective approach provides limits of detection for Hg2(+) (at a signal-to-noise ratio of 3) of 1.9 and 1.7 nM in phosphate buffer solutions (5 mM, pH 7.0) with and without containing 500 mM NaCl, respectively. This selective and sensitive Au NDs-PNIPAM MG probe has been applied to the determination of the concentration of Hg in a representative fish sample, showing its practical potential for monitoring of Hg levels in complicated biological and environmental samples.
  ACS Applied Materials & Interfaces 04/2013; · 4.53 Impact Factor
• Article: Fibrinolysis and thrombosis of fibrinogen-modified gold nanoparticles for detection of fibrinolytic-related proteins.

  Jyun-Wei Jian, Wei-Chane Chiu, Huan-Tsung Chang, Pang-Hung Hsu, Chih-Ching Huang
  [show abstract] [hide abstract]
  ABSTRACT: Fibrinolysis (plasmin-mediated cleavage of fibrin structures) is a process in which fibrin clots can be removed from blood vessels, allowing the return of normal vascular function. Although several methods have been developed to measure plasmin activity and plasminogen (the plasmin precursor) concentrations, they are only moderately sensitive and quantitative and require large amounts of reagents, limiting their applicability. We developed two simple, label-free homogeneous assays using gold nanoparticles (Au NPs) for detection of fibrinolysis-related proteins and their activator (urokinase that converts plasminogen to plasmin) and inhibitor (α2-plasmin inhibitor that inhibits plasmin and plasminogen bound to fibrin). We used a fibrinolysis-based sensor, based on plasmin-mediated cleavage of fibrinogen-modified Au NPs (Fib-Au NPs) leading to aggregation of Au NPs, to determine plasmin activity in a biological medium mimic solution. A combination of thrombin (Thr) and Fib-Au NPs allowed us to analyze plasmin activity and plasminogen concentrations in serum through Thr-induced agglutination of Fib-Au NPs. The limit of detection (LOD; S/N=3) of this sensor for plasmin in serum was 0.4nM (ca. 1.7×10(-4)unitmL(-1)). These label-free assays offer several advantages over conventional assays, including allowing rapid and simple readings with the naked eye or measurement by UV-vis absorption spectroscopy.
  Analytica chimica acta 04/2013; 774:67-72. · 4.31 Impact Factor
• Article: Te/Pt nanonetwork modified carbon fiber microelectrodes for methanol oxidation.

  Hsiang-Yu Tsai, Zih-Yu Shih, Zong-Hong Lin, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: Te/Pt nanonetwork-decorated carbon fiber microelectrodes (CFMEs) have been fabricated and employed as anodic catalysts in a direct methanol fuel cell (DMFC). Te nanowires were prepared from tellurite ions (TeO3(2-)) through a seed-mediated growth process and were deposited onto CFMEs to form three-dimensional Te nanonetworks. The Te nanonetworks then acted as a framework and reducing agent to reduce PtCl6(2-) ions to form Te/Pt through a galvanic replacement reaction, leading to the formation of Te/PtCFMEs. By controlling the reaction time, the amount of Pt and morphology of Te/Pt nanonetworks were controlled, leading to various degrees of electrocatalytic activity. The Te/PtCFMEs provide a high electrochemical active surface area (129.2 m(2) g(-1)), good catalytic activity (1.2 A mg(-1)), high current density (20.0 mA cm(-2)), long durability, and tolerance toward the poisoning species for methanol oxidation in 0.5 M sulfuric acid containing 1 M methanol. We have further demonstrated an enhanced current density by separately using 3 and 5 Te/PtCFMEs. Our results show that the low-cost, stable, and effective Te/PtCFMEs have great potential in the fabrication of cost-effective fuel cells.
  Nanotechnology 04/2013; 24(19):195402. · 3.98 Impact Factor
• Article: Using Surface-Assisted Laser Desorption/Ionization Mass Spectrometry to Detect ss- and ds-Oligodeoxynucleotides.

  Wen-Tsen Chen, Ming-Feng Huang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: We applied surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) with HgTe nanostructures as the matrix for the detection of single- and double-stranded oligodeoxynucleotides (ss-ODNs and ds-ODNs). The concentrations of surfactant and additives (metal ions, an amine) and the pH and ionic strength of the sample matrix played significantly different roles in the detection of ss- and ds-ODNs with various sequences. In the presence of Brij 76 (1.5 %), Hg(2+) (7.5 μM), and cadaverine (10 μM) at pH 5.0, this SALDI-MS approach allowed the simultaneous detection of T15, T20, T33, and T40, with limits of detection at the femtomole-to-picomole level and sample-to-sample intensity variation <23 %. In the presence of Ag(+) (1 μM) and cadaverine (10 μM) at pH 7.0, this technique allowed the detection of randomly sequenced ss- and ds-ODNs at concentrations down to the femtomole level. To the best of our knowledge, this paper is the first to report the detection of ss-ODNs (up to 50-mer) and ds-ODNs (up to 30 base pairs) through the combination of SALDI-MS with HgTe nanostructures as matrices. We demonstrated the practicality of this approach through analysis of a single nucleotide polymorphism that determines the fate of the valine residue in the β-globin of sickle cell megaloblasts.
  Journal of the American Society for Mass Spectrometry 03/2013; · 4.00 Impact Factor
• Source

  Available from: Lin-Chen Ho

  Dataset: Sensitive pH probes of retro-self-quenching fluorescent nanoparticles

  Lin-Chen Ho, Chung-Mao Ou, Chi-Lin Li, Ssu-Yu Chen, Hung-Wen Li, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: Polymeric fluorescent nanoparticles, R6GDARs, containing rhodamine 6G within 1,3-phenylenediamine resin are prepared using the extensive Stöber method. The R6GDAR is capable of sensing intracellular pH in living cells, with the fluorescence intensity increasing upon decreasing the pH values from 8.0 to 3.0. This fluorescence enhancement at low pH is based on the "retro-self-quenching" mechanism, where the protonation of the R6GDAR backbones expands the particle structure, leading to increase in the separation among concentrated R6G molecules as well as their release. Fluorescence time-course measurement shows that even individual R6GDARs have high sensitivity to report the environmental pH at the single particle level. Compared to other existing pH sensors, R6GDARs offer a wider working pH range (5 pH units), higher sensitivity, and greater photostability. R6GDARs have been demonstrated to be sensitive to map local pH values inside MCF7 and MDA-MB-231 cells, with extremely low cell toxicity. R6GDARs serve as an excellent pH sensing probe for cellular microenvironments.
• Article: Quantitative surface-assisted laser desorption/ionization-MS approaches for bioanalysis.

  Cho-Chun Hu, Ming-Feng Huang, Huan-Tsung Chang
  Bioanalysis 03/2013; 5(6):633-5. · 3.22 Impact Factor
• Article: Highly efficient inhibition of human immunodeficiency virus type 1 reverse transcriptase by aptamers functionalized gold nanoparticles.

  Yen-Chun Shiang, Chung-Mao Ou, Shih-Ju Chen, Ting-Yu Ou, Han-Jia Lin, Chih-Ching Huang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: We have developed aptamer (Apt)-conjugated gold nanoparticles (Apt-Au NPs, 13 nm in diameter) as highly effective inhibitors for human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT). Two Apts, RT1t49 (Apt(pol)) and ODN 93 (Apt(RH)), which recognize the polymerase and RNase H regions of HIV-1 RT, are used to conjugate Au NPs to prepare Apt(pol)-Au NPs and Apt(RH)-Au NPs, respectively. In addition to DNA sequence, the surface density of the aptamers on Au NPs (nApt-Au NPs; n is the number of aptamer molecules on each Au NP) and the linker length number (T(m); m is the base number of the deoxythymidine linker) between the aptamer and Au NPs play important roles in determining their inhibition activity. A HIV-lentiviral vector-based antiviral assay has been applied to determine the inhibitory effect of aptamers or Apt-Au NPs on the early stages of their replication cycle. The nuclease-stable G-quadruplex structure of 40Apt(RH)-T(45)-Au NPs shows inhibitory efficiency in the retroviral replication cycle with a decreasing infectivity (40.2%).
  Nanoscale 02/2013; · 5.91 Impact Factor
• Article: Photoluminescent C-dots@RGO Probe for Sensitive and Selective Detection of Acetylcholine.

  Chen-I Wang, Arun Prakash Periasamy, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: We have developed a sensitive and selective photoluminescence (PL)-quenching assay for the detection of acetylcholine (ACh) using reduced graphene oxide decorated with carbon dots (C-dots@RGO). The highly stable C-dots@RGO synthesized from catechin and graphene oxide through a hydrothermal reaction displays excitation-wavelength dependence of PL. Acetylcholinesterase (AChE) converts ACh to choline, which in turn is oxidized by choline oxidase (ChOx) to produce betaine and H2O2 that generates the reactive oxygen species (ROS). The as-produced ROS induces PL quenching of the C-dots@RGO through an etching process. With respect to the sensitivity, the optimal reaction/sensing temperature and pH are at 37 ˚C and 9.0, respectively, using C-dots@RGO (0.4 mg mL-1) and AChE and ChOx at the activities of 0.5 and 0.1 U mL-1, respectively. The PL intensity (excitation/emission wavelengths 365/440 nm) of the C-dots@RGO is inversely proportional to the concentration of ACh over a range of 0.05-10 nM (r = 0.997), with a limit of detection (signal-to-noise ratio 3) of 30 pM. We have validated this assay by the determination of the concentrations of ACh in plasma and blood samples, with results of 2.6 ± 0.8 nM (n = 5) and 6.8 ± 0.4 nM (n = 5), respectively. Our study opens an avenue for the detection of various analytes using C-dots@RGO in conjunction with different enzymes, substrates, and/or inhibitors.
  Analytical Chemistry 02/2013; · 5.86 Impact Factor
• Article: Analysis of the Formation Process of Gold Nanoparticles by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry.

  Iva Tomalová, Chia-Hsin Lee, Wen-Tsen Chen, Cheng-Kang Chiang, Huan-Tsung Chang, Jan Preisler
  [show abstract] [hide abstract]
  ABSTRACT: Chemical reactions of reducing agents in the gold nanoparticle (AuNP) formation process were characterized using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). As the reaction of the AuNPs progresses, the produced AuNPs can serve as an efficient SALDI substrate. SALDI-MS revealed that the reducing agents and their oxidation products can be determined in the mass spectra. With respect to the transmission electron microscopic and UV-Vis spectroscopic examination of AuNPs, SALDI-MS results confirm not only the tendency toward AuNPs formation, but also reflect the information of the redox reaction process. Our results provide useful information for developing SALDI-MS methods to explore the chemical information regarding the surface behavior between adsorbates and nanomaterials.
  Journal of the American Society for Mass Spectrometry 01/2013; · 4.00 Impact Factor
• Source

  Available from: Han-Jia Lin

  Article: Using photoluminescent gold nanodots to detect hemoglobin in diluted blood samples.

  Li-Yi Chen, Chih-Ching Huang, Wei-Yu Chen, Han-Jia Lin, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: In this study we used photoluminescent 11-mercaptoundecanoic acid-bound gold nanodots (11-MUA-Au NDs) to detect hemoglobin through photoluminescence (PL) quenching. The mechanism of quenching, which occurred through redox reactions between the 11-MUA-Au NDs and the Fe(II) atoms of hemin units, was supported by an increase in the signals (G 2.0 and 5.9) of high-spin state Fe(III) ions. The Stern-Volmer quenching constants (K(sv)) for hemin, cytochrome c, hemoglobin, and myoglobin were 5.6×10(7), 1.7×10(7), 1.6×10(7), and 6.2×10(6)M(-1), respectively, in good agreement with the order of their reduction potentials. When excited at 375nm, the PL intensity of the 11-MUA-Au NDs at 520nm decreased upon increasing the concentration of hemoglobin from 1.0 to 10nM (R(2)=0.9913). This approach using bovine serum albumin blocked 11-MUA-Au NDs provided a limit of detection for hemoglobin (at a signal-to-noise ratio of 3) of 0.5nM in biological buffer, with great selectivity over other non-heme-containing proteins, including human serum albumin, β-casein, and carbonic anhydrase. We validated the practicality of this approach through the determination of the concentrations (1.85-2.46mM) of hemoglobin in diluted (10(6)-fold) human blood samples based on PL quenching of Au NDs. This simple, sensitive, and selective approach holds great potential for the diagnosis of several diseases, including anemia, erythrocytosis, and thalassemias.
  Biosensors & bioelectronics 12/2012; 43C:38-44. · 5.43 Impact Factor
• Article: Enzyme Mimics of Au/Ag Nanoparticles for Fluorescent Detection of Acetylcholine.

  Chen-I Wang, Wen-Tsen Chen, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: We have developed a highly sensitive and selective fluorescent assay for the detection of acetylcholine (ACh) based on enzyme mimics of Au/Ag nanoparticles (NPs). These NPs were prepared via a one-step solution phase reaction between 13-nm Au NPs and Ag+ ions in the presence of stabilizing agents such as adenosine triphosphate (ATP) and polyethylene glycol (PEG). Our sensing strategy involves reacting ACh with acetylcholinesterase (AChE) to form choline that is in turn oxidized by choline oxidase (ChOx) to produce betaine and H2O2, which reacts with Amplex UltraRed (AUR) in the presence of bimetallic NPs catalyst to form a fluorescent product. The fluorescence intensity (excitation/emission wavelengths of 540/592 nm) is proportional to the concentration of ACh over a range of 1-100 nM (R2 = 0.998), with a limit of detection of 0.21 nM (signal/noise = 3). When compared with Au NPs and horseradish peroxidase, the Au/Ag NPs provide 150- and 115-fold higher catalytic activity toward the H2O2-mediated AUR reaction. The practicality of the assay has been validated by determining the concentrations of ACh in plasma and blood samples, with results of 2.69 ± 0.84 nM (n = 5) and 6.75 ± 1.42 nM (n = 5), respectively. Thus the present assay holds great potential for the analysis of ACh in biological samples.
  Analytical Chemistry 10/2012; · 5.86 Impact Factor
• Article: Iron telluride nanorods-based system for the detection of total mercury in blood.

  Prathik Roy, Zong-Hong Lin, Chi-Te Liang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: We have developed a simple, colorimetric iron telluride (FeTe) nanorods (NRs) based system for the detection of mercury, mainly based on the cation exchange reaction between FeTe NRs and Hg(2+). FeTe NRs (length, 105±21nm) react with Hg(2+) to form HgTe NRs (length, 112±26nm) and consequently release Fe(2+) ions that catalyzes the oxidation between a peroxidase substrate 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) and H(2)O(2). The concentration of Fe(2+) and thereby Hg(2+) can be determined by measuring the absorbance of the ABTS oxidized product at 418nm. This approach allows the detection of Hg(2+), with a limit of detection of 1.31nM at a signal-to-noise ratio 3 and a linear range 5-100nM (R(2)=0.99). The low-cost, simple, sensitive, and reproducible assay has been validated for the detection of Hg(2+) in a blood sample (SRM 955c), with the result being in good agreement with that provided by National Institute of Standards and Technology.
  Journal of hazardous materials 10/2012; · 4.14 Impact Factor
• Article: Peroxidase mimicking DNA-gold nanoparticles for fluorescence detection of the lead ions in blood.

  Chi-Lin Li, Chih-Ching Huang, Wei-Hsi Chen, Cheng-Kang Chiang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: Oligonucleotide (T30695) modified gold nanoparticles (T30695-Au NPs) have been prepared and employed for quantification of lead ions (Pb(2+)) in blood. The detection of Pb(2+) ions is through the formation of Au-Pb alloys and oligonucleotide-Pb(2+) complexes that catalyze the H(2)O(2)-mediated oxidation of non-fluorescent Amplex UltraRed (AUR) to form a highly fluorescent oxidized AUR product. Surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) and inductively coupled plasma mass spectrometry (ICP-MS) revealed the formation of Au-Pb alloys on the surfaces of the 40T30695-Au NPs (i.e., the system featuring 40 molecules of T30695 per Au NP) in the presence of Pb(2+) ions, leading to increased catalytic activity for the H(2)O(2)-mediated oxidation of AUR. The fluorescence intensity (excitation/emission maxima: ca. 540/584 nm) of the oxidized AUR product is proportional to the concentration of Pb(2+) ions over the range 0.1-100 nM, with a linear correlation (R(2) = 0.99). The 40T30695-Au NP/AUR probe is highly selective toward Pb(2+) ions (by at least 200-fold over other tested metal ions). The 40T30695-Au NPs/AUR probe provided limits of detection (LOD, at a signal-to-noise ratio 3) for Pb(2+) ions of 0.05 and 0.1 nM, in Tris-acetate solution (5 mM, pH 8.0) without and with salt (150 mM NaCl, 5 mM KCl, 1 mM MgCl(2), and 1 mM CaCl(2)), respectively. Without conducting tedious sample pretreatment, the approach allows detection of Pb(2+) ions in blood samples, showing the potential of the 40T30695-Au NPs/AUR assay for on-site and real-time detection of Pb(2+) ions in biological samples.
  The Analyst 10/2012; 137(22):5222-8. · 4.23 Impact Factor
• Article: Catalytic gold nanoparticles for fluorescent detection of mercury(II) and lead(II) ions.

  Chen-I Wang, Chih-Ching Huang, Yang-Wei Lin, Wen-Tsen Chen, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: In this study, we developed a fluorescence assay for the highly sensitive and selective detection of Hg(2+) and Pb(2+) ions using a gold nanoparticle (Au NP)-based probe. The Hg-Au and Pb-Au alloys that formed on the Au NP surfaces allowed the Au NPs to exhibit peroxidase-mimicking catalytic activity in the H(2)O(2)-mediated oxidation of Amplex UltraRed (AUR). The fluorescence of the AUR oxidation product increased upon increasing the concentration of either Hg(2+) or Pb(2+) ions. By controlling the pH values of 5mM tris-acetate buffers at 7.0 and 9.0, this H(2)O(2)-AUR-Au NP probe detected Hg(2+) and Pb(2+) ions, respectively, both with limits of detection (signal-to-noise ratio: 3) of 4.0 nM. The fluorescence intensity of the AUR oxidation product was proportional to the concentrations of Hg(2+) and Pb(2+) ions over ranges 0.05-1 μM (R(2)=0.993) and 0.05-5 μM (R(2)=0.996), respectively. The H(2)O(2)-AUR-Au NP probe was highly selective for Hg(2+) (>100-fold) and Pb(2+) (>300-fold) ions in the presence of other tested metal ions. We validated the practicality of this simple, selective, and sensitive H(2)O(2)-AUR-Au NP probe through determination of the concentrations of Hg(2+) and Pb(2+) ions in a lake water sample and of Pb(2+) ions in a blood sample. To the best of our knowledge, this system is the first example of Au NPs being used as enzyme-mimics for the fluorescence detection of Hg(2+) and Pb(2+) ions.
  Analytica chimica acta 10/2012; 745:124-30. · 4.31 Impact Factor
• Article: Peroxidase mimicking DNA–gold nanoparticles for fluorescence detection of the lead ions in blood

  Chi-Lin Li, Chih-Ching Huang, Wei-Hsi Chen, Cheng-Kang Chiang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: Oligonucleotide (T30695) modified gold nanoparticles (T30695–Au NPs) have been prepared and employed for quantification of lead ions (Pb2+) in blood. The detection of Pb2+ ions is through the formation of Au-Pb alloys and oligonucleotides-Pb2+ complexes that catalyze the H2O2-mediated 10 oxidation of non-fluorescent Amplex UltraRed (AUR) to form a highly fluorescent oxidized AUR product. Surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) and inductively coupled plasma mass spectrometry (ICP-MS) revealed the formation of Au-Pb alloys on the surfaces of the 40T30695–Au NPs (i.e., the system featuring 40 molecules of T30695 per Au NP) in the presence of Pb2+ ions, leading to increased catalytic activity for the H2O2-mediated oxidation of AUR. 15 The fluorescence intensity (excitation/emission maxima: ca. 540/584 nm) of the oxidized AUR product is proportional to the concentration of Pb2+ ions over a range 0.1–100 nM, with a linear correlation (R2 = 0.99). The 40T30695–Au NP/AUR probe is highly selective toward Pb2+ ions (by at least 200-fold over other tested metal ions). The 40T30695–Au NPs/AUR probe provided limits of detection (LOD, at a signalto- noise ratio 3) for Pb2+ ions of 0.05 and 0.1 nM, in Tris-acetate solution (5 mM, pH 8.0) without and 20 with containing salt (150 mM NaCl, 5 mM KCl, 1 mM MgCl2, and 1 mM CaCl2), respectively. Without conducting tedious sample pretreatment, the approach allows detection of Pb2+ ions in blood samples, showing the potential of the 40T30695–Au NPs/AUR assay for on-site and real-time detection of Pb2+ ions in biological sample.
  Analyst. 09/2012;
• Article: Preparation of photocatalytic au-ag(2) te nanomaterials.

  Zong-Hong Lin, Zih-Yu Shih, Prathik Roy, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: A facile approach has been developed for the preparation of various morphologies of Au-Ag(2) Te nanomaterials (NMs) that exhibit strong photocatalytic activity. Te NMs (nanowires, nanopencils, and nanorice) were prepared from TeO(2) in the presence of various concentrations (16, 8, and 4 M) of a reducing agent (N(2) H(4) ) at different temperatures (25 and 60 °C). These three Te NMs were then used to prepare Au-Ag(2) Te NMs by spontaneous redox reactions with Au(3+) and Ag(+) ions sequentially. The Au-Ag(2) Te nanopencils exhibit the highest activity toward degradation of methylene blue and formation of active hydroxyl radicals on solar irradiation, mainly because they absorb light in the visible region most strongly. All three differently shaped Au-Ag(2) Te NMs (10 μg mL(-1) ) provide a death rate of Escherichia coli greater than 80 % within 60 min, which is higher than that of 51 % for commercial TiO(2) nanoparticles (100 μg mL(-1) ). Under light irradiation, the Au NPs in Au-Ag(2) Te NMs enhance the overall photo-oxidation ability of Ag(2) Te NMs through faster charge separation because of good contact between Ag(2) Te and Au segments. With high antibacterial activity and low toxicity toward normal cells, the Au-Ag(2) Te NMs hold great potential for use as efficient antibacterial agents.
  Chemistry 08/2012; 18(39):12330-6. · 5.93 Impact Factor
• Article: Peroxidase-mimic bismuth-gold nanoparticles for determining the activity of thrombin and drug screening.

  Chia-Wen Lien, Chih-Ching Huang, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: Fibrinogen-modified bismuth-gold nanoparticles (Fib-Bi-Au NPs) are prepared and used as enzyme mimics for the H(2)O(2)-mediated reaction with Amplex Red (AR), which is further employed for determining thrombin activity and drug screening.
  Chemical Communications 07/2012; 48(64):7952-4. · 6.17 Impact Factor
• Article: Detection of melamine in infant formula and grain powder by surface-assisted laser desorption/ionization mass spectrometry.

  Yi-Ting Hsieh, Wen-Tsen Chen, Iva Tomalová, Jan Preisler, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: We have developed a method for the determination of melamine (MEL), ammeline (AMN), and ammelide (AMD) by surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using gold nanoparticles (Au NPs). The major peaks for MEL, AMN, and AMD at m/z 127.07, 128.05, and 129.04 are assigned to the [MEL + H](+), [AMN + H](+), and [AMD + H](+) ions. Because the three tested compounds adsorb weakly onto the surfaces of the Au NPs through Au-N bonding, they can be easily concentrated from complex samples by applying a simple trapping/centrifugation process. The SALDI-MS method provides limits of detection of 5, 10, and 300 nM for MEL, AMN, and AMD, respectively, at a signal-to-noise ratio of 3. The signal variation for 150-shot average spectra of the three analytes within the same spot was 15%, and the batch-to-batch variation was 20%. We have validated the practicality of this approach by the analysis of these three analytes in infant formula and grain powder. This simple and rapid SALDI-MS approach holds great potential for screening of MEL in foods.
  Rapid Communications in Mass Spectrometry 06/2012; 26(12):1393-8. · 2.79 Impact Factor
• Source

  Available from: ntur.lib.ntu.edu.tw

  Article: Aptamer-modified gold nanoparticles for targeting breast cancer cells through light scattering

  Yu-Fen Huang, Yang-Wei Lin, Zong-Hong Lin, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: In this study, we demonstrated the potential use of nucleic acid ligand (aptamers) conjugated gold nanoparticles (AuNPs) for cancer cell detection. Through specific binding of the aptamers toward platelet-derived growth factor (PDGF), MDA-MB-231 and Hs578T cells (cancer cells) that over-express PDGF, interact with Apt-AuNPs to a greater extent than do H184B5F5/M10 cells (normal cells). These results were confirmed through inductively coupled plasma mass spectrometry measurements of the gold ion concentrations within these cells. Aggregation of the Apt-AuNPs in the cytoplasm of the cancer cells led to the generation of an intense scattered light upon photo-illumination; this phenomenon allows the differentiation of cancer cells from normal cells using a dark field optical microscope. The presence of Apt-AuNPs suppressed the proliferation of MDA-MB-231 cancer cells, but not H184B5F5/M10 cells.
  Journal of Nanoparticle Research 04/2012; 11(4):775-783. · 3.29 Impact Factor
• Source

  Available from: nanoarchive.org

  Article: Synthesis and characterization of ZnxHg1−xSeyS1−y quantum dots

  Guo-Yu Lan, Yang-Wei Lin, Zong-Hong Lin, Huan-Tsung Chang
  [show abstract] [hide abstract]
  ABSTRACT: This article describes the synthesis of highly water-soluble Zn x Hg1−x Se y S1−y quantum dots (QDs) in aqueous solution through a simple photo-assisted reaction between ZnSe QDs and mercury(I) nitrate dihydrate [Hg2(NO3)2·2H2O]. In order to deduce the optimal synthesis conditions, we varied several parameters, including the concentrations of mercaptosuccinic acid (MSA) and Hg2(NO3)2·2H2O, the illumination time, and the reaction temperature. When irradiated at temperatures below 80°C, the ZnSe QDs reacted with the S2− ions formed rapidly from MSA and the Hg2+ ions formed from Hg2 2+ ions to form Zn x Hg1−x Se y S1−y QDs through a process of photo-etching and surface combination. Under different conditions, we prepared a series of Zn x Hg1−x Se y S1−y QDs that emit fluorescence at the maximum wavelengths ranging from 405 to 760nm. Inductively coupled plasma-mass spectrometry and transmission electron microscopy/energy dispersive spectrometry revealed that the content of Hg in the Zn x Hg1−x Se y S1−y QDs was greater when the synthesis was conducted at higher temperature. The Zn0.88Hg0.12Se0.44S0.56 QDs exhibit improved photostability than crude ZnSe QDs and possess long lifetimes (τ1~38ns and τ2~158ns). KeywordsZn x Hg1−x Se y S1−y quantum dots-Near-infrared photoluminescence-Lifetime-Photostability
  Journal of Nanoparticle Research 04/2012; 12(4):1377-1388. · 3.29 Impact Factor