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Xiao Qing Zhang, Ye Feng, Shaoyun Duan, Lingling Su, Jialin Zhang, Fengjiao He
The accurate and rapid detection of Mycobacterium tuberculosis (M. tuberculosis) is essential for the effective treatment of tuberculosis. In this article, we propose an electrochemical sensor to detect M. tuberculosis reference strain H37Rv. The sen-sor contains an H37Rv aptamer and oligonucleotides modified with gold nanoparticles (AuNPs-DNA). An H37Rv aptamer screened by our laboratory was used as the recognition probe. The change in frequency shift mediated by AuNPs-DNA in the presence of H37Rv was detected using a multichannel series piezoelectric quartz crystal (MSPQC) system...
March 22, 2019: ACS Sensors
Mingmin Li, Jianzhen Wu, Mengtian Ma, Zhichao Feng, Ze Mi, Pengfei Rong, Dingbin Liu
Surface-enhanced Raman spectroscopy (SERS) has proven a powerful tool for multiplex detection and imaging due to its narrow peak width and high sensitivity. However, conventional SERS reporters are limited to thiolated compounds, which have limitations such as chemical stability and spectral overlap. Here, we used alkyne- and nitrile-bearing molecules to directly fabricate a set of SERS tags for multiplex imaging. The alkyne and nitrile groups act as both the anchoring points to interact with gold nanoparticle (AuNP) surfaces and the reporters exhibiting strong and nonoverlapping signals in the cellular Raman-silent region...
2019: Nanotheranostics
Veena Sunderam, Devasena Thiyagarajan, Ansel Vishal Lawrence, Sathak Sameer Shaik Mohammed, Arokiyaraj Selvaraj
The aqueous cashew leaves extract obtained was investigated for the preparation of gold nanoparticle (AuNPs). The obtained AuNPs were characterized by UV-Visible spectroscopy, FTIR and XRD analysis. Results indicated that the green synthesized AuNPs showed good antibacterial effect against Escherichia coli and Bacillus subtilis and exhibited 74.47% viability on PBMC and 23.56% viability on MCF-7 cell lines at a maximum concentration of 100 µg/ml. Therefore, future studies on antibacterial application in food packing, wound dressing and antihelmintic applications will be studied...
March 2019: Saudi Journal of Biological Sciences
Ngoc-Viet Nguyen, Chun-Ping Jen
This study established a microfluidic chip for the capture of A549 human lung circulating tumor cells via the aptamer-conjugated self-assembled monolayer (SAM) of gold nanoparticles (AuNPs) in the channel. AuNPs are among the most attractive nanomaterials for the signal enhancement of biosensors owing to their unique chemical, physical, and mechanical properties. The microchip was fabricated using soft photolithography and casting and molding techniques. A self-assembly method was designed to attach AuNPs, cell-specific aptamers, and target cells onto the desired area (i...
March 19, 2019: Micromachines
Hongxiao Sun, Min Hong, Qiangqiang Yang, Chuan Li, Guangzhi Zhang, Qiaoli Yue, Yanhua Ma, Xia Li, Chen-Zhong Li
The human telomerase reverse transcriptase catalytic subunit (hTERT) is the rate-limiting subunit of the telomerase holoenzyme. Down-regulating the expression of hTERT mRNA by antisense oligonucleotides would reduce the expression of hTERT, inhibit telomerase activity, and impair the growth of cancer cells in vitro. In this work, we propose a locked nucleic acid-functionalized gold nanoparticle flare probe (AuNP-probe). After transferring these probes into cells by endocytosis of the gold nanoparticles, the binding process of the antisense locked nucleic acid with hTERT mRNA along with gene regulation can be visualized by fluorescence recovery of flare-sequences...
March 20, 2019: Analyst
Nan Yang, Tingting You, Yukun Gao, Sichen Lu, Penggang Yin
The present study demonstrated a one-step method for the first time to fabricate self-assembled gold nanoparticle (AuNP) metafilms at the water-toluene interface by adding polystyrene-polyisoprene-polystyrene as the support layer. The thiolated polyethylene glycol and ethanol were used to tune the surface charge density on the AuNPs, constructing a balanced situation at the water-toluene interface. The flexible (AuNP) metafilm can be easily obtained after evaporation of the toluene phase and further used as a surface-enhanced Raman scattering (SERS) substrate for trace thiram detection...
March 20, 2019: Langmuir: the ACS Journal of Surfaces and Colloids
Anna Dzimitrowicz, Piotr Cyganowski, Piotr Jamroz, Dorota Jermakowicz-Bartkowiak, Malgorzata Rzegocka, Agnieszka Cwiklinska, Pawel Pohl
Size-controlled gold nanoparticles (AuNPs) were synthesised with solutions of three types of Polish honeys (lime, multiflower, honeydew) and used in microwave-induced hyperthermia cancer treatment. Optical and structural properties of nanostructures were optimized in reference to measurements made by using UV/Vis absorption spectrophotometry (UV/Vis), transmission electron microscopy (TEM) supported by energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and attenuated total reflectance Fourier transformation infrared spectroscopy (ATR FT-IR)...
March 18, 2019: Materials
Satish Kumar Vemuri, Rajkiran Reddy Banala, Sudip Mukherjee, Purushotham Uppula, Subbaiah Gpv, Gurava Reddy A V, Malarvilli T
Cancer therapeutics development has been a challenge due to their untoward side effects and cytotoxicity. Phytochemical anti-cancer drugs have several advantages over chemical chemotherapeutic drugs as they are less cytotoxic and have a greater pharmacological advantage. However, lack of targeting ability limits the use of phytochemicals at a great extent for a successful therapeutic strategy. Gold nanoparticles (AuNPs) have long been used to load the therapeutic cargo and provided significant advantages over conventional chemo-therapeutics...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
P Boomi, R M Ganesan, G Poorani, H Gurumallesh Prabu, S Ravikumar, J Jeyakanthan
Greener nanotechnology plays an important role in developing alternative and effective treatment strategies for various diseases. Biological synthesis of metal nanoparticles (MNPs) has known to possess suitable alternatives than the existing chemical methods. Greener synthesis of MNPs by using plant extracts has become an emerging field due to their safe, eco-friendly and non-toxic nature that are suitable for synergistic biological activities. Hence, the greener method is chosen by the present study. In the present study, the greener synthesis of gold nanoparticles (AuNPs) was successfully done by using Coleus aromaticus leaf extract at three different temperatures (30 °C, 60 °C and 100 °C)...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
Vineeta Panwar, Suman L Jain
The present paper describes the successful synthesis and application of a ternary hybrid consists of gold nanoparticles decorated on titania-polyaniline (TiO2 -PANI-AuNPs) for A3 -coupling between aldehydes, terminal alkynes and amines under visible irradiation. The synthesis of ternary hybrid involved the coating of PANI on TiO2 via an oxidative polymerization method followed by the deposition of AuNPs on TiO2 -PANI using trisodium citrate as a reducing agent. The synthesized photocatalyst was characterized by various techniques like FT-IR, SEM, HR-TEM, XRD, UV-VIS, ICP-AES, TGA, XPS and PL spectroscopy...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
Chongning Li, Peidi Fan, Aihui Liang, Zhiliang Jiang
The highly catalytic Ca-doped carbon dots (CDCa ) were prepared by microwave procedure, that exhibit strong catalytic effect on HAuCl4 -glucose (GLC) reaction to form gold nanoparticles (AuNPs) with high SERS activity, using Victoria blue B (VBB) as a molecular probe. The SERS intensity at 1615 cm-1 increased linearly with CDCa increasing, due to formation of more AuNPs nanosol substrate as indicator. When thrombin aptamer (Apt) was added in this system, Apt adsorbed on the CDCa surface to inhibit theirs catalytic activity, and the SERS intensity decreased...
June 2019: Materials Science & Engineering. C, Materials for Biological Applications
Mauro Marengo, Gianfranco Mamone, Pasquale Ferranti, Laura Polito, Stefania Iametti, Francesco Bonomi
This work introduces a novel methodological approach to study both the geometry of complex protein networks and the nature of the interacting proteins. This approach is based on the high reactivity of Au+ ions on the surface of gold nanoparticles (AuNPs) towards thiols, that allows fast formation of a covalent bond between accessible protein thiols and AuNPs. In the case of the durum wheat semolina used in the exploratory studies reported here, the nature of proteins covalently bound to AuNPs is expected to be affected by both the compactness of the protein network and by the AuNPs size...
May 2019: Food Research International
Annalisa Scroccarello, Flavio Della Pelle, Lilia Neri, Paola Pittia, Dario Compagnone
In this work, the exploitability of rapid and easy to use methods for the evaluation of the antioxidant capacity (AOC) and sugars content (SC), through metal nanoparticles (MNPs) formation, has been proved and applied to apples. In particular, an AgNPs-based sugar quantification assays and an AuNPs-based polyphenols antioxidant capacity assay have been used as tools for the evaluation of apple extracts composition. Both assays are based on the ability of the analytes (sugars and polyphenols) to reduce the source of metal (Au3+ and Ag+ ), stabilizing, at the same time, the resulting MNPs colloidal suspensions...
May 2019: Food Research International
Wenjing Wang, Huabiao Tang, Yuan Wu, Yinli Zhang, Zhaohui Li
A non-enzymatic and highly electrocatalytic H2 O2 biosensor was proposed by using a novel electrode composed of hemin-capped biomineralized gold nanoparticles (Hem@AuNPs), reduced graphene oxide (rGO) and chitosan (CS). Owing to the excellent electrocatalytic activity of Hem@AuNPs and great conductivity of rGO, this developed biosensor is capable of ultrasensitive measuring H2 O2 in real-time. In addition, the introduction of CS resulted in a film on the electrode, which can enhance the stability by protecting the biosensor from external disturbances...
February 21, 2019: Biosensors & Bioelectronics
Weidan Chang, Weipeng Liu, Ying Liu, Fangfang Zhan, Huifang Chen, Hongtao Lei, Yingju Liu
A colorimetric method is presented for the detection of specific nucleotide sequences in plant pathogens. It is based on the use of CRISPR/Cas9-triggered isothermal amplification and gold nanoparticles (AuNPs) as optical probes. The target DNA was recognized and broken up by a given Cas9/sgRNA complex. After isothermal amplification, the product was hybridized with oligonucleotide-functionalized AuNPs. This resulted in the aggregation of AuNPs and a color change from wine red to purple. The visual detection limit is 2 pM of DNA, while a linear relationship exists between the ratio of absorbance at 650 and 525 nm and the DNA concentration in the range from 0...
March 15, 2019: Mikrochimica Acta
Dongxian Li, Shun Wang, Ling Wang, Hao Zhang, Jiandong Hu
In this study, a simple colorimetric probe was developed for rapid and highly sensitive detection of malathion based on gold nanoparticles (AuNPs) anti-aggregation mechanism. A certain amount of NaOH can cause the aggregation of citrate-stabilized AuNPs due to the electrostatic interactions, and the color of AuNP solution changes from wine-red to gray. While in the presence of malathion, malathion is easily hydrolyzed in a strong alkali environment (pH > 9), followed by the production of a mass of negative charges, and thus the aggregated AuNPs turns to well-dispersed and the color of AuNP solution changes from gray to wine-red...
March 15, 2019: Analytical and Bioanalytical Chemistry
Zheyan Chen, Tingting Wang, Mengnan Guo, Hui Chang, Huan Zhou, Ying Wang, Jiannong Ye, Qingcui Chu, Dongping Huang
In this work, citrate-capped gold-nanoparticles (citrate-AuNPs) have been firstly used for selective extraction of trace polyamines, putrescine (Put) and cadaverine (Cad), followed by field-amplified sample stacking (FASS) coupled with capillary electrophoresis and capacitively coupled contactless conductivity detection (FASS-CE-C4 D). Put and Cad were extracted by electrostatic attractions between the amine group of the polyamines and the citrate ligands adsorbed on the surfaces of AuNPs. AuNPs microextraction (AuNPs-ME) effectively shortened preparation time (50 min) by introducing ultrasound, and the required sample extraction volume was only 1 mL...
June 1, 2019: Talanta
Yi Zhan, Jing Tang, Di Huang, Lina Zou, Baoxian Ye
This work proposes a quenched photoelectrochemical sensing method for highly selective and sensitive detection of protein via Energy Transfer (ET) effect between the AuNPs and CdS:Mn quantum dots. This detection was performed on a sandwich-type aptamer sensing interface. Chitosan modified CdS:Mn/TiO2 /ITO electrode was used to immobilize capture DNA (S1) via -CONH- bond. In the presence of target protein, AuNPs labeled DNA (AuNPs-S2) was further bonded to the protein to fabricate sandwich sensing platform, which forced the AuNPs away from the electrode surface...
June 1, 2019: Talanta
Mengke Wang, Junyang Chen, Dandan Su, Guannan Wang, Xingguang Su
In this paper, a split aptamer based fluorescence resonance energy transfer (FRET) platform was constructed for the determination of adenosine deaminase (ADA) activity by using gold nanoclusters (AuNCs) and gold nanoparticles (AuNPs). A single adenosine triphosphate (ATP) aptamer was split into two fragments (referred to as P1 and P2). P1 was covalently attached to the AuNCs at the 5' end (P1-AuNCs), and P2 was labeled with AuNPs at the 3' end (P2-AuNPs). In the presence of ATP, ATP bound with the two fragments with high affinity to link P1-AuNCs and P2-AuNPs together, thus the fluorescence of P1-AuNCs was quenched via FRET from P1-AuNCs to P2-AuNPs...
June 1, 2019: Talanta
Chengcheng Li, Delun Chen, Yuanyuan Wang, Xiaoyong Lai, Juan Peng, Xiaohong Wang, Kexi Zhang, Yang Cao
In this paper, Au and reduced graphene oxide (rGO) were successively deposited on fluorine-doped SnO₂ transparent conductive glass (FTO, 1 × 2 cm) via a facile and one-step electrodeposition method to form a clean interface and construct a three-dimensional network structure for the simultaneous detection of nitrite and hydrogen peroxide (H₂O₂). For nitrite detection, 3D Au-rGO/FTO displayed a sensitivity of 419 μA mM-1 cm-2 and a linear range from 0.0299 to 5.74 mM, while for the detection of H₂O₂, the sensitivity was 236 μA mM-1 cm-2 and a range from 0...
March 15, 2019: Sensors
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