Graphene oxide and gold nanoparticle based dual platform with short DNA probe for the PCR free DNA biosensing using Surface Enhanced Raman Scattering (SERS)

Surface-enhanced Raman scattering (SERS) based DNA biosensors have considered as excellent, fast and ultrasensitive sensing technique which relies on the fingerprinting ability to produce molecule specific distinct spectra. Unlike conventional fluorescence based strategies SERS provides narrow spectral bandwidths, fluorescence quenching and multiplexing ability, and fitting attribute with short length probe DNA sequences. Herein, we report a novel and PCR free SERS based DNA detection strategy involving dual platforms and short DNA probes for the detection of endangered species, Malayan box turtle (MBT) (Cuora amboinensis). In this biosensing feature, the detection is based on the covalent linking of the two platforms involving graphene oxide-gold nanoparticles (GO-AuNPs) functionalized with capture probe 1 and gold nanoparticles (AuNPs) modified with capture probe 2 and Raman dye (Cy3) via hybridization with the corresponding target sequences. Coupling of the two platforms generates locally enhanced electromagnetic field ‘hot spot’, formed at the junctions and interstitial crevices of the nanostructures and consequently provide significant amplification of the SERS signal. Therefore, employing the two SERS active substrates and short-length probe DNA sequences, we have managed to improve the sensitivity of the biosensors to achieve a lowest limit of detection (LOD) as low as 10 fM. Furthermore, the fabricated biosensor exhibited sensitivity even for single nucleotide base-mismatch in the target DNA as well as showed excellent performance to discriminate closely related six non-target DNA sequences. Although the developed SERS biosensor would be an attractive platform for the authentication of MBT from diverse samples including forensic and/or archaeological specimens, it could have universal application for detecting gene specific biomarkers for many diseases including cancer

2- 4-Acetyl-5-(biphenyl-4-yl)-4,5-dihydro-1,3,4-oxadiazol-2-yl phenyl acetate

In the title molecule, C(24)H(20)N(2)O(4), the five-membered oxadiazole ring is nearly planar (r.m.s. deviation = 0.053 angstrom) and the phenyl ring of the biphenyl unit attached to it forms a dihedral angle of 73.2 (1)degrees; the other phenyl ring is close to coplanar with the oxadiazole ring [dihedral angle = 6.2 (2)degrees]

Biphenyl-4-carbaldehyde azine

The complete molecule of the title compound, C(26)H(20)N(2), is generated by crystallographic inversion symmetry. The terminal phenyl ring is twisted by 19.2 (1)degrees with respect to the adjacent phenylene ring

N-Acetyl-2-hydroxy-N'-[methoxy(1-methylindol-2-yl)methyl]benzohydrazide

In the crystal structure of the title Schiff-base, C(20)H(21)N(3)O(4), the amino group forms an N-H⋯O hydrogen bond to the acetyl group of an adjacent mol-ecule, forming a zigzag chain. The 2-hydr-oxy group is inter-nally hydrogen bonded to the amido group though an O-H⋯O hydrogen bond

Di-n-butyl-ammonium 2-(3,5-di-tert-butyl-4-hydroxy-benzyl-sulfan-yl)nicotinate

The asymmetric unit of the title compound, C(8)H(20)N(+)·C(21)H(26)NO(3)S(-), contains two indpendent ion pairs which are disposed about a psuedo-inversion center, generating an ammonium-carboxylate N-H⋯O hydrogen-bonded four-component cluster. In the crystal structure, adjacent clusters are linked by hydr-oxy-carboxylate O-H⋯O hydrogen bonds, forming a chain

Synthesis, magnetic and spectroscopic studies of Ni(Ii), Cu(Ii), Zn(Ii) and Cd(Ii) complexes of a newly Schiff Base derived from 5-Bromo-2-Hydroxybezylidene)-3,4,5-Trihydroxybenzohydrazide)

A new hydrazide Shiff base ligand GHL1 (5-bromo-2-hydroxybezylidene)-3,4,5-trihydroxybenzohydrazide) was prepared by refluxing of trihydroxybenzhydrazide with an ethanolic of 5-bromo-2-hydroxybenzaldehyde. The ligand reacted with Ni(II), Cu(II), Zn(II) and Cd(II) (acetate salts). All the complexes were characterized by elemental analysis, molar conductivity, TGA, UV-Vis and FT-IR spectral studies. All the complexes have octahedral geometry except Ni(II) complex which has tetrahedral geometry

Preparation and spectroscopic investigation of newly schiff Base of 5-chloro-2-hydroxybenzylidene)-3,4,5-trihydroxybenzohydrazone with some metal ions

An ethanolic solution of metal salts was added slowly to an ethanolic solution of 5-chloro-2hydroxybenzylidene)-3,4,5-trihydroxybenzohydrazone with few drops of Methylamin to give complexes with the general formula [M(GHL2) 2]. 2H 2O, [Cu 2(GHL2) 2]. 4H 2O and [Cd(GHL2)(CH 3COO) 2]. 2H 2O where M is Ni(II) and Zn(II), GHL2 is 5-chloro-2-hydroxybenzylidene)-3,4,5- trihydroxybenzohydrazone. The resulting complexes were characterized by elemental analysis, magnetic measurements and spectral studies. The Schiff base GHL2 ligand acts as tridentate ligand was coordinated with the metal ions through O, N, O except with Cd(II) as the ligand behaves as bidentate ligand coordinated with Cd(II) ion through O, N atoms. However, [M(GHL2) 2J. 2H 2O and [Cd(GHL2)(CH,COO) 2]. 2H 2O were proposed to possess Octahedral geometry while [Cu 2(GHL2) 2]. 4H 2O was proposed to possess tetrahedral geometry

Antioxidant, cytotoxic activities, and structure-activity relationship of gallic acid-based indole derivatives

A new series of gallic hydrazones containing an indole moiety was synthesized through the reaction of gallic hydrazide and different indole carboxaldehydes. Their antioxidant activities were determined on DPPH radical scavenging and inhibition of lipid peroxidation. The in-vitro cytotoxic activities of the compounds were evaluated against HCT-116 (human colon cancer cell line) and MCF-7 (estrogen-dependent human breast cancer cell line) by the MTT method. An attempt to correlate the biological results with their structural characteristics has been done. A limited positive structure activity relationship was found between cytotoxic and antioxidant activities

The Influence of Ziegler-Natta and Metallocene Catalysts on Polyolefin Structure, Properties, and Processing Ability

50 years ago, Karl Ziegler and Giulio Natta were awarded the Nobel Prize for their discovery of the catalytic polymerization of ethylene and propylene using titanium compounds and aluminum-alkyls as co-catalysts. Polyolefins have grown to become one of the biggest of all produced polymers. New metallocene/methylaluminoxane (MAO) catalysts open the possibility to synthesize polymers with highly defined microstructure, tacticity, and steroregularity, as well as long-chain branched, or blocky copolymers with excellent properties. This improvement in polymerization is possible due to the single active sites available on the metallocene catalysts in contrast to their traditional counterparts. Moreover, these catalysts, half titanocenes/MAO, zirconocenes, and other single site catalysts can control various important parameters, such as co-monomer distribution, molecular weight, molecular weight distribution, molecular architecture, stereo-specificity, degree of linearity, and branching of the polymer. However, in most cases research in this area has reduced academia as olefin polymerization has seen significant advancements in the industries. Therefore, this paper aims to further motivate interest in polyolefin research in academia by highlighting promising and open areas for the future.Process and EnergyMechanical, Maritime and Materials Engineerin