Ultra-Sensitivity Glucose Sensor Based on Field Emitters

A new glucose sensor based on field emitter of ZnO nanorod arrays (ZNA) was fabricated. This new type of ZNA field emitter-based sensor shows high sensitivity with experimental limit of detection of 1 nM glucose solution and a detection range from 1 nM to 50 μM in air at room temperature, which is lower than that of glucose sensors based on surface plasmon resonance spectroscopy, fluorescence signal transmission, and electrochemical signal transduction. The new glucose sensor provides a key technique for promising consuming application in biological system for detecting low levels of glucose on single cells or bacterial cultures

Kalorimetricheskoe izuchenie perekhoda spiral'-klubok v DNK pri vzaimodeistvii s ionami Cu2+

Using the method of differential scanning calorimetry, the DNA helix-coil transition was studied in solutions (10(-3) M Na+, 10(-3) M tris HCl, pH 7.0) containing divalent copper ions at relative metal ion concentrations (Mt2+/PDNA) ranging from 0.2 to 20. Dependences of the melting temperature and enthalpy on relative ion concentration were determined. An aggregation of Cu(2+) + DNA complexes in the range of average ion concentration was established. It is shown that the melting enthalpy of "units" increases with copper ion concentration. The data obtained were compared with values determined by UV-spectroscopy. Association constants for Cu2+ binding to DNA were defined by the ligand theory

SU-8 cantilevers for bio/chemical sensing; Fabrication, characterisation and development of novel read-out methods

Here, we present the activities within our research group over the last five yearswith cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interestingpolymer for fabrication of cantilevers for bio/chemical sensing due to its simple processingand low Young’s modulus. We show examples of different integrated read-out methodsand their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity tochanges in the environmental temperature and pH of the buffer solution. Moreover, weshow that the SU-8 cantilever surface can be functionalised directly with receptormolecules for analyte detection, thereby avoiding gold-thiol chemistry

Study of Ca2+, Mn2+and Cu2+ binding to DNA in solution by means of IR spectroscopy

The interaction of Cu2+, Mn2+ and Ca2+ ions with the DNA macromolecule was studied in aqueous solutions at different metal ion concentrations. All these ions interact with both the bases and the phosphate groups of DNA. Cu2+ ions alter the DNA B-conformation at [Cu2+] > 2 × 10−2M. Metal ions binding to DNA induce DNA compactisation. The highly positive cooperativity of this process was shown. The binding constants and parameters of cooperativity of the metal ions binding to DNA were estimated

Studies of Formation of Bivalent Copper Complexes with Native and Denatured DNA

ABSTRACT The formation of Cu 2+ complexes with native and denatured DNA is studied by the methods of differential UV spectroscopy, CD spectroscopy, and viscometry. On ion binding to the bases of native DNA the latter transforms into a new conformation. This transition is accompanied with a sharp increase in UV absorption and a decrease in the intrinsic viscosity though the high degree of helicity persists. Possible sites of Cu 2÷ ion binding on DNA of various conformations are found along with corresponding constants of complex formation

Vibrational spectroscopic studies of the divalent metal ion effect on DNA structural transitions

Raman spectroscopy is used to study DNA complexes with Cu2+, Mn2+ and Ca2+ ions in 0.001 M NaCl, pH 7.0. The changes observed in the spectra permit us to conclude that all the ions interact both with the DNA phosphate groups and with the nucleic bases, changing the DNA structure. Ca2+ and Mn2+ ions bind to N7 of guanine and adenine only, but Cu2+ ions can probably bind to N7, O6 of guanine and N3 of cytosine as well. The latter type of binding occurs as the base is turning around the glycoside bonds and a G-C pair transition from anti to syn conformation takes place. Besides, at high concentrations of Ca2+ ions a partial B-A transition takes place in DNA