Nucleotide sensors

The interaction of borate and boronic acid with a number of ribose-containing nucleotides and cofactors such as NAD , NADH, adenosine triphosphate (ATP) and adenosine monophosphate (AMP) have been 

BORONIC ACID SUBSTITUTED SELF-DOPED POLYANILINE 

Based on the B NMR results, upon complexation with nucleotides, the nature of the boronate esters responsible for self-doping of PABA 

20mM NADH (a) and NAD+ (b) at pH 7.4PBS. (Reprinted with permission from Chemistry of Materials, 17, 2918. Copyright (2005) American Chemical Society.) 

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See also DNA Sequencing. Enzymes Enzyme-Based Electrodes. Forensic Sciences Blood Analysis. Immunoassays, Techniques Enzyme Immunoassays. Microelectrodes. Polarography Techniques Organic Applications. Purines, Pyrimidines, and Nucleotides. Sensors Chemically Modified Electrodes. Voltammetry Organic Compounds. 

See also Electrophoresis Two-Dimensional Gels Nucleic Acids. Enzymes Enzyme-Based Assays. Flow Injection Analysis Principles. Fluorescence Quantitative Analysis. Lab-on-a-Chip Technologies. Mass Spectrometry Matrix-Assisted Laser Desorption/loniza-tion Time-of-Flight. Microelectrodes. Microscopy Overview. pH. Process Analysis Overview Chromatography Electroanalytical Techniques Sensors Acoustic Emission Maintenance, Reliability, and Training. Proteins Overview. Proteomics. Purines, Pyrimidines, and Nucleotides. Sensors Oven/iew. Spectrophotometry Overview. 

Zhang P, Rogelj S, Nguyen K, Wheeler D (2006) Design of a highly sensitive and specific nucleotide sensor based on photon upconverting particles. J Am Chem Soc 128 12410-12411... 

Figure 11.39 summarizes the reactions taking place in this amperometric sensor. FAD is the oxidized form of flavin adenine nucleotide (the active site of the enzyme glucose oxidase), and FAD1T2 is the active site s reduced form. Note that O2 serves as a mediator, carrying electrons to the electrode. Other mediators, such as Fe(CN)6 , can be used in place of O2. 

The design of fluorescent sensors is of major importance because of the high demand in analytical chemistry, clinical biochemistry, medicine, the environment, etc. Numerous chemical and biochemical analytes can be detected by fluorescence methods cations (H+, Li+, Na+, K+, Ca2+, Mg2+, Zn2+, Pb2+, Al3+, Cd2+, etc.), anions (halide ions, citrates, carboxylates, phosphates, ATP, etc.), neutral molecules (sugars, e.g. glucose, etc.) and gases (O2, CO2, NO, etc.). There is already a wide choice of fluorescent molecular sensors for particular applications and many of them are commercially available. However, there is still a need for sensors with improved selectivity and minimum perturbation of the microenvironment to be probed. Moreover, there is the potential for progress in the development of fluorescent sensors for biochemical analytes (amino acids, coenzymes, carbohydrates, nucleosides, nucleotides, etc.). 

PNA strand, resulting in an increase of the electrochemical signal (SWV peak current) as a result of probe-target hybridization. The PNA-functionalized conductive polymer sensor allowed for a detection limit of approximately 10 nM, and the feasibility for single-nucleotide mismatch detection was also demonstrated. 

Cywinski P (2006) Molecular and polymeric fluorescent pyrazolequinoline sensors for nucleotides. PhD Dissertation, Technical University of Lodz... 

Yamana et al. [67] used bis-pyrene-labeled DNA aptamer for detection of ATP. The pyrene excimer was incorporated into several nucleotide positions. Addition of ATP resulted in an increase in fluorescence only for aptamers labeled by fluorescence probe between residues that were responsible for ATP binding. Using this sensor it was possible to detect ATP with mmol/L sensitivity. 

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