Electrochemical and Catalytic Properties of the Adenine Coenzymes FAD and Coenzyme A on Pyrolytic Graphite Electrodes

Electroanalysis of NADH Using Conducting and Redox Active Polymer/Carbon Nanotubes Modified Electrodes-A Review

Past few decades, conducting and redox active polymers play a critical role in the development of transducers for biosensing. It has been evidenced by increasing numerous reports on conducting and redox active polymers incorporated electrodes for assay of biomolcules. This review highlights the potential uses of electrogenerated polymer modified electrodes and polymer/carbon nanotubes composite modified electrodes for electroanalysis of reduced form of nicotinamide adenine dinuceltoide (NADH). In addition, carbon electrodes modified with organic and inorganic materials as modifier have been discussed in detail for the quantification of NADH based on mediator or mediator-less methods.

A new spectrofluorometric probe for the determination of trace amounts of CoA in injection, human serum and pig livers

A new spectrofluorometric method has been developed for the determination of trace amounts of coenzyme A (CoA). Using europium (Eu3+)-tetracycline (TC) complex as a fluorescent probe in the buffer solution of pH 6.80, CoA could remarkably enhance the fluorescence intensity of the Eu3+-TC complex at lambda = 612 nm after adding H(5)IO(6) and the enhanced fluorescence intensity is in proportion to the concentration of CoA. Optimum conditions for the determination of CoA were also investigated. The dynamic range for the determination of CoA is 6.08 x 10(-8) - 1.84 x 10(-5) mol L(-1) with detection limit of 4.62 x 10(-8) mol L(-1). This method is simple, practical and relatively free of interference from coexisting substances and can be successfully applied to determination of CoA in injection, human serum and pig liver samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu3+-TC system and the CoA-Eu3+-TC system have been also discussed.

Spectrofluorimetric determination of trace amounts of coenzyme A using a terbium ion-ciprofloxacin complex probe in the presence of periodic acid

A new spectrofluorimetric method was developed for the determination of trace amounts of coenzyme A (CoA). In the presence of periodic acid (H5IO6), CoA can remarkably enhance the fluorescence intensity of the Tb3+-ciprofloxacin (CIP) complex at 545 nm in a buffer solution at pH 5.4; the enhanced fluorescence intensity of the Tb3+ ion is proportional to the concentration of CoA. The optimal conditions for the determination of CoA were also investigated. The linear range and the detection limit for the determination of CoA were 6.08x10(-6)-1.64x10(-5) and 2.1x10(-8) mol L-1, respectively. This method is simple, practical and relatively free of interference from coexisting substances, and can be successfully applied to assess CoA in injection and biological samples. Moreover, the enhancement mechanism of the fluorescence intensity of the CoA-Tb3+-CIP system in the presence of H5IO6 is also discussed.