Adsorptive transfer stripping voltammetry

Adsorptive transfer stripping voltammetry (AdTSV) was introduced in 1986 as a new anal5 ical procedure based on the adsorptive pre-concentration of biomacromolecules on an electrode, the transfer of the adsorbed layer into a background electrolj e and subsequent voltammetric analysis [35]. The advantages of AdTSV were summarized as follows (i) the method utilizes differences in adsorbability of substances to their separation, (ii) due to their strong adsorption, analytes (oligonucleotides) can be separated from complex media, which are not suitable for voltammetric analysis of the conventional type, (iii) the interaction of biomacromolecules immobilized on the surface of the electrode with substances contained in the solution is possible, and (iv) all mentioned points can be affected by electrode potential [35]. 

Fig. 67. Adsorptive transfer stripping voltammetry on HMDE. The timing sequence accumulation time, tacc, washing time, t sh deaeration time, t, rest (equilibrating) period, t p, stripping time, tg. (During the washing period interfering substances can be removed.) Electrodes RE the reference electrode, AE the auxiliary electrode. Adapted according to [157].

Yardim Y, Levent A, Keskin E et al (2011) Voltammetric behavior of benzo(a)pyrene at boron-doped diamond electrode a study of its determination by adsorptive transfer stripping voltammetry based on the enhancement effect of anionic surfactant, sodium dodecylsulfate. Talanta 85 441 148... 

Masarik M, Kizek R, Kramer K), et al. Application of avidin-biotin technology and adsorptive transfer stripping square-wave voltammetry for detection of DNA hybridization and avidin in transgenic avidin maize. Anal. Chem., 2003 75(11) 2663-2669. 

Eojta, M., Havran, L., Fulneckova, J., Kubicarova. T. (2000). Adsorptive transfer stripping ac voltammetry of DNA complexes with intercalators. Electroanalysis 12, 926-934. 

Further improvement of the low detection limit was achieved using stripping voltammetry based on facilitated heparin adsorption and desorption [66], Stripping voltammetry yielded a detection limit of 0.13 U mL 1 in sheep blood plasma, which is lower than therapeutic heparin concentrations (>0.2 U mL-1). A linear response function in the range of 0.2-6 U mL 1 was observed. The authors also found that blood polypeptides and lipids with a mass above 25 000 significantly interfered with heparin detection, perhaps by hindrance of a charge transfer reaction at the interface. 

In addition to its quantitative aspects, adsorptive stripping voltammetry provides important contributions to our knowledge of biological compounds. In particular, considerable recent activity in our laboratory has focussed on the achievement of direct electron traiisfer for various biomacromolecules. The strategy here is to form the protein/-electrode complex , essential for a facile redox process, using an unmodified electrode. Electron-transfer rates are known to decay rapidly (exponentially) upon increasing the distance between the electrode and the redox center of the biomacromolecule. Binding of such molecules to the surface may thus be effective for electron-transfer enhancement. Other laboratories have concentrated on the use of electrode modifiers (e.g.,... 

Electrochemical measurements have been developed by using different electrochemical techniques (differential pulse voltammetry (DPV), cyclic voltametry (CV), potentiometric stripping analysis (PSA), square wave voltammetry (SWV), adsorptive stripping transfer voltammetry (ASTV), etc.). The abbreviations given in covalent attachment of DNA onto different transducers are water soluble carbodimide l-(3-dimethyaminopropyl)-3-ethyl-carbodimide (EDC), IV-hydroxysuccimide (NHS), mercaptohexanol (MCH), aminoethanethiol (AET), mercaptosilane (MSi), and N-cyclohexyl-lV -[2-(N-methylmorpholino)-ethyl]carbodimide-4-tolune sulfonate (CDS). 

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