1A). The hanging mercury drop electrode is periodically renewed (Figure 1A1). Target molecules are adsorbed on the surface of the renewed working electrode at an open circuit (Figure 1A2). The electrode is washed with a supporting electrolyte (Figure 1A3). The electrode with the adsorbed target molecules is measured in the presence of the supporting electrolyte (Figure 1A4).Figure 1.Scheme of adsorptive transfer technique (A). Typical voltammograms of 100 nM MT (solid red line), supporting electrolyte (dotted black line) (B).Brdicka reaction of MTMT was measured by AdTS coupled with a differential pulse voltammetry (DPV) Brdicka reaction. Brdicka supporting electrolyte (1 mM Co(NH3)6Cl3 and 1 M ammonia buffer (NH3(aq) + NH4Cl, pH = 9.6) was used without surface-active agent additives. AdTS DPV Brdicka reaction parameters were as follows: an initial potential of �C0.35 V, an end potential of �C1.8 V, a modulation time of 0.057 s, a time interval of 0.2 s, a step potential of 1.05 mV, a modulation amplitude of 250 mV, Eads = 0 V. Temperature of supporting electrolyte was 4 ��C.2.3. Clinical materialHuman blood serum samples from patients with breast cancer were obtained from the Department of Clinical Biochemistry and Pathobiochemistry, FN Motol, Prague, Czech Republic. The sampled sera were immediately frozen at �C20 ��C prior to their preparation. The sample was prepared by heat treatment followed by solvent precipitation. The samples were kept at 99 ��C in a thermomixer (Eppendorf 5430, USA) for 15 min. with occasional stirring, and then cooled to 4 ��C. The denatured not homogenates were centrifuged at 4 ��C, 15,000 g for 30 min. (Eppendorf 5402, USA). Heat treatment and solvent precipitation effectively denatured and removed high molecular weight proteins from the samples [19]. MT levels in the human blood serum samples were measured by AdTS DPV Brdicka reaction.2.4. Descriptive statisticsMicrosoft Excel? (USA) was used for mathematical analyses. Results are expressed as mean �� S.D. unless noted otherwise. The detection limits (3 S/N) were calculated according to Long [20], whereas N was expressed as standard deviation of noise determined in the signal domain.3.?Results and DiscussionProteomic research demands highly sensitive analytical instruments to detect very low volumes or amounts of a biological sample. Analysis is preferably carried out on the instruments to be low cost and easy to use, and, moreover, there is great demand on miniaturization of the instruments used [21-36]. The impact of these demands is well demonstrated in the field of flow microchips technology [37-52]. Electrochemical devices, methods and approaches have a valuable contribution to this field. In particular, the introduction of adsorptive transfer technique by Prof. Palecek was a great advancement in the electroanalysis of low volume samples [52-58].3.1.