Phytochelatin Modified Electrode Surface as a Sensitive Heavy- Metal Ion Biosensor

Abstract

Electrochemical biosensors have superior properties over other existing measurement systems because they can provide rapid, simple and low-cost on-field determination of many biological active species and a number of dangerous pollutants. In our work, we suggested a new heavy metal biosensor based on interaction of heavy metal ions (Cd 2+ and Zn 2+ ) with phytochelatin, which was adsorbed on the surface of the hanging mercury drop electrode, using adsorptive transfer stripping differential pulse voltammetry. In addition, we applied the suggested technique for the determination of heavy metals in a biological sample -human urine and platinum in a pharmaceutical drug. The detection limits (3 S/N) of Cd(II), Zn(II) and cis-platin were about 1.0, 13.3 and 1.9 pmole in 5 µl, respectively. On the basis of the obtained results, we propose that the suggested technique offers simple, rapid, and low-cost detection of heavy metals in environmental, biological and medical samples.

Determination of apo‐Metallothionein Using Adsorptive Transfer Stripping Technique in Connection with Differential Pulse Voltammetry

“…In addition the limit quantification of apoMT was 100 pM at t A 500 s. Moreover, apoMT has been successfully used for suggestion of EDTA MT biosensor for determination of heavy metals [65]. We found out that the suggested biosensor had similar behavior as MT and/or PC biosensor, whereas the biological part of EDTA MT biosensor enabled to reach lower detection limits about 10 -30% [34,55].…”

“…A few authors shown in Table 1 have used sodium chloride (0.5 M, pH 6.4) as a supporting electrolyte that has similar pH and ionic strength as physiological environment [34,55,56]. We again picked up the threads of a previous work and observed influence of changes of supporting electrolyte pH (0.5 M NaCl) within the range from 6.0 to 7.6 (adjusted by additions of HCl and/or NaOH) on electrochemical signal of MT.…”

Attomole voltammetric determination of metallothionein

“…Moreover, this electrochemical technique has been intensively used for the study of electrochemical metallothionein behaviour too [27][28][29]58,59]. On the base of the abovementioned results with reducing agent (TCEP), we primarily studied the effect of the TCEP on AdTS DPV signals of In our previous experiments, we proved that free ions of heavy metals are not able to be adsorbed which makes detection of the free ions impossible [52,60].…”

Detection of Cd, Pb, and Cu in non-pretreated natural waters and urine with thiol functionalized mesoporous silica and Nafion composite electrodes

“…Until the SH-SAMMS ™ -Nafion sensors, this low concentration range of metal ions in un-pretreated natural waters has been extremely difficult to detect using mercury-free electrodes. Although others have reported the detection limits of Cd, Pb, and Cu to be in low ppb levels at either mercury based electrodes or mercury-free electrodes, the values were based on 3S/N and were measured in metal spiked buffered solutions rather than in real samples [40][41][42][43]. Simultaneous detection of Cd, Pb, and Cu in 0.01 M CH 3 COONa after 3 minutes of preconcentration in a very low concentration range (0 to 10 ppb), relevant to trace level assay of the metal ions was also demonstrated in Figure 6.…”