NETRADIČNÍ FILMOVÉ ELEKTRODY VE VOLTAMETRICKÉ A AMPÉROMETRICKÉ ANALÝZE ORGANICKÝCH SLOUČENIN

Importance of the Topic

Modern analytical chemistry faces diverse challenges in detecting trace organic compounds that impact human health and the environment. Non-traditional film electrodes offer competitive alternatives to conventional mercury drop electrodes by combining miniaturization, low cost, high sensitivity, and in situ or flowing-analysis capability.

Aim and Scope of the Review

This review documents recent advances in non-traditional film electrodes—based on mercury, bismuth, antimony, and carbon conductive films—applied to voltammetric and amperometric analysis of organic compounds. It highlights their preparation, analytical performance, limitations, and practical applications.

Methodology and Instrumentation

Electrochemical techniques:

• Differential pulse voltammetry (DPV), direct current voltammetry (DCV), linear sweep voltammetry for reduction and oxidation processes.
• Amperometric flow injection analysis (FIA-AD) for continuous monitoring.

Film preparation strategies:

• Mercury film electrodes (HgFE): ex situ or in situ electrodeposition of Hg film on solid amalgam substrates (AgSAE), glassy carbon, gold, platinum, or carbon supports.
• Bismuth film electrodes (BiFE): in situ/ex situ Bi deposition from acidic Bi(III) solutions on various substrates (AgSAE, glassy carbon, Au, Cu, lead, carbon paste).
• Antimony film electrodes (SbFE): Sb deposition on glassy carbon and metallic substrates for pesticide detection.
• Carbon film electrodes: conductive composite films using natural graphite–polystyrene dispersions or screen-printed carbon inks to create renewable and modifiable electrode surfaces.

Key Findings and Discussion

Mercury film electrodes provide reproducible, submicromolar detection of nitroaromatics and other reducible organics but face environmental and anodic-window limitations. Bismuth films replicate mercury-like performance for heavy-metal and organic analytes with lower toxicity, achieving detection limits down to 10⁻⁸ M for nitrobenzimidazole when deposited on solid amalgam. Antimony films enable sensitive voltammetric detection of pesticides after solid-phase preconcentration. Carbon composite films eliminate metallic film drawbacks, support both oxidation and reduction processes, and offer simple renewal by wiping and recoating.

Benefits and Practical Applications

Non-traditional film electrodes combine:

• Low reagent consumption and minimal waste.
• Portable formats suitable for in situ and field analysis.
• High sensitivity and acceptable selectivity for biologically active organics in water.
• Rapid surface renewal and compatibility with flow systems.

Applications include trace analysis of nitrophenols, amino-nitrobenzothiazoles, pharmaceutical residues, and environmental pollutants.

Future Trends and Applications

Ongoing research will focus on surface modifications with nanomaterials (carbon nanotubes, graphene), integration into microfluidic platforms, development of multiplexed sensor arrays, and real-time environmental monitoring.

Conclusion

Non-traditional film electrodes represent versatile and environmentally friendlier tools for organic electroanalysis. They offer unique advantages over classic mercury drop electrodes, including easy film renewal, compatibility with flowing samples, and the potential for further performance enhancement through nanomaterial integration.

References

• Vyskočil V., Barek J.: Crit. Rev. Anal. Chem. 39, 173 (2009).
• Economou A., Fielden P. R.: Analyst 128, 205 (2003).
• Wang J.: Analytical Electrochemistry, 3rd ed., John Wiley & Sons, Hoboken 2006.
• Deýlová D., Yosypchuk B., Vyskočil V., Barek J.: Electroanalysis 23, 1548 (2011).
• Gajdár J., Barek J., Fischer J.: J. Electroanal. Chem. 778, 1 (2016).