Application of cold plasma corona discharge in preparation of laccase-based biosensors for dopamine determination

Abstract

Laccase-based biosensors were successfully prepared using innovative, cheap, one-step Soft Plasma Polymerization technique by deposition of a bio-recognition layer on glassy carbon electrode and MWCNT (Multi-walled Carbon Nanotubes)-modified glassy carbon electrode. The Soft Plasma Polymerization technique is based on corona discharge of cold atmospheric plasma with close to room temperature. The presented work includes study of biosensor working conditions, optimization of the voltage value applied for corona discharge generation as well as applicability and interference studies for dopamine determination. The biosensor constructed under optimal conditions (corona discharge generated at a voltage of 3 kV and in 30 s time deposition, helium flow rate 10 L/min, laccase solution flow rate 200 μL/min) has two linear ranges from 0.1 μmol/dm³ to 10 μmol/dm³ and from 10 μmol/dm³ to 50 μmol/dm³ with dopamine detection sensitivities of 3.63 μA*dm³/μmol and 1.33 μA*dm³/μmol. Application of the MWCNT interlayer allows the dopamine detection sensitivity to be significantly increased to 22.35 μA* dm³/μmol for a linear range from 0.1 μmol/dm³ to 6 μmol/dm³. Additionally, the studied biosensors have stable and anti-interference ability. Both biosensors were successfully applied for dopamine determination in pharmaceutical preparation.

Keywords: Cold plasma; Dopamine; Laccase; Multi-walled carbon nanotubes; Plasma polymerization.