Speciation of chromium using chronoamperometric biosensors based on screen-printed electrodes

Area of Science:

• Electrochemistry
• Biosensors
• Environmental Monitoring

Background:

• Chromium contamination poses significant environmental and health risks.
• Accurate and selective detection methods for different chromium species are essential.

Purpose of the Study:

• To develop chronoamperometric biosensors for the selective detection of Cr(III) and Cr(VI).
• To enable simultaneous monitoring of both chromium species in real-world samples.

Main Methods:

• Immobilization of tyrosinase on screen-printed carbon electrodes (SPCEs) with tetrathiafulvalene (TTF) for Cr(III) detection.
• Modification of screen-printed carbon platinised electrodes (SPCPtEs) with glucose oxidase (GOx) for Cr(VI) detection.
• Development of a bipotentiostatic chronoamperometric system for simultaneous analysis.

Main Results:

• Tyrosinase-based biosensor detected Cr(III) with a limit of detection of 2.0 μM.
• GOx-based biosensor selectively detected Cr(VI) with a limit of detection of 90.5 nM, rejecting Cr(III).
• Simultaneous determination of Cr(III) and Cr(VI) was achieved in spiked tap water and tannery wastewater samples.

Conclusions:

• The developed biosensors provide a sensitive, selective, and robust method for monitoring Cr(III) and Cr(VI).
• This approach is suitable for analyzing complex environmental samples, aiding in pollution control and water quality assessment.