Ultrafast Detection of Arsenic Using Carbon-Fiber Microelectrodes and Fast-Scan Cyclic Voltammetry

Area of Science:

• Electrochemistry
• Environmental Science
• Analytical Chemistry

Background:

• Arsenic contamination is a global public health concern.
• Accurate detection of arsenic exposure is challenging.
• Sensitive methods are needed for arsenic monitoring.

Purpose of the Study:

• To develop a novel electrochemical sensor for As³⁺ detection.
• To optimize sensor performance using fast-scan cyclic voltammetry (FSCV) and carbon-fiber microelectrodes (CFMs).
• To evaluate sensor selectivity and sensitivity for As³⁺.

Main Methods:

• Utilized fast-scan cyclic voltammetry (FSCV) with carbon-fiber microelectrodes (CFMs).
• Conducted an in-depth pH study using tris buffer to optimize electrochemical parameters.
• Tested sensor selectivity against As⁵⁺ and common interferents.
• Employed double-bore CFMs for simultaneous detection of As³⁺ with Cu²⁺ and Cd²⁺.

Main Results:

• Achieved a limit of detection (LOD) of 0.5 μM (37.46 ppb) for As³⁺ with bare CFMs.
• Demonstrated high selectivity for As³⁺ over As⁵⁺ and interferents.
• Enhanced As³⁺ LOD to 0.2 μM (14.98 ppb) using double-bore CFMs for simultaneous detection.
• Confirmed sensor stability at physiologically relevant concentrations.

Conclusions:

• Developed the first FSCV-based sensor using CFMs for rapid and selective As³⁺ detection.
• The sensor effectively distinguishes As³⁺ from As⁵⁺ in physiologically relevant pH.
• This technology shows promise for future in vivo arsenic monitoring.