A dual-mode nano-microelectrode for PTH detection at the single-cell level

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Cell Biology

Background:

• Parathyroid hormone (PTH) is crucial for calcium-phosphate balance and bone health.
• Aberrant PTH levels are linked to chronic kidney disease and cancers.
• Existing PTH detection methods lack single-cell resolution and dual-signal capabilities.

Purpose of the Study:

• To design and validate a dual-signal nano-microelectrode for sensitive, single-cell PTH detection.
• To enable label-free, rapid, and specific intracellular PTH analysis.
• To investigate PTH regulation in response to extracellular calcium.

Main Methods:

• Fabrication of a nano-microelectrode by modifying gold nanopipettes with ferrocene-labeled DNA and 6-mercaptohexanol.
• Utilizing square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) for PTH detection.
• Employing 3D micro-manipulation for minimally invasive single-cell penetration and analysis.

Main Results:

• The sensor exhibited linear responses for PTH detection within specific concentration ranges (SWV: 1-500 pg mL⁻¹, EIS: 1-1000 pg mL⁻¹).
• Demonstrated high selectivity against intracellular interferents and good electrode consistency.
• Successfully detected intracellular PTH changes in single cells, correlating with extracellular calcium levels.

Conclusions:

• The developed dual-signal nano-microelectrode offers a new tool for rapid, low-cost, label-free, and highly specific single-cell PTH analysis.
• This technology advances the study of PTH's role in cellular processes and disease.
• The findings align with known calcium-sensing receptor regulatory mechanisms.