Biocompatible Poly(catecholamine)-Film Electrode for Potentiometric Cell Sensing

Area of Science:

• Biomaterials Science
• Electrochemistry
• Biosensing Technology

Background:

• Poly(catecholamine) (pCA) films are recognized for their biocompatibility and useful physicochemical properties, making them promising for biomaterial interfaces.
• Electrochemical methods are increasingly employed for sensitive and selective biosensing applications.

Purpose of the Study:

• To investigate the utility of poly(catecholamine) (pCA) film-coated electrodes for potentiometric biosensing.
• To evaluate the pH responsiveness and selectivity of pCA-film electrodes.
• To demonstrate the real-time monitoring of cellular activities using pCA-film electrodes.

Main Methods:

• Electropolymerization of four types of pCA films (l-dopa, dopamine, norepinephrine, epinephrine) on gold electrodes via cyclic voltammetry.
• Measurement of pH responsivity (mV/pH) across a broad pH range (1.68–10.01).
• Assessment of interference from common ions (Na+, K+, Ca2+) and proteins (albumin).
• Cultivation of HeLa cells on pCA-film electrodes to monitor changes in surface potential due to cellular activity.

Main Results:

• pCA-film electrodes exhibited significant pH responsivity (39.3–47.7 mV/pH) due to interactions with hydrogen ions.
• The pCA films effectively suppressed nonspecific signals from ions and proteins, ensuring selectivity.
• Cellular activities of HeLa cells on the electrodes caused marked changes in surface potential, correlating with alterations in local hydrogen ion concentration.
• Real-time monitoring of cellular respiration byproducts (CO2, lactic acid) was achieved.

Conclusions:

• pCA-film electrodes are suitable for developing biocompatible and pH-responsive biosensors.
• These electrodes enable selective detection of biological phenomena by monitoring changes in hydrogen ion concentration.
• The pCA-film electrode platform offers a promising approach for real-time cellular activity monitoring.