Single-atom Ni-N₄ provides a robust cellular NO sensor

Area of Science:

• Electrochemistry
• Materials Science
• Biomedical Engineering

Background:

• Nitric oxide (NO) plays crucial roles in physiological and pathological processes.
• Accurate monitoring of cellular NO levels requires sensitive, biocompatible sensors with transient recording capabilities.
• Existing sensors often lack the necessary performance for real-time cellular NO detection.

Purpose of the Study:

• To develop a novel single-atom catalyst (SAC)-based electrochemical sensor for detecting nitric oxide (NO) in live cellular environments.
• To evaluate the sensor's performance, including sensitivity, biocompatibility, and transient recording ability.
• To demonstrate the sensor's utility in real-time NO monitoring under cellular stimulation.

Main Methods:

• Fabrication of a sensor using nickel single atoms anchored on N-doped hollow carbon spheres (Ni SACs/N-C).
• Electrochemical characterization of Ni SACs/N-C for NO oxidation catalysis.
• Testing the sensor's performance in live cellular environments, including response to drug and stretch stimulation.
• Assessing sensor biocompatibility and sensitivity at the nanomolar level.

Main Results:

• Ni SACs/N-C exhibited superior electrocatalytic performance for NO oxidation compared to conventional Ni nanomaterials due to reduced activation energy.
• The developed sensor demonstrated high biocompatibility and low nanomolar sensitivity.
• Real-time monitoring of NO release from cells was successfully achieved upon drug and stretch stimulation.
• The flexible and stretchable nature of the sensor enhanced its applicability in dynamic cellular conditions.

Conclusions:

• Single-atom catalysts (SACs) provide a promising platform for developing highly efficient electrochemical sensors.
• The Ni SACs/N-C sensor enables sensitive and real-time detection of NO in live cells.
• This technology offers a valuable tool for investigating NO-related biological processes and cellular responses.