Chemiluminescent Ion Sensing Platform Based on Ionophores

Area of Science:

• Analytical Chemistry
• Chemical Sensors
• Chemiluminescence

Background:

• Ion-selective sensors are crucial for various applications, including environmental monitoring and clinical diagnostics.
• Conventional methods often face challenges with selectivity, sensitivity, and complex sample matrices.
• Chemiluminescence offers a sensitive detection mechanism, but its integration with ion-selective platforms requires innovative approaches.

Purpose of the Study:

• To develop a versatile ionophore-based chemiluminescent platform for selective ion detection.
• To demonstrate the platform's adaptability for detecting different target ions, including monovalent and divalent cations.
• To validate the method's performance and applicability in real-world samples, such as diluted human blood serum.

Main Methods:

• Utilized an ion-exchange mechanism where target ions displace divalent organic cations (lucigenin).
• Employed ionophores (valinomycin for K+, Pb2+ ionophore for Pb2+) for selective ion recognition.
• Integrated chemiluminescence detection triggered by the reaction of lucigenin with hydrogen peroxide under alkaline conditions.
• Investigated the influence of phase ratios on detection range and compared sensitivity for monovalent and divalent ions.

Main Results:

• Achieved selective chemiluminescent detection of potassium (K+) over a wide range (10 nM to 1 M) using valinomycin.
• Demonstrated high selectivity and sensitivity for lead (Pb2+) detection (0.1 nM to 0.1 mM) by switching to a Pb2+ ionophore.
• Showcased enhanced sensitivity for divalent ions compared to conventional ion-selective optodes due to lucigenin.
• Validated the method's applicability by accurately determining K+ in diluted human blood serum samples, showing good agreement with potentiometric methods.

Conclusions:

• The ionophore-based chemiluminescent platform provides a highly selective and sensitive method for ion detection.
• The platform's versatility allows for the detection of various ions by simply changing the ionophore.
• This approach offers a promising alternative to existing ion-sensing technologies, with potential for broader applications in complex sample analysis.