A ratiometric electrochemiluminescence sensing platform for robust ascorbic acid analysis based on a molecularly...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Developing sensitive and selective analytical methods is crucial for detecting biomolecules like ascorbic acid (AA).
• Electrochemical sensing platforms offer advantages in sensitivity and simplicity, but often face challenges with stability and selectivity.
• Ratiometric sensing strategies can enhance accuracy by providing internal calibration, compensating for environmental fluctuations.

Purpose of the Study:

• To develop a novel molecularly imprinted polymer (MIP) modified spatial-resolved "on-off" ratiometric electrochemiluminescence (ECL) sensing platform.
• To achieve highly accurate and selective detection of ascorbic acid (AA) using a closed bipolar electrode (BPE).
• To improve the repeatability and long-term stability of ECL sensing for practical applications.

Main Methods:

• Fabrication of a closed bipolar electrode (BPE) system with AA-imprinted MIP on the anode and ZnIn2S4 on the cathode.
• Utilizing Ru(bpy)32+ as the anode emitter and ZnIn2S4 as the cathode emitter for ratiometric ECL detection.
• Investigating the "on-off" ECL response mechanism triggered by AA rebinding to the MIP.
• Evaluating the sensing performance including linear range, detection limit, selectivity, repeatability, and long-term stability.

Main Results:

• The developed BPE-ECL platform demonstrated high accuracy and selectivity for AA detection.
• The ratiometric "on-off" mechanism showed a linear detection range from 50 nM to 3 μM with a low detection limit of 20 nM.
• The assay deviation was significantly reduced (15 times for repeatability, 5 times for long-term stability) compared to single-pole sensors.
• The MIP provided specific recognition of AA, enhancing the sensor's selectivity.

Conclusions:

• The novel MIP-modified BPE-ECL platform provides a reliable and stable sensing strategy for AA detection.
• The ratiometric approach effectively enhances the accuracy and stability of the ECL sensor.
• This work presents a promising strategy for designing simple, low-cost, and high-performance ECL sensing devices for practical applications.