Rapid and sensitive electrochemiluminescence detection using easily fabricated sensor with an integrated...

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Electrochemical sensors offer sensitive detection methods.
• Ruthenium complexes are widely used in electrochemiluminescence (ECL) assays.
• Microfluidic devices enable miniaturized analytical systems.

Purpose of the Study:

• To investigate the ECL behavior of a ruthenium(ii) complex (Ru(bpy)3^2+) and tripropylamine (TPrA) system.
• To evaluate the performance of two-electrode systems (screen-printed and PVD electrodes) in microchips for ECL sensing.
• To demonstrate a sensitive and reliable ECL assay without a reference electrode.

Main Methods:

• Utilized screen-printed electrodes (SPE) and physical vapor deposition (PVD) electrodes integrated into microchips.
• Employed transient potential (TP) excitation within 100 ms for ECL signal generation.
• Investigated the ECL response across a concentration range of Ru(bpy)3^2+ from 1 pM to 1 μM.

Main Results:

• Achieved strong and stable ECL signals using an optimized TP on Au & Au electrode systems.
• Observed an eight-fold increase in ECL intensity on PVD chips compared to linear sweep voltammetry.
• Demonstrated a linear relationship between logarithmic ECL intensity and logarithmic Ru(bpy)3^2+ concentration (R^2 = 0.998) without a reference electrode.

Conclusions:

• The integration of a two-electrode system significantly enhances ECL sensitivity due to efficient mass transfer.
• The Ru(bpy)3^2+/TPrA system on microfluidic chips shows exceptional ECL response.
• ECL chips without a reference electrode hold great potential for rapid and sensitive multi-target detection.