Related Experiment Video
Updated: Sep 27, 2025
A Microfluidic-based Electrochemical Biochip for Label-free DNA Hybridization Analysis
Published on: September 10, 2014
A sensitive electrochemiluminescent sensor chip based on the ssDNA-Ru(II) complex and aptamer for the determination
Weiwei Luo1,2, Zhuoxin Ye1, Daqian Song1
1College of Chemistry, Jilin Province Research Center for Engineering and Technology of Spectral Analytical Instruments, Jilin University, Qianjin Street 2699, Changchun, China.
Abstract:
In this work, an electrochemiluminescence (ECL) sensor chip for sensitive detection of thrombin (TB) was prepared using a screen-printed electrode (SPE) as a working electrode and an aptamer as a specific recognition moiety. To produce an ECL sensor chip, a layer of pL-Cys was immobilized on the surface of the SPE using the cyclic voltammetry scanning method. A layer of gold nanoparticles (AuNPs) was assembled through an Au-S bond and hairpin DNA was further immobilized on the electrode surface. Ru(bpy)2 (mcpbpy)2+ , as a luminescent reagent, was covalently bound to single-stranded DNA (ssDNA) to prepare a luminescence probe ssDNA-Ru. The probe was hybridized with TB aptamer to form a capture probe. In the presence of TB, the TB aptamer in the capture probe bound to TB, causing the release of ssDNA-Ru that could bind to hairpin DNA on the electrode surface. The Ru(II) complex as a luminescent reagent was assembled onto the electrode, and pL-Cys was used as a co-reactant to enhance the ECL efficiency. The ECL signal of the sensor chip generated based on the above principles had a linear relationship with log TB concentration at the range 10 fM to1 nM, and the detection limit was 0.2 fM. Finally, TB detection using this method was verified using real blood samples. This work provides a new method using an aptamer as a foundation and SPE as a material for the detection of biological substances.
