Bioresponsive Release and Multiple Signal Amplification Induce a Strong Signal-On Mode for Hydrocortisone
Ziqiu Huang1, Lu Zhao1, Xianzhen Song1
1Key Laboratory of Optic-Electric Sensing and Analytical Chemistry for Life Science, Ministry of Education, Shandong Key Laboratory of Biochemical Analysis, Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Analytical Chemistry
|April 30, 2026
Summary
This study presents a novel electrochemiluminescence (ECL) sensor for highly sensitive hydrocortisone (HC) detection. The innovative design significantly enhances signal amplification, reducing false negatives and enabling ultrasensitive environmental monitoring.
Area of Science:
- Analytical Chemistry
- Biosensing
- Materials Science
Background:
- Enhancing electrochemiluminescence (ECL) sensor sensitivity is crucial for minimizing false-negative results in diagnostics and environmental monitoring.
- A pronounced signal change upon target detection is key to achieving high sensitivity in biosensing applications.
Purpose of the Study:
- To develop a novel competitive immunoreaction-triggered release strategy for ultrasensitive detection of hydrocortisone (HC).
- To construct an ECL sensor with enhanced signal amplification for improved sensitivity and reduced false-negative risk.
Main Methods:
- A competitive assay utilizing hydrocortisone (HC), antibody, and antigen was designed.
- Copper sulfide (Cu2S) snowflakes were functionalized with antibodies and ssDNA 1 (S1).
- Carbon quantum dots (C QDs) encapsulated in mesoporous silica spheres (MSS) were employed as luminophores, with pores blocked by Ag nanoparticles (NPs)-ssDNA 2 (S2)-antigen complexes.
Main Results:
- Antigen-antibody recognition triggered the release of C QDs, initiating a signal-on mode.
- Hybridization of S1 and S2 introduced Ag NPs, further amplifying the ECL signal by promoting the conversion of S2O8(2-) to SO4(•-).
- The sensor demonstrated excellent analytical performance with a wide dynamic range (100 fg/mL to 1 μg/mL) and a low limit of detection (LOD) of 25.3 fg/mL.
Conclusions:
- The developed sensor effectively utilizes a signal-on mode with multiple amplification strategies for enhanced sensitivity.
- This approach offers a promising new direction for the ultrasensitive environmental monitoring of hydrocortisone.
