Aptamer Regulated NIR Carbon Dot/AuNP Fluorescence Sensing Platform for Selective Sarcosine Detection

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Sarcosine (SA) is a potential prostate cancer biomarker.
• Accurate detection of sarcosine is crucial for early diagnosis and treatment monitoring.
• Existing detection methods may lack sensitivity, selectivity, or require complex procedures.

Purpose of the Study:

• To develop a sensitive and selective near-infrared (NIR) fluorescence sensing platform for sarcosine detection.
• To utilize NIR carbon dots (CDs), gold nanoparticles (AuNPs), and sarcosine-specific aptamers (SA-Apt) for this purpose.
• To establish an aptamer-regulated inner filter effect (IFE) based sensing mechanism.

Main Methods:

• Synthesized nitrogen- and sulfur-co-doped NIR-CDs using a solvothermal method.
• Prepared AuNPs via a citrate-reduction approach.
• Developed a sensing mechanism based on SA-Apt binding to SA, leading to AuNP aggregation and NIR-CD fluorescence quenching via IFE.

Main Results:

• The NIR-CDs/AuNPs/SA-Apt platform showed a linear response to sarcosine from 1-15 µM (R²=0.996).
• Achieved a limit of detection of 0.32 µM (S/N=3) with high selectivity and reproducibility.
• Demonstrated stable NIR fluorescence performance and effective sarcosine quantification.

Conclusions:

• The developed aptamer-regulated IFE sensing platform provides a robust, non-enzymatic strategy for sensitive and selective sarcosine detection.
• This approach holds promise for the early diagnosis of prostate cancer.
• Integration of NIR-CDs and AuNPs enhances sensing performance, offering a valuable tool in biomarker detection.