Sensitive acid phosphatase assay based on light-activated specific oxidase mimic activity

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Acid phosphatase (ACP) is a crucial biomarker for diagnosing various diseases.
• Developing simple, sensitive, and real-time quantitative sensors for ACP remains a significant challenge in clinical diagnostics.

Purpose of the Study:

• To develop a sensitive colorimetric sensing strategy for ACP detection.
• To utilize the light-activated oxidase mimic property of carbon dots (CDs) for ACP quantification.

Main Methods:

• Synthesized carbon dots (CDs) exhibiting intrinsic light-activated oxidase mimic activity.
• Utilized the suppression of this activity by ascorbic acid (AA), a product of ACP-mediated hydrolysis of 2-phospho-L-ascorbic acid trisodium (AAP), for sensing.
• Employed ultraviolet light stimulation and colorimetric readout for ACP detection.

Main Results:

• Developed a facile and sensitive colorimetric method for ACP detection with a linear range of 0.1-5.5 U/L and a detection limit of 0.056 U/L.
• Demonstrated that the light-activated nanozyme's catalytic activity can be precisely controlled by light, enhancing assay accuracy.
• Successfully applied the sensing system to analyze ACP in diluted fetal bovine serum and urine samples, with results readable by naked eye or smartphone.

Conclusions:

• The developed light-activated carbon dot-based sensor provides a sensitive and controllable method for ACP detection.
• This approach offers advantages over conventional nanozyme-based assays due to its ease of regulation and direct readout.
• The sensing system shows significant promise for clinical analysis and point-of-care (POC) biosensor platforms.