In Situ Fluorogenic Reaction Generated via Ascorbic Acid for the Construction of Universal Sensing Platform.

Area of Science:

• Analytical Chemistry
• Biochemistry
• Materials Science

Background:

• Fluorescent probes offer sensitive detection methods.
• Enzyme-based assays are crucial for diagnostics.
• Terephthalic acid (PTA) and ascorbic acid (AA) exhibit a temperature-dependent fluorescent reaction.

Purpose of the Study:

• To investigate the mechanism of a novel fluorescent emission reaction between PTA and AA.
• To develop a sensitive and selective platform for alkaline phosphatase (ALP) detection.
• To establish an ALP-based enzyme-linked immunoassay (ELISA) for cancer biomarker detection.

Main Methods:

• Detailed characterization of the PTA-AA fluorescent reaction mechanism using electron paramagnetic resonance and mass spectrometry.
• Integration of ALP-triggered conversion of l-ascorbic acid 2-phosphate trisodium salt to AA into the fluorescent system.
• Fabrication and testing of an ALP-based ELISA for carcinoembryonic antigen (CEA) detection.

Main Results:

• A highly fluorescent emission reaction between PTA and AA was revealed, controllable by temperature.
• The developed platform demonstrated sensitive and selective detection of ALP activity.
• The ALP-based ELISA achieved a linear correlation between fluorescence intensity and CEA concentration (0.25-30 ng/mL) with a detection limit of 0.08 ng/mL.

Conclusions:

• A facile and direct fluorescent assay based on the PTA-AA reaction was established, avoiding nanomaterial catalysis.
• The system provides a sensitive and universal platform for ALP activity monitoring.
• This approach offers a promising strategy for early clinical diagnosis of ALP-related conditions and cancer biomarkers like CEA.