Silver ion-regulated reliable and rapid detection technique for alkaline phosphatase based on surface-enhanced Raman...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Accurate and rapid clinical assays are crucial for medical treatment monitoring.
• Alkaline phosphatase (ALP) is an important biomarker in various medical conditions.
• Existing detection methods may lack the desired speed, sensitivity, or reliability.

Purpose of the Study:

• To develop a novel, rapid, and highly sensitive detection technique for alkaline phosphatase (ALP) in human serum.
• To leverage the controlled "hot spot" effect in surface-enhanced Raman scattering (SERS) for enhanced detection.
• To establish a reliable point-of-care diagnostic tool for ALP monitoring.

Main Methods:

• Fabrication of a SERS substrate using functionalized gold nanoparticles (Au NPs) and p-mercaptobenzonitrile (MBN).
• Utilizing silver ions (Ag+) to mediate the controlled aggregation of Au NPs, creating "hot spots" for signal amplification.
• Employing the enzymatic reaction of ALP on 2-phospho-L-ascorbic acid trisodium salt (AAP) to trigger a decrease in Ag+ concentration, correlating with ALP levels.

Main Results:

• The SERS technique achieved highly amplified signals for MBN at 2228 cm-1 due to controlled Au NP aggregation.
• A direct correlation was established between the decrease in MBN SERS intensity and increasing ALP concentrations.
• The assay demonstrated a low limit of detection (LOD) of 1.23 pg mL-1 (0.005 U L-1) for ALP.

Conclusions:

• The developed SERS detection technique provides a rapid, reliable, and highly sensitive method for ALP detection in human serum.
• The controlled "hot spot" mechanism mediated by silver ions is effective for amplifying SERS signals.
• This technique shows significant potential as a point-of-care diagnostic tool for ALP monitoring due to its stability and efficacy.