The Scattering Effect-Based Smartphone-Assisted Colorimetric Sensing for Alkaline Phosphatase Detection

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Alkaline phosphatase (ALP) is a crucial biomarker for various physiological and pathological conditions.
• Accurate and accessible quantification of ALP activity is vital for clinical diagnostics.
• Existing methods for ALP detection often require sophisticated instrumentation and trained personnel.

Purpose of the Study:

• To develop a novel, cost-effective, and label-free biosensing strategy for real-time quantification of ALP activity.
• To integrate the Tyndall effect with smartphone imaging technology for portable ALP detection.
• To establish a versatile platform for ALP detection applicable in resource-limited settings.

Main Methods:

• Utilized the Tyndall effect, where enzyme-triggered assembly of Cu-guanosine monophosphate (Cu-GMP) coordination polymers generates tunable light scattering.
• Employed smartphone imaging technology coupled with a handheld laser diode for probing Tyndall scattering.
• Investigated and optimized experimental parameters including pH, temperature, reactant concentrations, and incubation times.

Main Results:

• Demonstrated that ALP activity inversely correlates with the intensity of the Tyndall effect due to disruption of Cu-GMP polymer formation.
• Achieved a detection range of 0.375–3.75 U/mL with a limit of detection of 0.184 U/mL for ALP activity.
• Validated the method's efficacy in serum samples, showing recovery rates between 102.6% and 109.0%.

Conclusions:

• Developed a portable, instrument-free, smartphone-based colorimetric platform for ALP activity detection.
• The proposed method offers a cost-effective and label-free approach for real-time ALP quantification.
• The biosensing strategy holds significant potential for point-of-care diagnostics and applications in resource-limited environments.