Smartphone-based optofluidic lab-on-a-chip for detecting pathogens from blood

Area of Science:

• Biomedical Engineering
• Point-of-Care Diagnostics
• Ophthalmology

Background:

• Malaria remains a significant global health burden, necessitating rapid and accessible diagnostic tools.
• Current diagnostic methods can be time-consuming, require specialized equipment, or lack sensitivity in resource-limited settings.

Purpose of the Study:

• To develop a novel, smartphone-based detection device for infectious pathogens in human whole blood.
• To validate the device's performance using histidine-rich protein 2 (HRP-2), a specific antigen for Plasmodium falciparum (malaria).

Main Methods:

• A lab-on-a-chip device was integrated with a smartphone's LED flash (light source) and camera (detector).
• Anti-HRP-2-conjugated submicrobeads were mixed with diluted human whole blood, and Mie scatter was analyzed using blue light detection.
• A handheld attachment with optical components was designed and fabricated for smartphone integration.

Main Results:

• The device achieved a sensitive detection limit of 1 pg/mL for HRP-2 in 10% whole blood.
• The linear detection range was established from 1 pg/mL to 10 ng/mL.
• The assay demonstrated successful HRP-2 detection within approximately 10 minutes.

Conclusions:

• The developed smartphone-based system offers a sensitive and rapid method for detecting malaria antigens in blood.
• This technology holds potential for widespread application in point-of-care infectious disease diagnostics, particularly in resource-limited areas.