No-cost ballpoint pen dispenser for lateral flow assays

Area of Science:

• Biomedical Engineering
• Assay Development
• Point-of-Care Diagnostics

Background:

• Lateral flow assays (LFAs) are crucial for rapid diagnostics.
• Precise antibody deposition is key for LFA performance.
• Current methods often require specialized equipment.

Purpose of the Study:

• To develop an affordable, user-friendly dispenser for antibody line generation in LFAs.
• To enable freehand drawing of test and control lines with controlled widths.
• To validate the dispenser's performance using a model antigen.

Main Methods:

• Utilized a modified empty ballpoint pen as a human-powered dispenser.
• Employed Naphthol green B stain for antibody labeling and trace certification.
• Imprinted antibodies onto nitrocellulose membranes for lateral flow assay fabrication.
• Tested the dispenser's capability using human chorionic gonadotropin (HCG) as a model antigen.

Main Results:

• The pen dispenser successfully deposited antibodies in narrow zones (0.15–1.00 mm width).
• Antibody imprinting did not compromise nitrocellulose membrane microstructure or chromatographic function.
• The developed lateral flow assay detected HCG at concentrations as low as 0.1 μg/mL.
• Assay sensitivity was comparable to tests using conventional benchtop dispensers.

Conclusions:

• A novel, no-cost, human-powered pen dispenser offers a viable alternative for LFA fabrication.
• The dispenser facilitates precise antibody line generation, crucial for diagnostic test development.
• This innovation has the potential to improve accessibility and reduce costs in point-of-care diagnostics.