Development of Pipetteless Paper-Based Analytical Devices with a Volume Gauge

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Paper-based analytical devices (PADs) offer a low-cost, portable platform for chemical analysis.
• Traditional PADs often require precise sample volumes, necessitating the use of micropipettes, which limits their accessibility.

Purpose of the Study:

• To develop a novel PAD design that eliminates the need for micropipettes by incorporating volume self-calibration.
• To enable volume-independent quantification using simple liquid dispensers like droppers.

Main Methods:

• A new PAD design featuring a distance-based detection channel connected to a volume-indicating storage channel was developed.
• The ratio of detection channel length to storage channel length (D/S ratio) was utilized for quantification, independent of sample volume.
• The PADs were applied to quantify iron and bovine serum albumin using specific colorimetric reagents.

Main Results:

• The D/S ratio remained constant for a given analyte concentration, irrespective of the introduced sample volume.
• Results obtained using a dropper were comparable to those using a micropipette, validating the volume-independent nature of the device.
• Good linear relationships were observed in calibration curves for iron (R²=0.989) and bovine serum albumin (R²=0.994).

Conclusions:

• The proposed PAD design facilitates accurate, volume-independent chemical analysis using simple liquid dispensers.
• This innovation enhances the accessibility and practicality of paper-based analytical devices for various applications.
• The developed PADs demonstrate reliable performance for quantifying analytes like iron and bovine serum albumin.