A novel PDMS-based digital magnetofluidic platform for lab-on-a-chip applications

Abstract

Superhydrophobic gold film embedded PDMS was employed as a novel platform for digital magnetofluidics. The device performance for lab-on-a-chip applications was investigated by demonstrating four types of reactions. First, acid-based titration was introduced as a simple mixing reaction. Second, colorimetric detection of phosphate based on the molybdenum blue method was represented as a more complicated reaction. The fabricated device was able to determine the amount of phosphate in the concentration range of 10-100 ppm with %RSD of color intensity of less than 5%. Third, colorimetric detection of glucose using glucose oxidase was demonstrated as an enzymatic reaction. A linear range of 1-20 mM for determination of glucose was applied for measuring glucose in beverages with recovery percentages of glucose in the acceptable range of 89.6-106.8%. Finally, multistep analysis of C-reactive protein (CRP) based on immunomagnetic separation was successfully demonstrated on this proposed device. Therefore, the superhydrophobic gold-coated PDMS has shown its ability to be a simple platform for digital magnetofluidics for a variety of applications in the field of lab-on-a-chip technology.

Keywords: Digital magnetofluidics; Droplet actuation; Magnetic actuation; PDMS; Superhydrophobicity.