(179g) Fabrication of Laser Printed Microfluidic Paper-Based Analytical Devices for Point-of-Care Applications

Fabrication of laser printed microfluidic
paper-based analytical devices for point-of-care applications

Rajesh
Ghosh^1*, Saranya Gopalakrishnan¹, Rangasamy Savitha¹,
Thiruvengadam Renganathan¹, Subramanium Pushpavanam^1*

¹Department
of Chemical Engineering,Indian Institute of Technology, Madras,
Chennai, 600036, India

*Contact:
ghoshrajesh1226@gmail.com, spush@iitm.ac.in

Microfluidic
paper-based devices (µPADs) have emerged as a versatile platform for low- cost,
portable sensing in a broad spectrum of fields such as disease diagnosis, food
safety, environmental monitoring and drug screening. However, fabrication of these
paper-based devices with selective wetting behavior i.e. hydrophobic and
hydrophilic patterns pose several challenges. Currently, a number of
fabrication strategies exist, such as, photolithography, wax printing, ink-jet
printing and etching, screen printing, plasma treatment, flexographic treatment,
chemical vapor deposition, laser treatment, hand held or automated tool etc.
Utilization of these methods involve complex fabrication steps and use of
sophisticated or rare machinery which are unavailable in most conventional
laboratory settings. Herein, we propose for the first time, a facile technique
to fabricate µPADs using a ubiquitous office laser printer. We use the inherent
hydrophobicity of the laser printer ink to create hydrophobic fluidic barriers,
without modification of factory settings of the printer. In this technique,
microfluidic channels or sensors are fabricated by just printing using the
laser printer and heating the printed substrate for generation of hydrophobic
barriers. The prepared devices are rendered selectively hydrophobic/hydrophilic
with flow of reagents and samples occurring by passive capillary action. The
proposed method circumvents the need for clean-room facility, fabrication
masks, expensive or harsh chemicals. The fabricated devices are demonstrated
for their application in sensor development by performing the detection of
nitrite and food borne pathogens. The proposed method will provide a versatile
platform for rapid prototyping of µPADs especially in resource constrained regions.

Keywords: paper-based
microfluidics, laser printing, point-of-care diagnostics