Direct-write laser techniques for the manufacture of multiplexed paper-based diagnostic sensors

The ever-present need for affordable and reliable devices for health monitoring has led to a significant growth over the past few years in the development and applications of paper-based point-of-care diagnostics that operate with minimal reagent volumes, are portable and need no special training or equipment for their use.

We present here our work on the fabrication of multiplexed paper-based diagnostic sensors for the detection of glucose and bovine serum albumin (BSA) using lasers-based methods. Our use of lasers for the fabrication of the devices is justified by the versatility, speed of production, and cost, all of which are of critical importance for mass-market applications. A laser direct-write process, Laser-Induced Forward Transfer (LIFT), was used to print the reagents and biological molecules on paper substrates that facilitate the sensing of the specific analytes. A second laser-based process was also implemented to create hydrophobic walls and barriers in paper and membrane substrates, which define the wells and channels that can guide biological and chemical solutions through the paper devices. A pulsed KrF excimer laser operating at 248 nm was used for LIFT and a continuous wave laser at 405 nm was used for patterning of the paper. The small dimensions of the structures produced (~100 µm) and the precise and low-volume (nl) deposition of materials by these processes enable the miniaturisation of these devices ensuring the minimal use of reagents. We have quantified the speed and cost of our laser-based methods and believe they can be up-scaled for mass production.

Katis, I.N.

f92dfb8f-610d-4877-83f6-fd26a571df12

He, P.J.W.

2e303166-6aa5-4a09-b22e-440d96a54a9f

Eason, R.W.

e38684c3-d18c-41b9-a4aa-def67283b020

Sones, C.L.

9de9d8ee-d394-46a5-80b7-e341c0eed0a8

February 2015