An inkjet printed, roll-coated digital microfluidic device for inexpensive, miniaturized diagnostic assays

Abstract

The diagnosis of infectious disease is typically carried out at the point-of-care (POC) using the lateral flow assay (LFA). While cost-effective and portable, LFAs often lack the clinical sensitivity and specificity required for accurate diagnoses. In response to this challenge, we introduce a new digital microfluidic (DMF) platform fabricated using a custom inkjet printing and roll-coating process that is scalable to mass production. The performance of the new devices is on par with that of traditional DMF devices fabricated in a cleanroom, with a materials cost for the new devices of only US $0.63 per device. To evaluate the usefulness of the new platform, we performed a 13-step rubella virus (RV) IgG immunoassay on the inkjet printed, roll-coated devices, which yielded a limit of detection of 0.02 IU mL, well below the diagnostic cut-off of 10 IU mL −1 for RV infection and immunity. We propose that this represents a breakthrough for DMF, lowering the costs to a level such that the new platforms will be an attractive alternative to LFAs for the diagnosis of infectious disease at the POC.

Application of nanodiagnostics in point-of-care tests for infectious diseases

“…Among them, lab-on-a-chip and microfluidics techniques have shown good promise for the detection of infectious diseases. 54,55 Through these techniques, multiple assays could be integrated into one single device, 56,57 resulting in a decrease in the volume of samples from infected patients, the consumption of materials, and the analysis time. These advantages of the integrated systems could greatly potentiate to build low-cost and portable devices.…”

Accessing individual 75-micron diameter nozzles of a desktop inkjet printer to dispense picoliter droplets on demand

“…In the past there have already been multiple attempts in various science disciplines to use (modied) consumer-grade desktop inkjet printers for a variety of applications. Dixon et al 10 used a consumer-grade piezoelectric printer to dispense a commercially available silver nanoparticle ink to create digital microuidic devices (DMF), for an inexpensive, miniaturised diagnostic assay. The performance of these inkjet printed devices was found to be comparable with devices fabricated using traditional clean room techniques, with a material cost of less than $1 per device, demonstrating the potential of desktop inkjet printers for this application.…”

A digital microfluidic system for serological immunoassays in remote settings

“…Both types of bottom plates (Ia,b) featured 92 roughly square interdigitated driving electrodes (2.8 mm × 2.8 mm), 10 reservoir electrodes (10 mm × 6.7 mm), and 10 dispensing electrodes (5.2 mm × 2.4 mm). For inkjet-printed bottom plates (Ia), an Epson C88+ inkjet printer (Seiko Epson Corporation) was used to deposit Metalon JS-B25P silver nanoparticle ink onto Novele IJ-220 substrates (NovaCentrix), as described previously (40). After printing, devices were diced and affixed to glass slides (S.I.…”