Design and Fabrication of Capillary-Driven Flow Device for Point-Of-Care Diagnostics

Abstract

Point-of-care (POC) diagnostics enables the diagnosis and monitoring of patients from the clinic or their home. Ideally, POC devices should be compact, portable and operatable without the requirement of expertise or complex fluid mechanical controls. This paper showcases a chip-and-dip device, which works on the principle of capillary-driven flow microfluidics and allows analytes' detection by multiple microchannels in a single microchip via smartphone imaging. The chip-and-dip device, fabricated with inexpensive materials, works by simply dipping the reagents-coated microchip consisting of microchannels into a fluidic sample. The sample is loaded into the microchannels via capillary action and reacts with the reagents to produce a colourimetric signal. Unlike dipstick tests, this device allows the loading of bacterial/pathogenic samples for antimicrobial testing. A single device can be coated with multiple reagents, and more analytes can be detected in one sample. This platform could be used for a wide variety of assays. Here, we show the design, fabrication and working principle of the chip-and-dip flow device along with a specific application consisting in the determination of β-lactamase activity and cortisol. The simplicity, robustness and multiplexing capability of the chip-and-dip device will allow it to be used for POC diagnostics.

Capillary-Driven Flow Microfluidics Combined with Smartphone Detection: An Emerging Tool for Point-of-Care Diagnostics

“…Multiple FEP microcapillaries were used to identify AST profiles, which were found to be in comparison with standard technologies and within the clinical range of the patient urine (103–108 CFU/mL). Recently, our group developed a Chip-and-Dip device fabricated with PMMA, and the sample loading was realized by simply dipping the chip into the sample solutions ( Figure 3 c) [ 66 ]. By coating microchannels with nitrocefin, it enabled beta-lactamase activity to be monitored in the microchannels.…”

“…Therefore, we have proposed that smartphone-based capillary flow device, which would be an ideal option for rapid image capturing and data analysis ( Figure 4 a,b). Several studies using smartphone-based imaging in capillary flow devices have been performed, such as the quantitation of the prostate-specific antigen in FEP microcapillaries, beta-lactamase activity in microchannels and anemia diagnosis [ 43 , 66 , 83 ]. Plevnial et al [ 83 ] developed a standalone POC diagnostics system via integration of a 3D-printed capillary flow device with smartphone imaging, as shown in Figure 4 b.…”

“…Reproduced with permission from [ 16 ]; ( c ) Chip-and-dip capillary flow device fabrication and working schematic for beta-lactamase activity testing in microchannels ( a , b ). Reproduced with permission from [ 66 ].…”

A Smartphone-Fluidic Digital Imaging Analysis System for Pancreatic Islet Mass Quantification

“…Such microfluidic devices possess many advantages over more established in vitro assays, including reduced reagent consumption requirements, low cost of manufacturing and maintenance, multiplexing capabilities, increased assay sensitivity, increased accuracy, and higher spatiotemporal resolution ( Kappler et al, 2004 ; Adewola et al, 2010 ; Nourmohammadzadeh et al, 2016 ; Xing et al, 2016 ; Lu et al, 2018 ). An exciting development in recent years is the adaptation of smartphone technology to microfluidic platforms for point-of-care (POC) chemical and biological detection, as well as for particle counting and analysis ( Long et al, 2017 ; Huang X. et al, 2018 ; Liu et al, 2019 ; Hassan and Zhang, 2020 ).…”

Capillaric - Field Effect Transistors

“…4,5 These advantages have led to capillarics being used for a wealth of new applications in recent years, in particular in the biosensing space. [6][7][8][9][10][11][12][13][14][15][16][17][18] One fundamental requirement for the fully autonomous operation of capillaric circuits continues to be the availability of basic valving operations that do not need any external power source. Until recently, this was limited to two-level trigger valves 1,2, 19 or externally controlled valves.…”