Fully Automated Centrifugal Microfluidic Device for Ultrasensitive Protein Detection from Whole Blood

Abstract

Enzyme-linked immunosorbent assay (ELISA) is a promising method to detect small amount of proteins in biological samples. The devices providing a platform for reduced sample volume and assay time as well as full automation are required for potential use in point-of-care-diagnostics. Recently, we have demonstrated ultrasensitive detection of serum proteins, C-reactive protein (CRP) and cardiac troponin I (cTnI), utilizing a lab-on-a-disc composed of TiO2 nanofibrous (NF) mats. It showed a large dynamic range with femto molar (fM) detection sensitivity, from a small volume of whole blood in 30 min. The device consists of several components for blood separation, metering, mixing, and washing that are automated for improved sensitivity from low sample volumes. Here, in the video demonstration, we show the experimental protocols and know-how for the fabrication of NFs as well as the disc, their integration and the operation in the following order: processes for preparing TiO2 NF mat; transfer-printing of TiO2 NF mat onto the disc; surface modification for immune-reactions, disc assembly and operation; on-disc detection and representative results for immunoassay. Use of this device enables multiplexed analysis with minimal consumption of samples and reagents. Given the advantages, the device should find use in a wide variety of applications, and prove beneficial in facilitating the analysis of low abundant proteins.

Exodisc for Rapid, Size-Selective, and Efficient Isolation and Analysis of Nanoscale Extracellular Vesicles from Biological Samples

“…Finally, the buffer solution was completely removed, and 3,3′,5,5′-tetramethylbenzidine (TMB) solution was added (Figure A). After a 1 min of incubation, the blue-colored solution was transferred to the detection chamber, which was preloaded with a stop solution, and the OD was measured at 450 nm using a custom-built detection system …”

“…After incubation, the TMB solution was transferred to the detection chamber, where it was mixed with 50 μL of the stop solution. Solution absorbance was measured at 450 nm using a custom built detection system …”

ImmunoDisk—A Fully Automated Bead-Based Immunoassay Cartridge with All Reagents Pre-Stored

“…Pre-analytic protocols such as blood–plasma separation [ 15 ] and pre-treatment of whole saliva [ 16 ] can be easily implemented. These are some reasons why many different centrifugal system-based immunoassay solutions have been shown, using different assay methods and with different applications [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ].…”

“…One main structural feature of most of the demonstrated immunoassays based on centrifugal systems is that they use magnetic or fluorescent micro/nanoparticles (in fact, only a few systems do not [ 18 , 22 , 26 , 28 , 39 ]). This is not surprising, as particles have been proven advantageous not only in miniaturized systems.…”

Hypergravity-induced multicellular spheroid generation with different morphological patterns precisely controlled on a centrifugal microfluidic platform

“…Making good use of channel designs and rotating forces to manipulate fluids, multiple laboratory procedures (e.g., mixing, valving, and sample splitting) can be processed in a single device, demonstrated by various CD-based biomedical systems such as immunoassay [15], high-throughput DNA array [16], colorimetric assays for detecting biochemical markers [17], nucleic acid amplification (PCR) assay, etc. These integrating techniques and efficient fluid control capabilities have recently guided a number of automated blood analysis systems [18] and an all-in-one centrifugal microfluidic device [19] representing considerable advancement of centrifugal microfluidic systems in point-of-care diagnostics [20].…”