A Novel Microfluidic Point-of-Care Biosensor System on Printed Circuit Board for Cytokine Detection

Abstract

Point of Care (PoC) diagnostics have been the subject of considerable research over the last few decades driven by the pressure to detect diseases quickly and effectively and reduce healthcare costs. Herein, we demonstrate a novel, fully integrated, microfluidic amperometric enzyme-linked immunosorbent assay (ELISA) prototype using a commercial interferon gamma release assay (IGRA) as a model antibody binding system. Microfluidic assay chemistry was engineered to take place on Au-plated electrodes within an assay cell on a printed circuit board (PCB)-based biosensor system. The assay cell is linked to an electrochemical reporter cell comprising microfluidic architecture, Au working and counter electrodes and a Ag/AgCl reference electrode, all manufactured exclusively via standard commercial PCB fabrication processes. Assay chemistry has been optimised for microfluidic diffusion kinetics to function under continual flow. We characterised the electrode integrity of the developed platforms with reference to biological sampling and buffer composition and subsequently we demonstrated concentration-dependent measurements of H2O2 depletion as resolved by existing FDA-validated ELISA kits. Finally, we validated the assay technology in both buffer and serum and demonstrate limits of detection comparable to high-end commercial systems with the addition of full microfluidic assay architecture capable of returning diagnostic analyses in approximately eight minutes.

Microfluidic Point-of-Care Devices: New Trends and Future Prospects for eHealth Diagnostics

“…Other proposals combine microfluidics, magnetic nanoparticles, and electrochemical analysis for precise, rapid, and highly sensitive detection of biomarkers [45][46][47] . Figure 1D depicts the fabrication steps of the microfluidic array using an inexpensive home cutter printer and low-cost materials for detection of breast cancer biomarkers [46].…”

“…The fabrication process comprises four main steps, labeled i-iv in Figure 1D. Another electrochemical device for amperometric enzyme-linked immunosorbent assay (ELISA) [45] had a microfluidic cell printed on a circuit board, as shown in Figure 1E. The assay area (microfluidic channel) consists of a polymer protected gold-strip connected to inlet and outlet ports.…”

Affinity biosensors developed with quantum dots in microfluidic systems

“…The advantages of these platforms in comparison with standard procedures are reduced time of incubation steps, low volume consumption, miniaturization of whole biosensing concept, shortening response time, simplicity in usage, enabling to measure multi targets [ 14 ], and multi analyzer on unique platform [ 108 ]. Microfluidic channels could be easily reusable by flushing and removing the particles then introducing fresh solutions or solutions of carrier supports [ 72 , 109 , 110 ].…”

Modular Pressure and Flow Rate-Balanced Microfluidic Serial Dilution Networks for Miniaturised Point-of-Care Diagnostic Platforms

“…The main advantage of the LoPCB technology is that it could provide an analytical platform, where the microfluidic components for sample preparation and reagent manipulation can be integrated with electrochemical sensors and bespoke circuitry, generating a monolithic device [ 29 , 30 , 31 , 32 ]. Since there is no need for separate electronics and assay platforms, the required footprint of the whole measuring setup decreases, providing direct, more efficient electrochemical sensing in smaller areas/volume, contrary to, for example, bulky high-sensitivity spectrometric apparatus [ 33 , 34 ]. The combination of both, biochemistry and appropriate electronics on the same platform could reduce noise interference from the various electrical interconnections and as a result may improve the measurement’s signal-to-noise ratio (SNR) [ 35 ].…”