A microfluidic electrochemiluminescent device for detecting cancer biomarker proteins

Abstract

We describe an electrochemiluminescence (ECL) immunoarray incorporated into a prototype microfluidic device for highly sensitive protein detection, and apply this system to accurate, sensitive measurements of prostate specific antigen (PSA) and interleukin-6 (IL-6) in serum. The microfluidic system employed three molded polydimethylsiloxane (PDMS) channels on a conductive pyrolytic graphite chip (PG) (2.5 × 2.5 cm) inserted into a machined chamber and interfaced with a pump, switching valve and sample injector. Each of the three PDMS channels encompasses three 3 μL analytical wells. Capture-antibody-decorated single-wall carbon nanotube (SWCNT) forests are fabricated in the bottom of the wells. The antigen is captured by these antibodies on the well bottoms. Then a RuBPY-silica-secondary antibody (Ab2) label is injected to bind to antigen on the array, followed by injection of sacrificial reductant tripropylamine (TPrA) to produce ECL. For detection, the chip is placed into an open-top ECL measuring cell, and the channels are in contact with electrolyte in the chamber. Potential applied at 0.95 V vs. SCE oxidizes TPrA to produce ECL by redox cycling the RuBPY species in the particles, and ECL light is measured by a CCD camera. This approach achieved ultralow detection limits (DL) of 100 fg mL-1 for PSA (9 zeptomol) and 10 fg mL-1 (1 zeptomol) for IL-6 in calf serum, a 10-25 fold improvement of a similar non-microfluidic array. PSA and IL-6 in synthetic cancer patient serum samples were detected in 1.1 h and results correlated well with single-protein ELISAs.

Imaging Analysis Based on Electrogenerated Chemiluminescence

“…And the array determinations of PSA and IL-6 in patient serum were performed and wellcorrelated with single-protein ELISA [99]. In addition, this ECL immunearray was incorporated into a microfluidic device for sensitive measurements of cancer biomarker proteins in serum [100,101]. By using the 3D printing technique, the supercapacitor-powered ECL protein immunoarray has also been fabricated [102].…”

Biomarker detection for disease diagnosis using cost-effective microfluidic platforms

“…45 . These microfluidic platforms includes glass, 21, 46, 47 polydimethylsiloxane (PDMS), 45, 48, 49 poly(methyl methacrylate) (PMMA), 36, 50, 51 poly(cyclic olefin), 52, 53 paper-based, 23, 54–59 and hybrid devices. 36, 60, 61 …”

Electrochemiluminescence on digital microfluidics for microRNA analysis

“…But such assays are tedious, requiring long processing regimens including particle conditioning and blocking, hybridization with sample, extensive wash-steps, mixing with ECL luminophores and coreactants, and (finally) detection. There have been a number of microfluidic systems combined with ECL detection described in the literature, some relying on enclosed microchannels Hsueh et al 1998;Hsueh et al 1996;Sardesai et al 2013;Silverbrook et al 2011), and others relying on lateral flow in paper or other absorptive media (Delaney et al 2011;Liu et al 2015;Mani et al 2013;Wang et al 2012;Yan et al 2013;Guan et al 2016), but we are unaware of any system that has been developed which integrates all of the steps required for magnetic-particle-based nucleic acid analyses.…”