Simultaneous detection of five indices of hepatitis B based on an integrated automatic microfluidic device

Abstract

Immunophenotyping evaluation is of particular importance for the clinical diagnosis, therapy, and prognosis of viral hepatitis. In this study, an integrated micro flow device has been developed to detect the differentiated antigens/antibodies for immunophenotyping of viral hepatitis. The sensors were fabricated with plasma-polymerized ethylenediamine film (PPF) and nanometer-sized gold particles (nanogold) on which the different hepatitis B antigens/antibodies (markers) were subsequently immobilized. Monitoring the changes in the potential signals before and after the antigen-antibody interaction provides the basis for an immunoassay that is simple, rapid, and cost-effective. It permits the detection of hepatitis B in the dynamic concentration range of 2 orders of magnitude (10(-6) g x L(-1) - 10(-4) g x L(-1)). Up to 7 successive assay cycles with retentive sensitivity were achieved for the sensors regenerated by 8 M urea. Moreover, the microfluidic device was applied to evaluate a number of practical specimens with analytical results in acceptable agreement with those clinically classified. The newly proposed multiparameter analysis technique provides a feasible alternative tool for the diagnosis and monitoring of hepatitis B.

Internally calibrated quantification of VEGF in human plasma by fluorescence immunoassays in disposable elastomeric microfluidic devices

“…While it is prudent to debug emerging systems with buffer solutions as a preliminary step, the ultimate challenge is to produce good results with human serum, plasma, cerebrospinal fluid, urine, saliva, etc. With that requirement in place, the selection of demonstrated devices becomes far more limited [11, 21, 22, 25, 28, 29, 32, 36–38, 40, 42]. Except for a surface plasmon resonance method [25] (which is expensive and difficult to parallelize and miniaturize), our system is the apparent leader in quantitative sensitivity.…”

“…Many microfluidic immunoassay approaches have been proposed, involving glass [3–10], titanium dioxide [8], silicon [11–15], silicone [11, 16–31], silicon nitride [32], poly(methylmethacrylate) [33], polyurethane [34], Mylar [35], polycarbonate [36], polyolefin [37], ethylenediamine film [38], compact discs [39], flow cells [40], screen-printed chips [41], and scanned arrays [42]. These diverse efforts boast subsets of the full list of the desirable qualities: capability to measure multiple antigens and samples per device, industrially feasible fabrication, parsimony of sample and reagents, adequate sensitivity and specificity, adequate reliability and reproducibility, and robust performance in the field.…”

Highly sensitive poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] brush-based flow-through microarray immunoassay device

“…With advances in microfabrication, flow-through immunoassay has been developed as a promising technique to take advantages of fast detection, small consumption of reagents, miniaturization, automation, and much reduced chemical waste for high-throughput protein analyses (Gao et al 2005;Liang et al 2007;Park et al 2008;Yu et al 2009a). However, the existing flow-through devices are insufficient in sensitivity and specificity for practical applications due to poor protein probe loading and low Ab-Ag binding efficiency.…”

Heterogeneous immunoassays in microfluidic format using fluorescence detection with integrated amorphous silicon photodiodes

“…Thus, it is crucial to choose an appropriated detection method with high sensitivity and scalable to smaller dimensions. 27 The most common form of miniaturized detection is the use of electrochemical detection 9,14,19,[28][29][30][31][32] because of the ease of electrode miniaturization and integration in the microfluidic system. Optical detection has also been used in microfluidic immunoassays, such as fluorescence detection 7,15,20,21,33,34 using diode lasers coupled with PMT and appropriate wavelength filters.…”