Integrated microfluidic platform for the electrochemical detection of breast cancer markers in patient serum samples

Abstract

A microsystem integrating electrochemical detection for the simultaneous detection of protein markers of breast cancer is reported. The microfluidic platform was realized by high precision milling of polycarbonate sheets and features two well distinguishable sections: a detection zone incorporating the electrode arrays and the fluid storage part. The detection area is divided into separate microfluidic chambers addressing selected electrodes for the measurement of samples and calibrators. The fluidic storage part of the platform consists of five reservoirs to store the reagents and sample, which are interfaced by septa. These reservoirs have the appropriate volume to run a single assay per cartridge and are manually filled. The liquids from the reservoirs are actuated by applying a positive air pressure (i.e.via a programmable syringe pump) through the septa and are driven to the detection zone via two turning valves. The application of the realised platform in the individual and simultaneous electrochemical detection of proteic cancer markers with very low detection limits are demonstrated. The microsystem has also been validated using real patient serum samples and excellent correlation with ELISA results obtained.

Automated microsystem for electrochemical detection of cancer markers

“…The simplest protocol consists of carrying out the calibration of the sensor first, followed by sample analysis. This protocol requires about 15 min in total to be executed, considering that the incubation time for both analyte and reporter antibody is 2 min for each step [17]. In a second protocol, the fluidic functions are intercalated.…”

“…Details on the fabrication of the electrode arrays and microfluidic cartridge have been reported elsewhere [16,17]. The working electrodes were spotted with 5 mL of a stock solution of DT2 for 3 h followed by rinsing with copious amounts of ACN.…”

“…Monoclonal anti-CEA and anti-CA15-3 antibodies were kindly provided by Fujirebio Diagnostics AB (Göteborg, Sweden). HRP conjugates of anti-CEA and anti-CA15-3 were prepared as reported previously [17].…”

“…The bonding of the electrode arrays was realized via a laser-machined doublesided adhesive gasket that facilitated the creation of the microchannels necessary for the sample and reagent delivery. More recently, this microfabrication technology was applied for the development of a microsystem integrating electrochemical detection for the simultaneous detection of protein markers of breast cancer [17]. This more advanced microfluidic platform featured two well distinguishable sections: a detection zone incorporating the electrode arrays and a fluid storage part containing five reservoirs to store the reagents and sample and that have the appropriate volume to run a single assay per cartridge (Fig.…”

Application of thin metal film elements in bioanalysis

“…In another arrangement, microfluidic sensor with human cytochrome P450 3A4 covalently bound to working electrode was used for electrochemical determination of catalytic parameters of quinidine, nifedipine, alosetron and ondansetron [30]. Microfluidic immunoassay platform with independently addressable three-electrode cells and fluid part for reagents storage and transport was used for breast cancer markers detection in real samples [31]. Combination of microfluidic transport with electrochemical sensing was also described for detection of urinary proteins [32] and for fast detection of extremely lethal toxic substances such as botulinum neurotoxin [10].…”