Design and testing of a packaged microfluidic cell for the multiplexed electrochemical detection of cancer markers

Abstract

We present the rapid prototyping of electrochemical sensor arrays integrated to microfluidics towards the fabrication of integrated microsystems prototypes for point-of-care diagnostics. Rapid prototyping of microfluidics was realised by high-precision milling of polycarbonate sheets, which offers flexibility and rapid turnover of the desired designs. On the other hand, the electrochemical sensor arrays were fabricated using standard photolithographic and metal (gold and silver) deposition technology in order to realise three-electrode cells comprising gold counter and working electrodes as well as silver reference electrode. The integration of fluidic chips and electrode arrays was realised via a laser-machined double-sided adhesive gasket that allowed creating the microchannels necessary for sample and reagent delivery. We focused our attention on the reproducibility of the electrode array preparation for the multiplexed detection of tumour markers such as carcinoembryonic antigen and prostate-specific antigen as well as genetic breast cancer markers such as estrogen receptor-alpha, plasminogen activator urokinase receptor, epidermal growth factor receptor and erythroblastic leukemia viral oncogene homolog 2. We showed that by carefully controlling the electrode surface pre-treatment and derivatisation via thiolated antibodies or short DNA probes that the detection of several key health parameters on a single chip was achievable with excellent reproducibility and high sensitivity.

Electrochemical Arrays for Bioassay Applications

“…An array of sixteen 1 Â 1 mm 2 gold electrodes, with each sandwiched between a 0.2 Â 1 mm 2 gold counter and 0.2 Â 1 mm 2 silver pseudoreference electrodes, has been incorporated into a planar packaged microfluidic device for the detection of Electrochemical Arrays for Bioassay Applications cancer biomarkers [59]. Derivatization of the electrode surfaces using thiolated antibodies or short DNA probes allowed the detection of various tumor markers on a single chip.…”

Microfluidic Electrochemical Detection Techniques of Cancer Biomarkers

“…16 electrodes are arranged in the form of 4 × 4 in the middle of the "sandwich" type of chip, wherein the chip includes a fluid conduit, a sump, valves, and the detection electrode. 16 detection electrodes can handle the signals generated by CEA and PSA [52].…”

Automated microsystem for electrochemical detection of cancer markers

“…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.…”

“…We have previously reported the rapid prototyping of electrochemical sensor arrays by high-precision milling of polycarbonate sheets for the fabrication of integrated microsystem prototypes for use at the point-of-care [16]. These prototypes were composed of a microfluidic chip incorporating electrode arrays fabricated using standard photolithographic and metal deposition technologies.…”