Affiliations: Faculty of Engineering, Centre for Microsystems Technology, University of Ghent, Ghent-Zwijnaarde, Belgium | Interuniversity Microelectronics Centre, Leuven, Belgium | Department of Chemical Engineering, Universitat Rovira i Virgili, Tarragona, Spain | Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain | Science for Life Laboratory (SciLifeLab Stockholm), KTH Royal Institute of Technology, School of Biotechnology, Division of Gene Technology, Solna, Sweden
Note: [] Address for correspondence: P. Salvo, Faculty of Engineering, Centre for Microsystems Technology (CMST), University of Ghent, 914A Technologiepark, B-9052 Ghent-Zwijnaarde, Belgium. Tel.: +32 9 264 53 54; Fax: +32 9 264 53 74; E-mail: pietro.salvo@gmail.com
Abstract: The request of high specificity and selectivity sensors suitable for mass production is a constant demand in medical research. For applications in point-of-care diagnostics and therapy, there is a high demand for low cost and rapid sensing platforms. This paper describes the fabrication and functionalization of gold electrodes arrays for the detection of deoxyribonucleic acid (DNA) in printed circuit board (PCB) technology. The process can be implemented to produce efficiently a large number of biosensors. We report an electrolytic plating procedure to fabricate low-density gold microarrays on PCB suitable for electrochemical DNA detection in research fields such as cancer diagnostics or pharmacogenetics, where biosensors are usually targeted to detect a small number of genes. PCB technology allows producing high precision, fast and low cost microelectrodes. The surface of the microarray is functionalized with self-assembled monolayers of mercaptoundodecanoic acid or thiolated DNA. The PCB microarray is tested by cyclic voltammetry in presence of 5 mM of the redox probe K3Fe(CN6) in 0.1 M KCl. The voltammograms prove the correct immobilization of both the alkanethiol systems. The sensor is tested for detecting relevant markers for breast cancer. Results for 5 nM of the target TACSTD1 against the complementary TACSTD1 and non-complementary GRP, MYC, SCGB2A1, SCGB2A2, TOP2A probes show a remarkable detection limit of 0.05 nM and a high specificity.
Keywords: Printed circuit board gold electrodes, electrolytic plating, surface functionalization, thiolated DNA probes, breast cancer markers detection
