Fabrication and functionalization of PCB gold electrodes suitable for DNA-based electrochemical sensing

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 K 3 Fe(CN 6 ) 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.

Commercially Fabricated Printed Circuit Board Sensing Electrodes for Biomarker Electrochemical Detection: The Importance of Electrode Surface Characteristics in Sensor Performance

“…While several PCB-implemented electrochemical biosensors are being increasingly demonstrated over the past few years for several applications [4][5][6][7][8][9], little care is being given to the sensing electrode characteristics and their significance in sensor characteristics. Nonetheless, in the case of sensors exploiting SAM-assisted capture molecule immobilization, the physical and chemical properties of the electrodes can severely affect the sensing characteristics.…”

Electrochemical Genetic Profiling of Single Cancer Cells

“…Electrode Chip Design. The printed circuit board (PCB) electrode array was manufactured at Fineline GmbH (Hilden, Germany), 15,26 using FR-4 glass epoxy resin with a Cu thickness of 30 μm as substrate with a surface finish of 3 μm soft gold electrolytically deposited on a nickel layer of 4 μm. The PCB-based chip has dimensions of 54.1 × 61.0 mm 2 , incorporating 64 individual working electrodes organized in four channels of 16 electrodes (Figure 1A).…”

“…Alternative metal patterning techniques such as standard printed circuit board (PCB) technology offers a low cost mass production and a number of versatile fabrication options. In recent years, there have been some reports of electrochemical arrays manufactured with this technology. ,− …”

The lab-on-PCB approach: tackling the μTAS commercial upscaling bottleneck

“…IMEC (ref. 131) presented in 2014 a study of PCB gold electrodes (Fig. 8B) exploited for the detection of DNA breast cancer related biomarkers, highlighting the cost effective upscalability advantage of this technology.…”