A Fully Microfabricated Electrochemical Sensor and its Implementation for Detection of Methicillin Resistance in <italic>Staphylococcus Aureus</italic>

Abstract

On-chip detection of biological analytes can enable diagnosis at the point of care. Combining the advantages of microelectromechanical system (MEMS) technology and molecular methods, we present the design of an integrated microfluidic platform, a microelectrochemical sensor (µECS), and its implementation for the detection of methicillin resistance in Staphylococcus aureus. This platform is capable of electrochemically sensing the target analyte in a microfluidic reactor without the usage of bulky electrodes, rendering it useful for in vitro diagnostics. In our experiments, the functionality of the sensor was tested for detecting specific DNA sequences of mecA gene (an indicator of methicillin resistance) over a range of concentrations of DNA (down to 10 pM). Synthetic oligonucleotides and bacterial PCR product were used as a target analyte in Hoechst 33258 marker-based detection and horseradish peroxidase-based detection, respectively. The results revealed that this platform has high sensitivity and selectivity. Also, its compatibility to MEMS processes enables its use with different applications ranging from detecting various types of cancers to endemics. The designed µECS can enable the detection of biological analytes of interest at low cost and high throughput.

A review of microfabricated electrochemical biosensors for DNA detection

“…The use of microfluidic cells has also been shown to improve thin film biosensor performance, as well as moving the technology towards point of care applications (Berdat et al, 2007;Koydemir et al, 2014). This improvement in sensing performance was evidenced by Horny et al who compared a standard 25 μm diameter gold wire microelectrode, with a thin film 30 μm wide band microelectrode set in a microfluidic channel (Horny et al, 2016) Parylene -C is a polymer commonly used in the microfabrication industry for insulation and can be deposited conformally, without pinholes.…”

“…It has advantages over PDMS in that it is not oxygen permeable, although it can be challenging to deposit and pattern in thicknesses greater than single microns. Koydemir et al used Parylene -C to create a simple on-chip microfluidic system and demonstrated detection of synthetic MRSA target DNA down to 10 pM, with a maximum thickness of Parylene -C of approximately 20 μm (Koydemir et al, 2014). PMMA is another alternative to PDMS and was put to use by Liu et al who fabricated a sophisticated microfluidic system designed for processing blood samples, shown in figure 4 (Liu et al, 2018).…”

Research advance in rapid detection of foodborne Staphylococcus aureus

“…[45] S. aureus cells were detected in pure culture at concentrations as low as 1000 cells/mL in a relatively short assay time of 30 min by the immunosensor. [46] Biosensor detection method is fast and can be used for the detection of many substances. However, many of them are still in the research stage at present with high cost, which is not conducive to the promotion of the technology.…”

Solution-based nanosensors for in-field detection with the naked eye

“…For many years electrochemical sensors have dominated the area of in-field sensing due to the possibility of fabricating all the elements of the sensor with well-known microfabrication techniques. 6,7 These fabrication methods generate portable, compact devices in which the transducers are directly integrated with the circuitry. 8,9 However, although microchips containing electrochemical transducers can be mass-produced, the manufacturing cost of these devices is still too high for certain applications in which the sensor cannot be reutilised or recycled.…”