Point-of-care (PoC) biosensors continue to gain popularity because of the desire to improve cost performance in today’s health care industry. As cardiovascular disease (CVD) remains one of the top three leading causes of death in Asia, a tool that can help to detect CVDs is highly sought after. We present a high-sensitivity PoC biosensor that can be used to detect CVD biomarkers. To meet the requirements of a PoC biosensor, we adopted electrochemical methods as the basis of the detection. A more stable three-electrode configuration was miniaturized and put onto a biochip. To improve the detection sensitivity associated with the reduced size in the biochip, computer simulation was used to investigate several potential effective possibilities. We found that the electrolyte current density on the edge near the working electrode (WE) and counter electrode (CE) was higher. This was verified using an atomic force microscope to measure the surface potential. We then experimented with the configuration by lengthening the edge of the WE and CE without changing the area of the WE and CE and maintained the gap between the two electrodes. We found improved measurement efficiency with our newly developed biochip.
Development of point-of-care biosensors continues to gain popularity due to the demand of improving the cost performance in today’s health care. As cardiovascular disease induced death remains on the top 3 death causes for most Asian countries, this paper is to present a high-sensitivity point-of-care biosensor for the detection of cardiovascular disease biomarkers. To meet the point-of-care biosensors requirements, which include characteristics such as small size, low cost, and ease of operation, we adopted electrochemical methods as the basis of detection. The 4-aminothiophenol was adopted as the bio-linkers to facilitate the antibody-antigen interaction. A more stable three-electrode configuration was miniaturized and laid out onto a biochip. A microfluidics subsystem based on opto-piezoelectronic technology was also integrated to create the microfluidic biochip system. To improve the detection sensitivity associated with the reduction in biochip size, electrochemistry simulation was used to investigate several potentially effective means. We found that the electric field on the edge near working electrode and counter electrode was higher, which was verified by using atomic force microscopy to measure the surface potential. With the successful verification, we explored the configuration, i.e., lengthened the edge of working electrode and counter electrode without changing the areas of working electrode and counter electrode and the gap between these two electrodes, so as to evaluate the possibility of improving the measurement efficiency in our newly developed biochips. Detailed design, simulation and experimental results, improved design identified, etc. were all presented in detail.
Tuberculosis (TB) is an ancient disease constituted a long-term menace to public health. According to World Health
Organization (WHO), mycobacterium tuberculosis (MTB) infected nearly a third of people of the world. There is about
one new TB occurrence every second. Interferon-gamma (IFN-γ) is associated with susceptibility to TB, and interferongamma
release assays (IGRA) is considered to be the best alternative of tuberculin skin test (TST) for diagnosis of latent
tuberculosis infection (LTBI). Although significant progress has been made with regard to the design of enzyme
immunoassays for IFN-γ, adopting this assay is still labor-intensive and time-consuming. To alleviate these drawbacks,
we used IFN-γ antibody to facilitate the detection of IFN-γ.
An experimental verification on the performance of IGRA was done in this research. We developed two biosensor
configurations, both of which possess high sensitivity, specificity, and rapid IFN-γ diagnoses. The first is the
electrochemical method. The second is a circular polarization interferometry configuration, which incorporates two light
beams with p-polarization and s-polarization states individually along a common path, a four photo-detector quadrature
configuration to arrive at a phase modulated ellipsometer. With these two methods, interaction between IFN-γ antibody
and IFN-γ were explored and presented in detail.