The group of scientists has managed to create a fluorescent label-free quantitative chip that can detect different diseases in a high-accurate and cost-effective way. This technology is based on measuring changes in size and/or electrostatic charges of 1 µm polymer beads due to the capture of target bioparticles on the surface. The method provides wide opportunities for various types of medical diagnosis such as liquid biopsy, detection of biologically relevant DNA, RNA, viruses, proteins, and exosomes.

The invention was made by the scientific group that includes Dr. Kerwin Kwek Zeming, Ph.D. student Mr. Thoriq Salafi and Ph.D. student Ms. Swati Shikha, led by Professor Zhang Yong from the NUS.

To diagnose certain illnesses doctors need to identify and classify various bioparticles such as DNA, RNA, proteins, virus, exosomes, and bacteria. Typical medical laboratories use determined sandwich assay, PCR, gel electrophoresis, and flow-cytometry technologies for identifying these bioparticles. Despite this fact, these technologies use the fluorescent label. It significantly increases the cost and complicacy due to the expensive optical systems using and applying of multiple sample processing steps, which require minimum sample contents.

The label-free technique can be a suitable alternative to decrease the cost and difficultness. Nevertheless, this unique method requires accurate engineering of nano-features in the detection chip. Furthermore, such technique needs intricate optical equipment, nano-probes or supplementary enhancement steps in order to achieve sensitive detection of biomarkers. 

Consequently, scientists developed a fluorescent label-free method for sensitive detection of bioparticles using a  micrometer-sized pillar array in a deterministic lateral displacement (DLD) device. The technology is based on the measurement of changes in size and electrostatic charges of 1 µm polymer beads catching target bioparticles on the surface. DLD pillar array platforms were used for size-sensitive separation of circulating tumor cells to bioparticles such as DNA and exosomes. The botanicals displaying is operated through lateral displacement changes as a result of the modulation of microbead surface charge or size induced by the adsorption of bioparticles. This innovational device has the ability to provide wide opportunities for different types of medical diagnostics methods such as liquid biopsy, detection of biologically relevant DNA, RNA, viruses, proteins, and exosomes.