A team of researchers from the National University of
Singapore (NUS) developed
an innovative microfluidic chip that promise for a faster and cheaper way to
diagnose diseases with high accuracy.
Professor Zhang Yong from the Department of Biomedical
Engineering at the NUS Faculty of Engineering and his team have developed a
tiny microfluidic chip that could effectively detect minute amounts of
biomolecules without the need for complex lab equipment.
The low-cost microfluidic chip can quickly and
accurately detect and quantify nano-bioparticles using only a standard
laboratory microscope without any fluorescent labels.
“Our invention is an example of disruptive diagnostics. This
tiny biochip can sensitively detect proteins and nano-sized polymer vesicles
with a concentration as low as 10ng/mL (150 pM) and 3.75μg/mL respectively. It
also has a very small footprint, weighing only 500 mg and is 6mm³ in size.
Detection can be performed using standard laboratory microscopes, making this
approach highly attractive for use in point-of-care diagnostics,” explained
Prof Zhang.
Disease diagnosis requires identification and quantification
of various bioparticles such as DNA, RNA, proteins, virus, exosomes, and
bacteria. Typically, detection of biomolecules using colorimetric assays or
fluorescent labelling increase detection cost and complexity as they rely on
expensive optical systems and involvement of multiple sample processing steps
requiring minimum sample volumes.
One alternative to reduce cost in disease diagnosis is the
adoption of fluorescent label-free bioparticle detection techniques. This
approach requires precision engineering of nano-features in a detection chip,
complex optical setups, novel nano-probes such as graphene oxide, carbon
nanotubes, and gold nanorods, or additional amplification steps such as
aggregation of nanoparticles to achieve sensitive detection of biomarkers.
The innovation by the NUS team adopts the novel fluorescent
label-free approach that uses the lateral shifts in the position of the
microbead substrate in pillar arrays, for quantifying the biomolecules, based
on the change in surface forces and size, without the need of any external
equipment.
Due to the usage of lateral displacement, the
nano-biomolecules can be detected in real-time and the detection is
significantly faster in comparison to fluorescent label based detection.
“These techniques can also be extended to many other types
of nano-biomolecules, including nucleic acid and virus detection,” said Prof
Zhang.
To complement this chip technology, Prof Zhang said his team
is also developing a portable smartphone-based accessory and microfluidic pump
to make the whole detection platform portable for outside laboratory disease
diagnostics, in the hope of further developing this technology for
commercialisation.
His team, comprising Dr Kerwin Kwek Zeming and two NUS PhD
students Mr Thoriq Salafi and Ms Swati Shikha, published their findings in
scientific journal Nature
Communications on 28 March 2018.
This study was supported by a research grant
from the Singapore Ministry of Education.
