16 research outputs found
Superwettable Electrochemical Biosensor toward Detection of Cancer Biomarkers
Bioinspired
superwettable micropatterns that combine two extreme
states of superhydrophobicity and superhydrophilicity with the ability
to enrich and absorb microdroplets are suitable for versatile and
robust sensing applications. Here we introduce a superwettable microchip
that integrates superhydrophobicâsuperhydrophilic micropatterns
and a nanodendritic electrochemical biosensor toward the detection
of prostate cancer biomarkers. On the superwettable microchip, the
superhydrophobic area could confine the microdroplets in superhydrophilic
microwells; such behavior is extremely helpful for reducing the amount
of analytical solution. In contrast, superhydrophilic microwells exhibit
a high adhesive force toward microdroplets, and the nanodendritic
structures can improve probe-binding capacity and response signals,
thus greatly enhancing the sensitivity. Sensitive and selective detection
of prostate cancer biomarkers including miRNA-375, miRNA-141, and
prostate-specific antigen on a single microchip is also achieved.
Such a superwettable microchip with high sensitivity, low sample volume,
and upside-down detection capability in a single microdroplet shows
great potential to fabricate portable devices toward complex biosensing
applications
Fully Integrated Ratiometric Fluorescence Enrichment Platform for High-Sensitivity POC Testing of Salivary Cancer Biomarkers
The point-of-care (POC) testing of
cancer biomarkers
in saliva
with both high sensitivity and accuracy remains a serious challenge
in modern clinical medicine. Herein, we develop a new fully integrated
ratiometric fluorescence enrichment platform that utilizes acoustic
radiation forces to enrich dual-emission sandwich immune complexes
for a POC visual assay. As a result, the color signals from red and
green fluorescence (capture probe and report probe, respectively)
are enhanced by nearly 10 times, and colorimetric sensitivity is effectively
improved. When illuminated using a portable UV lamp, the fluorescence
color changing from red to green can be clearly seen with the naked
eye, which allows a semiqualitative assessment of the carcinoembryonic
antigen (CEA) level. In combination with a homemade smartphone-based
portable device, cancer biomarkers like CEA are quantified, achieving
a limit of detection as low as 0.012 ng/mL. We also directly quantify
CEA in human saliva samples to investigate the reliability of this
fully integrated platform, thus validating the usefulness of the proposed
strategy for clinical diagnosis and home monitoring of physical conditions
MagnetoâAcoustic Hybrid Nanomotor
Efficient and controlled nanoscale
propulsion in harsh environments requires careful design and manufacturing
of nanomachines, which can harvest and translate the propelling forces
with high spatial and time resolution. Here we report a new class
of artificial nanomachine, named magnetoâacoustic hybrid nanomotor,
which displays efficient propulsion in the presence of either magnetic
or acoustic fields without adding any chemical fuel. These fuel-free
hybrid nanomotors, which comprise a magnetic helical structure and
a concave nanorod end, are synthesized using a template-assisted electrochemical
deposition process followed by segment-selective chemical etching.
Dynamic switching of the propulsion mode with reversal of the movement
direction and digital speed regulation are demonstrated on a single
nanovehicle. These hybrid nanomotors exhibit a diverse biomimetic
collective behavior, including stable aggregation, swarm motion, and
swarm vortex, triggered in response to different field inputs. Such
adaptive hybrid operation and controlled collective behavior hold
considerable promise for designing smart nanovehicles that autonomously
reconfigure their operation mode according to their mission or in
response to changes in their surrounding environment or in their own
performance, thus holding considerable promise for diverse practical
biomedical applications of fuel-free nanomachines
Fully Integrated Ratiometric Fluorescence Enrichment Platform for High-Sensitivity POC Testing of Salivary Cancer Biomarkers
The point-of-care (POC) testing of
cancer biomarkers
in saliva
with both high sensitivity and accuracy remains a serious challenge
in modern clinical medicine. Herein, we develop a new fully integrated
ratiometric fluorescence enrichment platform that utilizes acoustic
radiation forces to enrich dual-emission sandwich immune complexes
for a POC visual assay. As a result, the color signals from red and
green fluorescence (capture probe and report probe, respectively)
are enhanced by nearly 10 times, and colorimetric sensitivity is effectively
improved. When illuminated using a portable UV lamp, the fluorescence
color changing from red to green can be clearly seen with the naked
eye, which allows a semiqualitative assessment of the carcinoembryonic
antigen (CEA) level. In combination with a homemade smartphone-based
portable device, cancer biomarkers like CEA are quantified, achieving
a limit of detection as low as 0.012 ng/mL. We also directly quantify
CEA in human saliva samples to investigate the reliability of this
fully integrated platform, thus validating the usefulness of the proposed
strategy for clinical diagnosis and home monitoring of physical conditions
Programmable Microparticle Array for In Situ Modification and Multiple miRNA Detection
Simultaneous detection of multiple miRNAs of one disease
can greatly
reduce misdiagnosis and improve the detection rate, which is helpful
for early cancer diagnosis. Here, a programmable microparticle-array-based
acoustic microchip for in situ simultaneous multiple miRNAs detection
is developed. On this microchip, the multiple probes-labeled microparticle
array can be procedurally arranged in a microfluidic reaction chamber
when four orthogonally piezoelectric transducers are applied. The
probes-labeled microparticle array offers a platform for full molecular
contact under dynamic ultrasonic streaming, and the array supplies
a multipoint data correction to reduce the false positive of the detection
results for more precisely visible fluorescence multiple target miRNAs
sensing. We employed miRNA-21, miRNA-210, and miRNA-155 as specific
biomarkers of pancreatic cancer and successfully finished the multiple
miRNAs simultaneous detection in the microchip with a detection limit
of 139.1, 179.9, and 111.4 pM, respectively. Such a device is programmable
by adjusting the imputing frequency and voltage, and target biomarkers
can be easily collected when the ultrasound force is released for
further analysis, which shows great potential in multiple miRNAs enrichment
and simultaneous detection for cancer clinical diagnosis
Programmable Microparticle Array for In Situ Modification and Multiple miRNA Detection
Simultaneous detection of multiple miRNAs of one disease
can greatly
reduce misdiagnosis and improve the detection rate, which is helpful
for early cancer diagnosis. Here, a programmable microparticle-array-based
acoustic microchip for in situ simultaneous multiple miRNAs detection
is developed. On this microchip, the multiple probes-labeled microparticle
array can be procedurally arranged in a microfluidic reaction chamber
when four orthogonally piezoelectric transducers are applied. The
probes-labeled microparticle array offers a platform for full molecular
contact under dynamic ultrasonic streaming, and the array supplies
a multipoint data correction to reduce the false positive of the detection
results for more precisely visible fluorescence multiple target miRNAs
sensing. We employed miRNA-21, miRNA-210, and miRNA-155 as specific
biomarkers of pancreatic cancer and successfully finished the multiple
miRNAs simultaneous detection in the microchip with a detection limit
of 139.1, 179.9, and 111.4 pM, respectively. Such a device is programmable
by adjusting the imputing frequency and voltage, and target biomarkers
can be easily collected when the ultrasound force is released for
further analysis, which shows great potential in multiple miRNAs enrichment
and simultaneous detection for cancer clinical diagnosis
Fully Integrated Ratiometric Fluorescence Enrichment Platform for High-Sensitivity POC Testing of Salivary Cancer Biomarkers
The point-of-care (POC) testing of
cancer biomarkers
in saliva
with both high sensitivity and accuracy remains a serious challenge
in modern clinical medicine. Herein, we develop a new fully integrated
ratiometric fluorescence enrichment platform that utilizes acoustic
radiation forces to enrich dual-emission sandwich immune complexes
for a POC visual assay. As a result, the color signals from red and
green fluorescence (capture probe and report probe, respectively)
are enhanced by nearly 10 times, and colorimetric sensitivity is effectively
improved. When illuminated using a portable UV lamp, the fluorescence
color changing from red to green can be clearly seen with the naked
eye, which allows a semiqualitative assessment of the carcinoembryonic
antigen (CEA) level. In combination with a homemade smartphone-based
portable device, cancer biomarkers like CEA are quantified, achieving
a limit of detection as low as 0.012 ng/mL. We also directly quantify
CEA in human saliva samples to investigate the reliability of this
fully integrated platform, thus validating the usefulness of the proposed
strategy for clinical diagnosis and home monitoring of physical conditions
Superwettable Microchips as a Platform toward Microgravity Biosensing
The
construction of the Space Station provides a spaceflight laboratory,
which enables us to accomplish tremendous short- and long-duration
research such as astronomy, physics, material sciences, and life sciences
in a microgravity environment. Continuous innovation and development
of spaceflight laboratory prompted us to develop a facile detection
approach to meet stringent requirements in a microgravity environment
that traditional experimental approaches cannot reach. Here we introduce
superhydrophilic microwells onto superhydrophobic substrates that
are capable of capturing and transferring microdroplets, demonstrating
a proof-of-concept study of a biosensing platform toward microgravity
application. The capability of manipulating microdroplets originates
from the capillary force of the nanoscale dendritic coating in superhydrophilic
microwells. Based on theoretical modeling, capillary forces of the
superhydrophilic microwells can dominate the behavior of microdroplets
against the gravity. Direct naked-eye observation monitoring of daily
physiological markers, such as glucose, calcium, and protein can be
achieved by colorimetric tests without the requirement of heavy optical
or electrical equipment, which greatly reduced the weight, and will
bring a promising clue for biodetection in microgravity environments
Ultrasound-Modulated Bubble Propulsion of Chemically Powered Microengines
The use of an ultrasound (US) field
for rapid and reversible control
of the movement of bubble-propelled chemically powered PEDOT/Ni/Pt
microÂengines is demonstrated. Such operation reflects the US-induced
disruption of normal bubble evolution and ejection, essential for
efficient propulsion of catalytic microtubular engines. It offers
precise speed control, with sharp increases and decreases of the speed
at low and high US powers, respectively. A wide range of speeds can
thus be generated by tuning the US power. Extremely fast changes in
the motor speed (<0.1 s) and reproducible âOn/Offâ
activations are observed, indicating distinct advantages compared
to motion control methods based on other external stimuli. Such effective
control of the propulsion of chemically powered microÂengines,
including remarkable âbrakingâ ability, holds considerable
promise for diverse applications
Reversible Swarming and Separation of Self-Propelled Chemically Powered Nanomotors under Acoustic Fields
The
collective behavior of biological systems has inspired efforts
toward the controlled assembly of synthetic nanomotors. Here we demonstrate
the use of acoustic fields to induce reversible assembly of catalytic
nanomotors, controlled swarm movement, and separation of different
nanomotors. The swarming mechanism relies on the interaction between
individual nanomotors and the acoustic field, which triggers rapid
migration and assembly around the nearest pressure node. Such on-demand
assembly of catalytic nanomotors is extremely fast and reversible.
Controlled movement of the resulting swarm is illustrated by changing
the frequency of the acoustic field. Efficient separation of different
types of nanomotors, which assemble in distinct swarming regions,
is illustrated. The ability of acoustic fields to regulate the collective
behavior of catalytic nanomotors holds considerable promise for a
wide range of practical applications