Wearable Biosensor with Molecularly Imprinted Conductive Polymer Structure to Detect Lentivirus in Aerosol.

The coronavirus disease (COVID-19) pandemic has increased pressure to develop low-cost, compact, user-friendly, and ubiquitous virus sensors for monitoring infection outbreaks in communities and preventing economic damage resulting from city lockdowns. As proof of concept, we developed a wearable paper-based virus sensor based on a molecular imprinting technique, using a conductive polyaniline (PANI) polymer to detect the lentivirus as a test sample. This sensor detected the lentivirus with a 4181 TU/mL detection limit in liquid and 0.

Nurse-Administered Auricular Point Acupressure for Cancer-Related Pain.

Purpose: The study aimed to (1) examine the feasibility of providing a training course on auricular point acupressure (APA) for clinical oncology nurses to integrate APA into real-world nursing care settings, and (2) examine the effectiveness of APA on cancer-related pain (CRP) under usual inpatient oncology ward conditions.

Methods: This was a 2-phase feasibility study. Phase 1, an in-person, 8 hour training program was provided to oncology nurses.

A hydraulic soft microgripper for biological studies.

We have developed a microscale hydraulic soft gripper and demonstrated the handling of an insect without damage. This gripper is built on Polydimethylsiloxane (PDMS) with the soft material casting technique to form three finger-like columns, which are placed on a circular membrane. The fingers have a length of 1.

A Hybrid Structure of Piezoelectric Fibers and Soft Materials as a Smart Floatable Open-Water Wave Energy Converter.

An open-water wave energy converter (OWEC) made of a new soft platform has been developed by combining piezoelectric macro-fiber composites (MFCs) and a low-cost elastomer. In the past decades, numerous types of water wave energy conversion platform have been developed and investigated, from buoys to overtopping devices. These harvesters mainly use electromagnetic-based generators, and they have faced challenges such as their enormous size, high deployment and maintenance costs, and negative effects on the environment.

Perfluorooctanesulfonic Acid Detection Using Molecularly Imprinted Polyaniline on a Paper Substrate.

Perfluorinated compounds like perfluorooctanesulfonic acid (PFOS) are synthetic water pollutants and have accumulated in environments for decades, causing a serious global health issue. Conventional assays rely on liquid chromatography and mass spectroscopy that are very expensive and complicated and thus limit the large-scale monitoring of PFOS in wastewater. To achieve low-cost and accurate detection of PFOS, we designed a paper-based sensor with molecularly imprinted polyaniline electrodes that have recognition sites specific to PFOS.

A Low-cost and Enzyme-free Glucose Paper Sensor.

A low-cost and enzyme-free glucose paper sensor is presented as a promising alternative to glucose test strips. This paper-based glucose sensor is prepared with molecularly imprinted (MIP) polyaniline (PANI) electrode. The determination of glucose concentrations was studied by the impedance change of the paper sensor before and after the blood samples dispensing at a low frequency.

Isolation of cancer-derived extracellular vesicle subpopulations by a size-selective microfluidic platform.

Extracellular vesicles (EVs) play an important role in intercellular communication. Recently, there has been increasing interest in EVs as potential diagnostic biomarkers and therapeutic vehicles. However, the molecular properties and cargo information of EV subpopulations have not yet been fully investigated due to lack of reliable and reproducible EV separation technology.

A Low-Cost Paper Glucose Sensor with Molecularly Imprinted Polyaniline Electrode.

For the hundreds of millions of worldwide diabetic patients, glucose test strips are the most important and commonly used tool for monitoring blood glucose levels. Commercial test strips use glucose oxidases as recognition agents, which increases the cost and reduces the durability of test strips. To lower the cost of glucose sensors, we developed a paper-based electrical sensor with molecularly imprinted glucose recognition sites and demonstrated the determination of various glucose concentrations in bovine blood solutions.

Digital Receptor Occupancy Assay in Quantifying On- and Off-Target Binding Affinities of Therapeutic Antibodies.

While monoclonal antibodies are the fastest-growing class of therapeutic agents, we lack a method that can directly quantify the on- and off-target binding affinities of newly developed therapeutic antibodies in crude cell lysates. As a result, some therapeutic antibody candidates could have a moderate on-target binding affinity but a high off-target binding affinity, which not only gives a reduced efficacy but triggers unwanted side effects. Here, we report a single-molecule counting method that precisely quantifies antibody-bound receptors, free receptors, and unbound antibodies in crude cell lysates, termed digital receptor occupancy assay (DRO).

Development of size-selective microfluidic platform.

Exosomes are nanosized extracellular vesicles that play a significant role in cell-cell communication. Recently, there is significant interest in exosome-related fundamental research, especially subgroups of exosomes as potential biomarkers for cancer diagnosis and prognosis. In this paper, we report a new size selective isolation method via elastic lift force and nanomembrane filtration and demonstrated the liposome recovery rate of 92.

Reusable Functionalized Hydrogel Sorbents for Removing Long- and Short-Chain Perfluoroalkyl Acids (PFAAs) and GenX from Aqueous Solution.

Per- and poly-fluoroalkyl substances (PFASs) are man-made chemicals that are toxic and widely detected in the environment, including drinking water sources. A cost-effective treatment process for PFASs is currently not available. We developed reusable hydrogel sorbents to remove long- and short-chain perfluoroalkyl acids and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid (GenX), which is are emerging PFAS.

A flow-proteometric platform for analyzing protein concentration (FAP): Proof of concept for quantification of PD-L1 protein in cells and tissues.

Protein expression level is critically related to the cell physiological function. However, current methodologies such as Western blot (WB) and Immunohistochemistry (IHC) in analyzing the protein level are rather semi-quantitative and without the information of actual protein concentration. We have developed a microfluidic technique termed a "flow-proteometric platform for analyzing protein concentration (FAP)" that can measure the concentration of a target protein in cells or tissues without the requirement of a calibration standard, e.

Pneumatically Actuated Soft Micromold Device for Fabricating Collagen and Matrigel Microparticles.

Collagen microparticles have recently gained more attention as viable cell confinement blocks in many biomedical research fields. Small volume and high surface area of collagen structure improve cell confinement, viability, and proliferation. Moreover, dense collagen fiber structure can protect cells from immune destruction.

A magneto-fluidic nanoparticle trapping platform for surface-enhanced Raman spectroscopy.

A microfluidic device utilizing magnetically activated nickel (Ni) micropads has been developed for controlled localization of plasmonic core-shell magnetic nanoparticles, specifically for surface enhanced Raman spectroscopy (SERS) applications. Magnetic microfluidics allows for automated washing steps, provides a means for easy reagent packaging, allows for chip reusability, and can even be used to facilitate on-chip mixing and filtration towards full automation of biological sample processing and analysis. Milliliter volumes of gold-coated 175-nm silica encapsulated iron oxide nanoparticles were pumped into a microchannel and allowed to magnetically concentrate down into 7.

Novel 3D coaxial flow-focusing nozzle device for the production of monodispersed collagen microspheres.

We have developed a 3D coaxial flow-focusing nozzle device for the mass production of monodispersed collagen microspheres and chemically crosslinked them using EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) and N-hydroxysuccinimide (NHS). The size of the microspheres was varied between 200 μm and 600 μm by adjusting the ratio of the flow rates of the dispersed and continuous phases. MDA231-GFP cells were attached to the surface of these particles and their viability was investigated.

Ferric plasmonic nanoparticles, aptamers, and magnetofluidic chips: toward the development of diagnostic surface-enhanced Raman spectroscopy assays.

Conjugation of aptamers and their corresponding analytes onto plasmonic nanoparticles mediates the formation of nanoparticle assemblies: molecularly bound nanoclusters that cause a measurable change in the colloid’s optical properties. The optimization of a surface-enhanced Raman spectroscopy (SERS) competitive binding assay utilizing plasmonic “target” and magnetic “probe” nanoparticles for the detection of the toxin bisphenol-A (BPA) is presented. These assay nanoclusters were housed inside three types of optofluidic chips patterned with magnetically activated nickel pads, in either a straight or array pattern.

Fabrication of Bacteria Environment Cubes with Dry Lift-Off Fabrication Process for Enhanced Nitrification.

We have developed a 3D dry lift-off process to localize multiple types of nitrifying bacteria in polyethylene glycol diacrylate (PEGDA) cubes for enhanced nitrification, a two-step biological process that converts ammonium to nitrite and then to nitrate. Ammonia-oxidizing bacteria (AOB) is responsible for converting ammonia into nitrite, and nitrite-oxidizing bacteria (NOB) is responsible for converting nitrite to nitrate. Successful nitrification is often challenging to accomplish, in part because AOB and NOB are slow growers and highly susceptible to many organic and inorganic chemicals in wastewater.

Use of a micro- to nanochannel for the characterization of surface-enhanced Raman spectroscopy signals from unique functionalized nanoparticles.

A micro- to nanochannel nanoparticle aggregating device that does not require any input energy to organize the particles to a specific location, i.e., no pumps, plugs, heat, or magnets, has been designed and used to characterize the surface-enhanced Raman spectroscopy (SERS) signal from four unique functionalized nanoparticles (gold, silver-gold nanocages, silver nanocubes, and silica-gold nanoshells).

Analysis of Individual Signaling Complexes by mMAPS, a Flow-Proteometric System.

Signal transduction is essential for maintaining normal cell physiological functions, and deregulation of signaling can lead to diseases such as diabetes and cancers. Some of the major players in signal delivery are molecular complexes composed of proteins and nucleic acids. This unit describes a technique called microchannel for multiparameter analysis of proteins in a single complex (mMAPS) for analyzing and quantifying individual target signaling complexes.

mMAPS: a flow-proteometric technique to analyze protein-protein interactions in individual signaling complexes.

Signal transduction is a dynamic process that regulates cellular functions through multiple types of biomolecular interactions, such as the interactions between proteins and between proteins and nucleic acids. However, the techniques currently available for identifying protein-protein or protein-nucleic acid complexes typically provide information about the overall population of signaling complexes in a sample instead of information about the individual signaling complexes therein. We developed a technique called "microchannel for multiparameter analysis of proteins in a single complex" (mMAPS) that simultaneously detected individual target proteins either singly or in a multicomponent complex in cell or tissue lysates.

Microfluidic three-dimensional hydrodynamic flow focusing for the rapid protein concentration analysis.

A simple microfluidic 3D hydrodynamic flow focusing device has been developed and demonstrated quantitative determinations of quantum dot 525 with antibody (QD525-antibody) and hemagglutinin epitope tagged MAX (HA-MAX) protein concentrations. This device had a step depth cross junction structure at a hydrodynamic flow focusing point at which the analyte stream was flowed into a main detection channel and pinched not only horizontally but also vertically by two sheath streams. As a result, a triangular cross-sectional flow profile of the analyte stream was formed and the laser was focused on the top of the triangular shaped analyte stream.

Collagen microsphere production on a chip.

We have developed an integrated microfluidic material processing chip and demonstrated the rapid production of collagen microspheres encapsulating cells with high uniformity and cell viability. The chip integrated three material processing steps. Monodisperse microdroplets were generated at a microfluidic T junction between aqueous and mineral oil flows.

MEASUREMENT of Protein 53 Diffusion Coefficient in Live HeLa Cells Using Raster Image Correlation Spectroscopy (RICS).

We have applied Raster Image Correlation Spectroscopy (RICS) technique to characterize the dynamics of protein 53 (p53) in living cells before and after the treatment with DNA damaging agents. HeLa cells expressing Green Fluorescent Protein (GFP) tagged p53 were incubated with and without DNA damaging agents, cisplatin or eptoposide, which are widely used as chemotherapeutic drugs. Then, the diffusion coefficient of GFP-p53 was determined by RICS and it was significantly reduced after the drug treatment while that of the one without drug treatment was not.

Rapid prototyping of nanofluidic systems using size-reduced electrospun nanofibers for biomolecular analysis.

Biomolecular transport in nanofluidic confinement offers various means to investigate the behavior of biomolecules in their native aqueous environments, and to develop tools for diverse single-molecule manipulations. Recently, a number of simple nanofluidic fabrication techniques has been demonstrated that utilize electrospun nanofibers as a backbone structure. These techniques are limited by the arbitrary dimension of the resulting nanochannels due to the random nature of electrospinning.