Developing centrifugal force real-time digital PCR for detecting extremely low DNA concentration.

Digital PCR (dPCR) is a technique for absolute quantification of nucleic acid molecules. To develop a dPCR technique that enables more accurate nucleic acid detection and quantification, we established a novel dPCR apparatus known as centrifugal force real-time dPCR (crdPCR). This system is efficient than other systems with only 2.

3D Hierarchical Polyaniline-Metal Hybrid Nanopillars: Morphological Control and Its Antibacterial Application.

Effective and reliable antibacterial surfaces are in high demand in modern society. Although recent works have shown excellent antibacterial performance by combining unique hierarchical nanotopological structures with functional polymer coating, determining the antibacterial performance arising from morphological changes is necessary. In this work, three-dimensional (3D) hierarchical polyaniline-gold (PANI/Au) hybrid nanopillars were successfully fabricated via chemical polymerization (i.

All-in-One DNA Extraction Tube for Facilitated Real-Time Detection of Infectious Pathogens.

An "all-in-one tube" platform is developed, where the genetic analysis involving DNA extraction, amplification, and detection can be performed in a single tube. The all-in-one tube consists of a polymerase chain reaction (PCR) tube in which the inner surface is conformally modified with a tertiary-amine-containing polymer to generate a strong electrostatic interaction with DNA. The all-in-one tube provides high DNA capture efficiency exceeding 80% from Escherichia coli O157: H7 pathogen at a wide range of DNA amount from 0.

Flexible and highly ordered nanopillar electrochemical sensor for sensitive insulin evaluation.

In line with growing interest in obesity management, there has been an increase in the amount of research focused on highly sensitive analysis systems for a small number of biomarers. In this paper, we introduce the highly ordered nanopillar electrode, featuring a high aspect ratio surface area that enables enhanced electron transfer. For fabrication of the flexible electrode, gold was evaporated by electronic beam lithography on polyurethane (PU), which has high flexibility.

Extremely Fast Self-Healable Bio-Based Supramolecular Polymer for Wearable Real-Time Sweat-Monitoring Sensor.

Sensors with autonomous self-healing properties offer enhanced durability, reliability, and stability. Although numerous self-healing polymers have been attempted, achieving sensors with fast and reversible recovery under ambient conditions with high mechanical toughness remains challenging. Here, a highly sensitive wearable sensor made of a robust bio-based supramolecular polymer that is capable of self-healing via hydrogen bonding is presented.

A Disposable and Multi-Chamber Film-Based PCR Chip for Detection of Foodborne Pathogen.

Since the increment of the threat to public health caused by foodborne pathogens, researches have been widely studied on developing the miniaturized detection system for the on-site pathogen detection. In the study, we focused on the development of portable, robust, and disposable film-based polymerase chain reaction (PCR) chip containing a multiplex chamber for simultaneous gene amplification. In order to simply fabricate and operate a film-based PCR chip, different kinds of PCR chambers were designed and fabricated using polyethylene terephthalate (PET) and polyvinyl chloride (PVC) adhesive film, in comparison with commercial PCR, which employs a stereotyped system at a bench-top scale.

A film-based integrated chip for gene amplification and electrochemical detection of pathogens causing foodborne illnesses.

Given the increased interest in public hygiene due to outbreaks of food poisoning, increased emphasis has been placed on developing novel monitoring systems for point-of-care testing (POCT) to evaluate pathogens causing foodborne illnesses. Here, we demonstrate a pathogen evaluation system utilizing simple film-based microfluidics, featuring simultaneous gene amplification, solution mixing, and electrochemical detection. To minimize and integrate the various functionalities into a single chip, patterned polyimide and polyester films were mainly used on a polycarbonate housing chip, allowing simple fabrication and alignment, in contrast to conventional polymerase chain reaction, which requires a complex biosensing system at a bench-top scale.

A New Localization System for Indoor Service Robots in Low Luminance and Slippery Indoor Environment Using Afocal Optical Flow Sensor Based Sensor Fusion.

In this paper, a new localization system utilizing afocal optical flow sensor (AOFS) based sensor fusion for indoor service robots in low luminance and slippery environment is proposed, where conventional localization systems do not perform well. To accurately estimate the moving distance of a robot in a slippery environment, the robot was equipped with an AOFS along with two conventional wheel encoders. To estimate the orientation of the robot, we adopted a forward-viewing mono-camera and a gyroscope.

Portable vibration-assisted filtration device for on-site isolation of blood cells or pathogenic bacteria from whole human blood.

Isolation of specific cells from whole blood is important to monitor disease prognosis and diagnosis. In this study, a vibration-assisted filtration (VF) device has been developed for isolation and recovery of specific cells such as leukocytes and pathogenic bacteria from human whole blood. The VF device is composed of three layers which was fabricated using injection molding with cyclic olefin copolymer (COC) pellets consisting of: a top layer with coin-type vibration motor (Ф = 10mm), a middle plate with a 1μm or 3μm-pore filter membrane to separate of Staphylococcus aureus (S.

Attomolar detection of extracellular microRNAs released from living prostate cancer cells by a plasmonic nanowire interstice sensor.

Prostate cancer (PC) is the second leading cause of cancer death for men worldwide. The serum prostate-specific antigen level test has been widely used to screen for PC. This method, however, exhibits a high false-positive rate, leading to over-diagnosis and over-treatment of PC patients.

Fabrication of newspaper-based potentiometric platforms for flexible and disposable ion sensors.

Paper-based materials have attracted a great deal of attention in sensor applications because they are readily available, biodegradable, inexpensive, and mechanically flexible. Although paper-based sensors have been developed, but important obstacles remian, which include the retention of chemical and mechanical stabilities when paper is wetted. Herein, we develop a simple and scalable process for fabrication of newspaper-based platforms by coating of parylene C and patterning of metal layers.

High performance electrochemical glucose sensor based on three-dimensional MoS/graphene aerogel.

Two-dimensional (2D) nanosheets have been extensively explored as electrode materials for the development of high-performance electrochemical biosensors due to their unique structural characteristics. Nevertheless, 2D nanosheets suffer from sheet aggregation issues limiting the electrical conductivity of layered metal sulfides or hydroxides. Here, we report high-performance glucose biosensors based on a three-dimensional (3D) aerogel composed of interconnected 2D MoS and graphene sheet.

Surface-Modified Mesh Filter for Direct Nucleic Acid Extraction and its Application to Gene Expression Analysis.

Rapid and convenient isolation of nucleic acids (NAs) from cell lysate plays a key role for onsite gene expression analysis. Here, this study achieves one-step and efficient capture of NA directly from cell lysate by developing a cationic surface-modified mesh filter (SMF). By depositing cationic polymer via vapor-phase deposition process, strong charge interaction is introduced on the surface of the SMF to capture the negatively charged NAs.

High performance flexible pH sensor based on polyaniline nanopillar array electrode.

Flexible pH sensor technologies have attracted a great deal of attention in many applications, such as, wearable health care devices and monitors for chemical and biological processes. Here, we fabricated flexible and thin pH sensors using a two electrode configuration comprised of a polyaniline nanopillar (PAN) array working electrode and an Ag/AgCl reference electrode. In order to provide nanostructure, soft lithography using a polymeric blend was employed to create a flexible nanopillar backbone film.

Fabrication of Flexible, Redoxable, and Conductive Nanopillar Arrays with Enhanced Electrochemical Performance.

Highly ordered and flexible nanopillar arrays have received considerable interest for many applications of electrochemical devices because of their unique mechanical and structural properties. Here, we report on highly ordered polyoxometalate (POM)-doped polypyrrole (Ppy) nanopillar arrays produced by soft lithography and subsequent electrodeposition. As-prepared POM-Ppy/nanopillar films show superior electrochemical performances for pseudocapacitor and enzymeless electrochemical sensor applications and good mechanical properties, which allowed them to be easily bent and twisted.

A Monocular Vision Sensor-Based Obstacle Detection Algorithm for Autonomous Robots.

This paper presents a monocular vision sensor-based obstacle detection algorithm for autonomous robots. Each individual image pixel at the bottom region of interest is labeled as belonging either to an obstacle or the floor. While conventional methods depend on point tracking for geometric cues for obstacle detection, the proposed algorithm uses the inverse perspective mapping (IPM) method.

Polyoxometalate-grafted graphene nanohybrid for electrochemical detection of hydrogen peroxide and glucose.

The electrochemical performances of electrochemical biosensors largely depend on electrode characteristics, such as size, composition, surface area, and electron and ion conductivities. Herein, highly efficient electrocatalytic polyoxometalate (POM) was directly deposited on polymeric ionic liquid (PIL)-functionalized reduced graphene oxide (rGO) in a simple manner. The nano-sized POM with PIL functional groups was uniformly distributed on the surface of rGO sheets.

Nanopillar films with polyoxometalate-doped polyaniline for electrochemical detection of hydrogen peroxide.

Design and fabrication of electrodes is key in the development of electrochemical sensors with superior electrochemical performances. Herein, an enzymeless electrochemical sensor is developed for detection of hydrogen peroxide based on the use of highly ordered polyoxometalate (POM)-doped polyaniline (PANI) nanopillar films. The electrodeposition technique enables the entrapment of POMs into PANI during electropolymerization to produce thin coatings of POM-PANI.

Afocal optical flow sensor for reducing vertical height sensitivity in indoor robot localization and navigation.

This paper introduces a novel afocal optical flow sensor (OFS) system for odometry estimation in indoor robotic navigation. The OFS used in computer optical mouse has been adopted for mobile robots because it is not affected by wheel slippage. Vertical height variance is thought to be a dominant factor in systematic error when estimating moving distances in mobile robots driving on uneven surfaces.

High density decoration of noble metal nanoparticles on polydopamine-functionalized molybdenum disulphide.

Here, we report a highly stable colloidal suspension of nanoparticles (i.e., Pt and Au)-deposited MoS2 sheets, in which polydopamine (PD) serves as surface functional groups.

A Highly Sensitive and Reliable Strain Sensor Using a Hierarchical 3D and Ordered Network of Carbon Nanotubes.

A 3D network of single-walled carbon nanotubes embedded in poly-(dimethylsiloxane) is presented as a promising route to the fabrication of a flexible film with ordered and interconnected single-walled carbon nanotubes. This is possible using a simple transfer method of as-grown hierarchical single-walled carbon nanotubes on a Si pillar substrate. This film is used as a highly sensitive strain gauge sensor.

Multifunctional polyurethane sponge for polymerase chain reaction enhancement.

Selective filtering of target biomaterials from impurities is an important task in DNA amplification through polymerase chain reaction (PCR) enhancement and gene identification to save endangered animals and marine species. Conventional gene extraction methods require complicated steps, skilled persons, and expensive chemicals and instruments to improve DNA amplification. Herein, we proposed an alternative method for overcoming such challenges by imparting secondary functionality using commercially available polyurethane (PU) sponges and cost-effective fabrication approaches through polydopamine and polysiloxane coatings.

Ultrasonic bonding method for heterogeneous microstructures using self-balancing jig.

Perfect sealing of heterogeneous microstructures in plastic-based microfluidic devices is a significant and urgent challenge to be able to apply them in various microfluidic-based applications, including biosensing, biofiltering, chemical reactors and lab-on-a-chip. In this study we report a simple but practical and effective method to bond a microstructure-incorporated microfluidic device using an ultrasonic bonding method. The specially designed hemisphere-shaped jig, which is called a self-balancing jig, provides a free motion in all x, y, and z directions.

Scalable nanopillar arrays with layer-by-layer patterned overt and covert images.

Transferring flexible and scalable nano-pillar arrays on a variety of unconventional substrates, including fabric, paper, and metals, is achieved by a single-step replication process using UV-curable polymers. Local alteration of the contact angle on the nanopillar arrays by LBL films creates selectively hidden images. They can be revealed by the breath and used as an innovative anti-counterfeit technology.

A universal spring-probe system for reliable probing of electrochemical lab-on-a-chip devices.

For achieve sensitivity in lab-on-a-chip electrochemical detection, more reliable probing methods are required, especially for repeated measurements. Spring-probes are a promising candidate method which can replace needle-like probes and alligator clips that usually produce scratches on the surface of gold electrodes due to the strong physical contacts needed for electrochemical measurements. The superior reliability of amperometric measurements by a spring-probe system was compared with results by conventional probing methods.