One dimensional polyaniline nanowire is an electrically conducting polymer that can be used as an active layer for sensors whose conductivity change can be used to detect chemical or biological species. In this review, the basic properties of polyaniline nanowires including chemical structures, redox chemistry, and method of synthesis are discussed. A comprehensive literature survey on chemiresistive/conductometric sensors based on polyaniline nanowires is presented and recent developments in polyaniline nanowire-based sensors are summarized. Finally, the current limitations and the future prospect of polyaniline nanowires are discussed.

The proximal and distal metaphyseal areas of the tibia have a rich extraosseous blood supply provided primarily by branches of the ATA and the PTA. Open plating of the medial aspect of the distal tibia caused a greater disruption of this extraosseous blood supply than did percutaneously applied plates. Disruption of these extraosseous vessels following fracture and subsequent operative stabilization may slow healing and increase the risk of delayed union and nonunion. These findings support current efforts to develop less invasive methods and implants for operative stabilization of distal tibia fractures.

Neurotransmitters are chemicals that act as messengers in the synaptic transmission process. They are essential for human health and any imbalance in their activities can cause serious mental disorders such as Parkinson's disease, schizophrenia, and Alzheimer's disease. Hence, monitoring the concentrations of various neurotransmitters is of great importance in studying and diagnosing such mental illnesses. Recently, many researchers have explored the use of unique materials for developing biosensors for both in vivo and ex vivo neurotransmitter detection. A combination of nanomaterials, polymers, and biomolecules were incorporated to implement such sensor devices. For in vivo detection, electrochemical sensing has been commonly applied, with fast-scan cyclic voltammetry being the most promising technique to date, due to the advantages such as easy miniaturization, simple device architecture, and high sensitivity. However, the main challenges for in vivo electrochemical neurotransmitter sensors are limited target selectivity, large background signal and noise, and device fouling and degradation over time. Therefore, achieving simultaneous detection of multiple neurotransmitters in real time with long-term stability remains the focus of research. The purpose of this review paper is to summarize the recently developed sensing techniques with the focus on neurotransmitters as the target analyte, and to discuss the outlook of simultaneous detection of multiple neurotransmitter species. This paper is organized as follows: firstly, the common materials used for developing neurotransmitter sensors are discussed. Secondly, several sensor surface modification approaches to enhance sensing performance are reviewed. Finally, we discuss recent developments in the simultaneous detection capability of multiple neurotransmitters.

This paper presents a fully inkjet-printed electrochemical sensor on paper which consists of carbon nanotube-printed working, reference, and counter electrodes. The proposed technique aims at low-cost and disposable paper-based electrochemical sensors. First, a carbon nanotube (CNT) ink was inkjet-printed directly on paper, forming a conductive network. Additionally, a hydrophobic barrier was patterned on paper to limit the absorption of liquid to the designed area. The inkjet printing method allows for rapid patterning of electrodes on paper, resulting in a simple and effective electrochemical sensor. The sheet resistance of the CNT-printed paper was as low as 1 k / after 33 prints. A potential step voltammetry method was applied to determine the concentration of the analytes, iron ion (Fe 2+ ) and dopamine (DA), with linear ranges of 10 μM-200 μM and 10 μM-100 μM, respectively. The reported approach for a fully inkjet-printed electrochemical sensor is easy and cheap, and it has a potential for simple and rapid paper-based point-of-care diagnostics. Paper-based chemical and biological sensors have become attractive in recent years due to their facile fabrication, simplicity of use, and the ability of paper to easily absorb and retain liquid.1,2 Recent developments incorporate hydrophobic barriers, 3,4 microfluidic channels 5 and stacking layers for sensing purposes. 6 Among other characteristics, paper is a low cost material, readily available, and is also flexible.In order to develop a paper-based sensor, various materials must be patterned on paper for sensing purposes.7 Therefore a quick and easy method to pattern such materials is the subject of great interest. In connection with printed electronics technology, various printing methods exist for patterning conductive materials on thin substrates. 8Among them, inkjet printing has much interest due to many advantages such as automated printing process, mass producibility, and uniform deposition of materials.9 Here, we are interested in utilizing the inkjet printing technology for the development of a paper-based electrochemical sensor.Printing methods have been applied for chemical sensors in a number of ways; however, since further steps were required in order to build a complete device, it is desirable to develop a simpler printing process. For example, inkjet printing was used to print dissolvable materials in order to pattern hydrophobic areas, 10 where it was necessary to dip coat the paper and clean the dissolved material afterwards. In another instance, inkjet printing of metal nanoparticles was performed with an additional sintering step.11 Thus, a simpler one step process to develop a paper-based sensing device is necessary which should be easy and cheap to fabricate.Although paper based analytical devices have been greatly advanced, a simple method of fabrication coupled with reliable detection method is still needed. Our approach targets the fabrication issue by integrating all the fabrication steps into a single method of inkjet printing. This can...

Aptamers are oligonucleotides or peptides that are selected from a pool of random sequences that exhibit high affinity toward a specific biomolecular species of interest. Therefore, they are ideal for use as recognition elements and ligands for binding to the target. In recent years, aptamers have gained a great deal of attention in the field of biosensing as the next-generation target receptors that could potentially replace the functions of antibodies. Consequently, it is increasingly becoming popular to integrate aptamers into a variety of sensing platforms to enhance specificity and selectivity in analyte detection. Simultaneously, as the fields of lab-on-a-chip (LOC) technology, point-of-care (POC) diagnostics, and personal medicine become topics of great interest, integration of such aptamer-based sensors with LOC devices are showing promising results as evidenced by the recent growth of literature in this area. The focus of this review article is to highlight the recent progress in aptamer-based biosensor development with emphasis on the integration between aptamers and the various forms of LOC devices including microfluidic chips and paper-based microfluidics. As aptamers are extremely versatile in terms of their utilization in different detection principles, a broad range of techniques are covered including electrochemical, optical, colorimetric, and gravimetric sensing as well as surface acoustics waves and transistor-based detection.

A water-based carbon nanotube ink for inkjet printing was prepared by dispersing single-walled carbon nanotubes (SWCNT) with sodium n-dodecyl sulfate (SDS), an anionic surfactant. A standard Hewlett-Packard (HP) inkjet printer was employed to deposit the carbon nanotube ink onto a transparency film in order to form conductive electrodes. A sheet resistance as low as 132 / was obtained for the carbon nanotube electrodes, which is one of the lowest values ever reported. Using inkjet-printed carbon nanotubes and screen-printed silver epoxy, a cheap, flexible, and disposable electrochemical sensor was fabricated and characterized using cyclic voltammetry (CV). The results of these tests indicate that the fully printed device behaves as a reliable electrochemical ionic sensor. Furthermore, the demonstrations presented in this work show that inkjet-printed carbon nanotube electrodes are very promising and have potential for use in many different applications.

Correction of sagittal and coronal deformity is important in the treatment of spinal deformity. A significant association was found between outcomes and radiographic correction of coronal and/or sagittal deformity if postoperative sagittal lordosis was >25 degrees and if postoperative plumb coronal alignment was <2.5 cm. Therefore, these radiographic parameters should be the goal of a spinal osteotomy. The surgery has a relatively high complication rate.

Continuous and real-time detection of protein biomarker using a microfluidic graphene-based transistor functionalized with thrombin-binding aptamers.