Gold Probes Research Articles

Development of wireless, chipless neural stimulator by using one-port surface acoustic wave delay line and diode–capacitor interface

For the first time, a wireless and chipless neuron stimulator was developed by utilizing a surface acoustic wave (SAW) delay line, a diode–capacitor interface, a sharp metal tip, and antennas for the stimulation of neurons in the brain. The SAW delay line supersedes presently existing complex wireless transmission systems composed of a few thousands of transistors, enabling the fabrication of wireless and chipless transceiver systems. The diode–capacitor interface was used to convert AC signals to DC signals and induce stimulus pulses at a sharp metal probe. A 400 MHz RF energy was wirelessly radiated from antennas and then stimulation pulses were observed at a sharp gold probe. A ∼5 m reading distance was obtained using a 1 mW power from a network analyzer. The cycles of electromagnetic (EM) radiation from an antenna were controlled by shielding the antenna with an EM absorber. Stimulation pulses with different amplitudes and durations were successfully observed at the probe. The obtained pulses were ∼0.08 mV in amplitude and 3–10 Hz in frequency. Coupling-of-mode (COM) and SPICE modeling simulations were also used to determine the optimal structural parameters for SAW delay line and the values of passive elements. On the basis of the extracted parameters, the entire system was experimentally implemented and characterized.

Multiplex single-cell quantification of rare RNA transcripts from protoplasts in a model plant system.

Here we demonstrate multiplex and simultaneous detection of four different rare RNA species from plant, Arabidopsis thaliana, using surface-enhanced Raman spectroscopy (SERS) and gold nanoprobes at single-cell resolution. We show the applicability of nanoparticle-based Raman spectroscopic sensor to study intracellular RNA copies. First, we demonstrate that gold-nanoparticles decorated with Raman probes and carrying specific nucleic acid probe sequences can be uptaken by the protoplasts. We confirm the internalization of gold nanoprobes by transmission electron microscopy, inductively-coupled plasma-mass spectrometry and fluorescence imaging. Second, we show the utility of a SERS platform to monitor individual alternatively spliced (AS) variants and miRNA copies within single cells. Finally, the distinctive spectral features of Raman-active dyes were exploited for multiplex analysis of AtPTB2, AtDCL2, miR156a and miR172a. Furthermore, single-cell studies were validated by invitro quantification and evaluation of nanotoxicity of gold probes. Raman tag functionalized gold nanosensors yielded an approach for the tracking of rare RNAs within the protoplasts. The SERS-based approach for quantification of RNAs has the capability to be a highly sensitive, accurate and discerning method for single-cell studies including AS variants quantification and rare miRNA detection in specific plant species.

Closed-Tube PCR with Nested Serial Invasion Probe Visualization Using Gold Nanoparticles.

Detecting DNA biomarkers related to personalized medicine could improve the outcome of drug therapy. However, personalized medicine in a resource-restrained hospital is very difficult because DNA biomarker detection should be performed by well-trained staff and requires expensive laboratory facilities. We developed a gold nanoparticle-based "Tube-Lab" to enable DNA analysis in a closed tube. Gold nanoparticle-modified probes (GNPs) were used to construct an inexpensive and simple DNA sensor for signal readout. The method consists of 3 steps (template amplification, sequence identification, and GNP-based signal readout), bridged by an invasive reaction. With temperature control at each step, the 3 reactions proceed sequentially and automatically in a closed tube without any liquid transfer. We used Tube-Lab to detect different biomarkers in blood, tissue, and plasma, including US Food and Drug Administration-approved pharmacogenomic biomarkers (single nucleotide polymorphisms, somatic mutations). The combination of PCR-based template replication and invader-based signal amplification allowed detection of approximately 6 copies of input DNA and the selective pick up 0.1% mutants from large amounts of background DNA. This method highly discriminated polymorphisms and somatic mutations from clinical samples and allowed a "liquid biopsy" assay with the naked eye. Tube-Lab provides a promising and cost-effective approach for DNA biomarker analysis, including polymorphisms and somatic mutations from blood DNA, tissue DNA, or circulating tumor DNA in plasma, which are critical for personalized medicine.

Thermal evaporated Copper Iodide (CuI) thin films: A note on the disorder evaluated through the temperature dependent electrical properties

Copper Iodide (CuI) thin films are p-type transparent conductors. In the present investigation, the physical properties of thermally evaporated (at 300K) γ-phase copper iodide (CuI) thin films (of thickness 120nm) prepared on the quartz substrates have been reported. The grain size (from SEM measurements) is ~ 80nm. The (direct) optical band gap of CuI is 3.0eV; the films show >70% transmission in the wavelength range 550–1000nm and have low electrical resistance 72 mΩ cm. The Photo-luminescence spectra (with excitation wavelength 325nm) shows a violet emission at ~ 409.4nm (corresponds to the near band edge emission) and a shoulder peak centered at 417.4nm (indicates the trap level near to the valence band edge induced by Iodine). The Hall mobility and carrier density of holes (from room temperature Hall measurements) in CuI thin films calculated are 1.46cm2/V/s and 5.8×1019cm−3 respectively. The disorder in the CuI thin films is evaluated by the temperature dependent (20–300K) electrical resistivity measurements. The surface work-function of the CuI thin films measured by Kelvin probe technique; a non-destructive and sensitive surface analytical technique, is 4.71eV (with reference to the gold probe).

Apertureless Near-Field Scanning Probes Based on Graphene Plasmonics

We present a novel approach in designing high-throughput high-resolution apertureless near-field scanning probes with enhanced nanofocusing based on graphene plasmonics. Extremely localized plasmons on graphene are mingled with nanofocusing of surface plasmon polaritons to confine and steer the plasmon waves into the apex of a near-field scanning optical microscopy tip. The Fermi level, localized emission sites on graphene, and the angle of excitation play a critical role in exciting graphene surface plasmons on the lateral walls of the designed conical probes. The optimized probes feature full-width at half-maximum (FWHM) around 25 nm, which is at least two times smaller than conventional metallic plasmonic tips. The near-field electromagnetic properties of the designed probes are characterized in detail and compared to the conventional single-aperture and typical apertureless metallic plasmonic (silver and gold) probes. Over three orders of magnitude electric field enhancement compared to metallic probes on SiO 2 substrate has been achieved.

Gold Nanoparticle-Based Probe for Colorimetric Detection of Copper Ions.

A new ligand 10-mercaptodecyl-1-iminodiacetic acid (MDIA) was synthesized and used to modify gold nanoparticles to provide a simple assay to repeatedly sense Cu²⁺ in the solution at room temperature. This functionalized gold nanosensor was applied for the detection of Cu²⁺ in water samples with sensitivity and simplicity. The chelation/aggregation process is reversible via addition of a strong metal ion chelator such as EDTA. This simple and fast colorimetric sensor is important in the application of copper ion detection in water quality during the emergency and early warning monitoring.

Atomistic simulations of contact area and conductance at nanoscale interfaces.

Atomistic simulations were used to study conductance across the interface between a nanoscale gold probe and a graphite surface with a step edge. Conductance on the graphite terrace was observed to increase with load and be approximately proportional to contact area calculated from the positions of atoms in the interface. The relationship between area and conductance was further explored by varying the position of the contact relative to the location of the graphite step edge. These simulations reproduced a previously-reported current dip at step edges measured experimentally and the trend was explained by changes in both contact area and the distribution of distances between atoms in the interface. The novel approach reported here provides a foundation for future studies of the fundamental relationships between conductance, load and surface topography at the atomic scale.

Peptide engineered microcantilevers for selective chemical force microscopy and monitoring of nanoparticle capture.

Engineered peptides capable of binding to silica have been used to provide contrast in chemical force microscopy and tested for their capacity to selectively capture silica nanoparticles (NPs). Gold coated atomic force microscopy (AFM) microcantilevers with integrated tips and colloidal probes were functionalized with engineered peptides through a thiol group of a terminal cysteine which was linked via a glycine trimer to a 12-mer binding sequence. The functionalized probes demonstrated a significantly increased binding force on silicon oxide areas of a gold-patterned silicon wafer, whereas plain gold probes, and those functionalized with a random permutation of the silica binding peptide motif or an all-histidine sequence displayed similar adhesion forces to gold and silicon oxide. As the functionalized probes also allowed contact mode imaging subsequently to the adhesion mapping, also the associated friction contrast was measured and found to be similar to the adhesion contrast. Furthermore, the adsorption of silica NPs onto planar gold surfaces functionalized in the same manner was observed to be selective. Notably, the surface coverage with silica NPs was found to decrease with increasing pH, implying the importance of electrostatic interactions between the peptide and the NPs. Finally, the adsorption of silica NPs was monitored via the decrease in fundamental resonance frequency of an AFM microcantilever functionalized with silica binding peptides.

Benzothiazole-Based Neutral Ratiometric Fluorescence Sensor for Amyloid Fibrils.

Early detection of amyloid fibrils is very important for the timely diagnosis of several neurological diseases. Thioflavin-T (ThT) is a gold standard fluorescent probe for amyloid fibrils and has been used for the last few decades. However, due to its positive charge, ThT is incapable of crossing the blood-brain barrier and cannot be used for in vivo imaging of fibrils. In the present work, we synthesized a neutral ThT derivative, 2-[2'-Me,4'-(dimethylamino)phenyl]benzothiazole (2Me-DABT), which showed a strong affinity towards the amyloid fibrils. On association with the amyloid fibrils, 2Me-DABT not only showed a large increase in its emission intensity, but also, unlike ThT, a large blueshift in its emission spectrum was observed. Thus, unlike ThT, 2Me-DABT is a potential candidate for the ratiometric sensor of the amyloid fibrils. Detailed photophysical properties of 2Me-DABT in amyloid fibrils and different solvent media were studied to understand its sensory activity. Fluorescence resonance energy transfer (FRET) studies suggested that the sites of localization for ThT and 2Me-DABT in amyloid fibrils are not same and their average distance of separation in amyloid fibrils was determined. The experimental data was nicely supported by molecular docking studies, which confirmed the binding of 2Me-DABT in the inner core of the amyloid fibrils.

A “Shocking” Cause of Biliary Obstruction and Cholangitis: Cauterization of a Bleeding Duodenal Ulcer

Introduction: Acute cholangitis can occur in the setting of biliary obstruction. Common causes include choledocholithiasis, bile duct instrumentation, benign biliary stenosis and malignant biliary obstruction. We describe a rare case of transient biliary obstruction and cholangitis following cauterization of a bleeding peptic ulcer. Presentation: A 75-year-old male with a recent admission for unstable angina requiring stenting and initiation of dual anti-platelet therapy presented with a five-day history of melena. He had a history of peptic ulcer disease complicated by hemorrhage and gastric outlet obstruction. His hemoglobin and vitals were stable at admission and he was started on a proton pump inhibitor. Hospital Course: EGD revealed an ulcer scar with a bleeding vessel in the duodenal bulb. The vessel was injected with 2 mls of 1:10000 epinephrine solution and cauterized using a 7F Boston Scientific Gold Probe. Several hours after the procedure, the patient experienced abdominal discomfort followed by fevers and chills. His labs were consistent with biliary obstruction, with significant hyperbilirubinemia and transaminitis. He was started on broad-spectrum antibiotics for cholangitis. CT abdomen showed moderate intrahepatic biliary ductal dilation and common bile duct dilation to 12mm with abrupt truncation of the distal common bile duct. ERCP was attempted but could not be completed due to the presence of a significant peptic ulcer stricture in the post-bulbar area. Dilation was deferred due to his anti-platelet therapy. MRCP also showed intrahepatic biliary duct and common bile duct dilation, enhancement of the distal common bile duct consistent with early cholangitis, and duodenal bulb edema related to cauterization. The patient remained afebrile and his liver function tests improved without intervention, so alternate methods of biliary drainage were deferred. He was discharged with antibiotics. His labs normalized after one month. Discussion: Cholangitis can have adverse outcomes and typically requires definitive management with biliary drainage. Our case highlights a rare scenario of transient biliary obstruction and cholangitis due to cauterization in the duodenal bulb. The patient's clinical improvement was likely related to resolution of his duodenal edema and did not require biliary drainage. Biliary obstruction and cholangitis should be considered as potential complications of cauterization in duodenal peptic ulcer disease.

Gastrointestinal Bleeding from a T-fastener

Introduction: A gastrostomy tube provides nutritional access for individuals who do not have the ability to swallow or are at risk of aspiration. When gastrostomy tubes are placed by radiologists T-fasteners (TFas) are often used to perform gastropexy, a method of approximating the gastric and abdominal walls. Tfas can sometimes erode through the abdominal or gastric walls leading to GI bleeding. Case report: A 72 year old female with history of dysphagia and PEG tube feeding secondary to chronic inflammatory demyelinating polyneuropathy presented with melena. She underwent CT angiography and a bleeding vessel within a pseudoaneurysm in the abdominal wall was located. Embolization of the source vessel stopped the bleeding and she was discharged. She was readmitted after a week with recurrent melena and angiography again revealed the pseudoaneurysm with a bleeding vessel but this time failed to control bleeding with embolization. EGD revealed a large clot at the site of the internal balloon of the gastrostomy tube. The clot was dislodged revealing a bleeding vessel with Tfas (Figure 1). The wire attaching the two ends of the Tfas was running through the pseudoaneurysm and the visible vessel. On examination of the external abdominal wall the Tfas wires were not visible, as they had migrated within the abdominal wall. The PEG tube was pushed aside and the Tfas were mobilized using forceps. Using hot snare forceps the wire was cut and the Tfas were removed. Gold probe cautery was applied to treat the bleeding vessel and then the PEG tube was repositioned back to its original place (Figure 2). The patient subsequently had no further GI blood loss and was discharged.Figure 1Figure 2Discussion: The use of Tfas serves to assist in safe and appropriate placement of a gastrostomy tubes, but can lead to infections or fistula formation. Rarely bleeding due to Tfas can occur, and in our case the Tfas buried into a pseudoaneurysm within the gastric wall causing bleeding. Bleeding from gastrostomy sites is most commonly secondary to ostomy incision site related bleeding, but this case highlights the need to consider bleeding from buried Tfas within pseudoaneurysms that have exposed vessels within the gastric lumen. We report use of a hot snare forceps to cut the wire attaching the ends of the Tfas and then removing each of the metallic ends separately using a grasping forceps. The underlying vessel can then be ablated to prevent further blood loss.

Submitted, Not Presented: Clinical Vignettes/Case Reports - Small Intestine/Unclassified.

Hemangiomas of the small bowel are a rare phenomenon and usually present with gastrointestinal bleeding. They are defined as masses of capillaries and blood-filled endothelial-line spaces that rarely manifest in the small intestines. Most of them are symptomatic until they present with bleeding and anemia; and less commonly can cause intestinal obstruction, intussusception or perforation. Intestinal bleeding can be acute with severe, life threatening blood loss, or chronic with anemia. Initial work up includes upper and lower gastrointestinal endoscopy, barium contrast study and computed tomography (CT) scans. Further evaluation includes video capsule endoscopy, and deep enteroscopy. We present a case of a 59 year-old male with dizziness, fatigue and melena. He endorsed a history of blood in stools for the past eight months. The patient was not taking NSAIDs or on anticoagulation medications. In the two days before admission, his episodes of black stools have considerably increased. Recent GI work up included a normal esophagogastroduodenoscopy (EGD), anterograde enteroscopy to proximal ileum showing no acute pathology, colonoscopy which revealed small nonbleeding diverticula in the sigmoid colon, and video capsule endoscopy which showed evidence of bleeding in the mid-small bowel. The patient's vitals were stable and he was not orthostatic. Physical exam was unremarkable, rectal exam showed melena, laboratory studies revealed a drop of 2 grams of hemoglobin to 9 g/dL. Repeat video capsule endoscopy again showed evidence of active bleeding in mid-small bowel with an area of questionable ulceration versus ulcerated mass. CT enterography was unremarkable with no evidence of abnormal mass. The patient underwent antegrade single balloon enteroscopy which revealed a single 1-2 cm. vascular lesion suspicious for hemangioma that was actively oozing from a punctuate lesion on the surface. To control bleeding, initially a Gold Probe was employed that slowed but did not stop bleeding. An argon beam coagulator, set at 20 watts, was then use with complete control of bleeding. This area was tattooed proximally with a sclerotherapy needle using india ink. The patient's hemoglobin stabilized and melena resolved after procedure and he was discharged home. This case illustrates successful endoscopic therapy of an actively bleeding hemangioma at the time of deep enteroscopy with the single balloon enteroscope.

Utilizing Gold Nanoparticle Probes to Visually Detect DNA Methylation.

The surface plasmon resonance (SPR) effect endows gold nanoparticles (GNPs) with the ability to visualize biomolecules. In the present study, we designed and constructed a GNP probe to allow the semi-quantitative analysis of methylated tumor suppressor genes in cultured cells. To construct the probe, the GNP surfaces were coated with single-stranded DNA (ssDNA) by forming Au–S bonds. The ssDNA contains a thiolated 5′-end, a regulatory domain of 12 adenine nucleotides, and a functional domain with absolute pairing with methylated p16 sequence (Met-p16). The probe, paired with Met-p16, clearly changed the color of aggregating GNPs probe in 5 mol/L NaCl solution. Utilizing the probe, p16 gene methylation in HCT116 cells was semi-quantified. Further, the methylation of E-cadherin, p15, and p16 gene in Caco2, HepG2, and HCT116 cell lines were detected by the corresponding probes, constructed with three domains. This simple and cost-effective method was useful for the diagnosis of DNA methylation-related diseases.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1487-5) contains supplementary material, which is available to authorized users.

Detection of Helicobacter Pylori Genome with an Optical Biosensor Based on Hybridization of Urease Gene with a Gold Nanoparticles-Labeled Probe

A novel optics-based nanobiosensor for sensitive determination of the Helicobacter pylori genome using a gold nanoparticles (AuNPs)-labeled probe is reported. Two specific thiol-modified capture and signal probes were designed based on a single-stranded complementary DNA (cDNA) region of the urease gene. The capture probe was immobilized on AuNPs, which were previously immobilized on an APTES-activated glass, and the signal probe was conjugated to different AuNPs as well. The presence of the cDNA in the reaction mixture led to the hybridization of the AuNPs-labeled capture probe and the signal probe with the cDNA, and consequently the optical density of the reaction mixture (AuNPs) was reduced proportionally to the cDNA concentration. The limit of detection was measured at 0.5 nM.

Gold nanoparticle-based multivalent carbohydrate probes: selective photoaffinity labeling of carbohydrate-binding proteins.

Multivalent carbohydrate photoaffinity probes were developed based on gold nanoparticles (AuNPs) to provide a streamlined approach toward identification of carbohydrate-binding proteins. By using AuNPs as scaffolds, a carbohydrate ligand and a photoreactive group could be readily assembled on a probe in a modular fashion, which greatly accelerated the process of optimizing the probe design. The novel AuNP-based probes serve dual functions by facilitating photoaffinity labeling and by directly enriching the crosslinked proteins by centrifugation. We demonstrated that their ability to enhance the affinity and to stringently remove nonspecific proteins allowed selective photoaffinity labeling and isolation of a low affinity carbohydrate-binding protein in cell lysate.

Gold nanoclusters-based dual-emission ratiometric fluorescence probe for monitoring protein kinase

A novel and sensitive ratiometric fluorescent assay for monitoring kinase activity based on carboxypeptidase Y (CPY) digestion by using Au nanoclusters (AuNCs) and CdSe/ZnS QDs@SiO2 as the dual-emission nanoparticles is developed. This approach can not only sensitively monitor the kinase activity with affording built-in correction which avoids environmental interferences, but also realize visual detection. Under optimal conditions, a linear relationship between the fluorescence intensity ratio (I415/I630) of CdSe/ZnS QDs@SiO2@peptide-AuNCs and the protein kinase A (PKA) concentration in a range of 0.01 to 40UmL−1 with a detection limit of 0.004UmL−1 (3σ) is obtained. The feasibility of this CdSe/ZnS QDs@SiO2@peptide-AuNCs-based ratiometric sensor has been further demonstrated by assessment of kinase inhibition by ellagic acid in cell lysates. The IC50 value (inhibitor concentration producing 50% inhibition) for ellagic acid is estimated to be 0.08μM. The detection of other enzymes can also be realized with precise design of the peptide substrate sequences. The present assay is universal and visual for kinase assay and promises potential application in kinase-related biochemical fundamental research and inhibitor screening.

A Case That Breaks the Mold: Gastric Aspergillosis as a Cause of Recurrent Bleeding

Invasive gastric aspergillosis is a rare cause of recurrent bleeding in immunocompromised patients. A 44-year-old man presented with severe sepsis from multi-lobar pneumonia requiring intubation, pressors, and dialysis. He was on IV methylprednisolone 40mg every 6 hours without PPI. On hospital day 9, he developed massive hematemesis. Following transfusion, esophagogastroduodenoscopy (EGD) revealed multiple ulcerations (largest 2 cm) in the gastric body along lesser and greater curves extending into the antrum. Several were oozing or had a visible vessel and were treated with epinephrine injection, gold probe cautery, and clipping. A PPI drip was started. Abdominal angiogram did not reveal extravasation of blood. However, over the next 5 days, he developed recurrent bleeding with 3 additional endoscopies with the same findings and interventions. After each EGD, hemostasis was achieved for 2-3 days but recurred, warranting repeat EGD. Due to lack of response to endoscopic therapy, he underwent total gastrectomy with Roux-en-Y esophagojejunostomy. Gastric ulcer biopsies showed fungal hyphae on Grocott's methenamine silver (GMS) stain. Immunostains were negative for Helicobacter pylori, CMV, and HSV. The gastrectomy specimen showed multiple superficial ulcerations throughout the stomach with pseudohyphal elements. Sputum cultures grew Aspergillus fumigatus and Aspergillus flavus. Therapy with liposomal amphotericin B and intravenous isavuconazole was begun and subsequently changed to oral voriconazole, with plans to continue for at least 3 months. He tested negative for causes of immune deficiency. Invasive aspergillosis typically develops in immunocompromised patients and carries a 50-60% mortality. Most commonly, invasive aspergillosis involves the lungs and rarely the gastrointestinal tract. The 6 reported cases of gastric aspergillosis presented as either ulcers or transmural necrosis. Most had previous chemotherapy or systemic steroid exposure. Four showed deep invasion transmurally or into the blood vessels; however, one case had pulmonary Aspergillus and superficial colonization of the gastric ulcers. Voriconazole is the recommended treatment for invasive aspergillosis and usually requires months to years of treatment. This individual worked in a nursery potting plants, which was likely his exposure. We believe he presented with pulmonary aspergillosis, became immunocompromised from the steroids, and this resulted in secondary infection of the stomach.

Volumetric laser endomicroscopy in Barrett's esophagus: a feasibility study on histological correlation.

Volumetric laser endomicroscopy (VLE) is a novel balloon-based optical coherence tomography (OCT) imaging technique that may improve detection of early neoplasia in Barrett's esophagus (BE). Most OCT studies lack a direct correlation between histology and OCT images. The aim is to investigate the optimal approach for achieving one-to-one correlation of ex-vivo VLE images of endoscopic resection (ER) specimens with histology. BE patients with and without early neoplasia underwent ER after delineating areas with electrocoagulation markers (ECM). After ER, specimens underwent additional ex-vivo marking with several different markers (ink, pin, Gold Probe) followed by ex-vivo VLE scanning. ER specimens were carefully sectioned into tissue blocks guided by the markers. Histology and VLE slides were considered a match if ≥ 2 markers were visible on both modalities and mucosal patterns aside from these markers matched on both histology and VLE. From 16 ER specimens 120 tissue blocks were sectioned of which 23 contained multiple markers. Fourteen histology-VLE matches were identified. ECMs and ink markers proved to be the most effective combination for matching. The last 6/16 ER specimens yielded 9/14 matches, demonstrating a learning curve due to methodological improvements in marker placement and tissue block sectioning. One-to-one correlation of VLE and histology is complex but feasible. The groundwork laid in this study will provide high-quality histology-VLE correlations that will allow further research on VLE features of early neoplasia in BE.

Solid-phase pink-to-purple chromatic strips utilizing gold probes and nanofibrous membranes combined system for lead (II) assaying

Creating a sensitive and selective method that can provide simple, practical, and high throughput determination of lead ions (Pb2+) has proved extremely challenging. This work responds to this challenge by designing, fabricating, and evaluating a portable sensor strip for naked-eye chromatic assaying of trace amount of Pb2+. The sensor design is then realized utilizing electrospun nylon-6/polyvinylidene fluoride (N6/PVDF) nanofibers/nets (NFN) membranes assemble L-glutathione-conjugated Au nanoparticle probes (Au@GSH), which can aggregate to trigger a vivid color change of pink to purple upon incubation with Pb2+. Benefiting from large surface areas, high porosity, and Steiner tree networks structure of the NFN membranes, the strips exhibited excellent stability, rapid response (10min), wide detection range (10–500μg/dL) and low naked-eye detection limit of 10μg/dL. Additionally, the sensing responses are visualized quantitatively by employing a chromatic framework that translates measured spectra into numeric color values directly related to color perception. Furthermore, the NFN-based strip displayed excellent selectivity to other possible metal cations. The result clearly demonstrated that this is a promising sensing system which could act as a first step toward remediation of lead poisoning in future.

PWE-069 Comparison Of Microwave With Monopolar And Bipolar Coagulation In A Porcine Model

IntroductionIntra-procedural bleeding is considered an immediate serious adverse event and a major concern for the endoscopist and the patient. Current endoscopic devices utilise monopolar or bipolar energy to treat acute...