Nitrite determination in food using electrochemical sensor based on self-assembled MWCNTs/AuNPs/poly-melamine nanocomposite.

A nanocomposite of multi-walled carbon nanotubes/gold nanoparticles/poly-melamine (MWCNTs/AuNPs/PM) was designed using layer-by-layer self-assembled method on glassy carbon electrode (GCE) by electrochemical deposition to construct an electrochemical sensor for sensitive detection of nitrite. First, a layer of MWCNTs was modified on electrode, and then gold nanoparticles and melamine were in-situ polymerized onto MWCNTs through self-assembled technique to form GCE/MWCNTs/AuNPs/PM. MWCNTs have large specific surface area, which increased the number of gold nanoparticles deposited on MWCNTs.

Bisphenol A detection based on nano gold-doped molecular imprinting electrochemical sensor with enhanced sensitivity.

A facile electrochemical sensor based on nano gold-doped molecularly imprinted polymer (MIP) was proposed to realize the selective detection of bisphenol A (BPA) with enhanced sensitivity. Initially, gold-doped MIP (Au@MIP) film was constructed by electropolymerizing p-aminobenzoic acid (PABA) and BPA with in situ gold reduction to distribute gold nanoparticles nearby the imprinted cavities. Subsequently, the template molecules were further extracted from the polymer film, then the MIP could rebind with the template molecules to achieve specific detection of BPA.

Electrochemical Self-Assembled Gold Nanoparticle SERS Substrate Coupled with Diazotization for Sensitive Detection of Nitrite.

The accurate determination of nitrite in food samples is of great significance for ensuring people's health and safety. Herein, a rapid and low-cost detection method was developed for highly sensitive and selective detection of nitrite based on a surface-enhanced Raman scattering (SERS) sensor combined with electrochemical technology and diazo reaction. In this work, a gold nanoparticle (AuNP)/indium tin oxide (ITO) chip as a superior SERS substrate was obtained by electrochemical self-assembled AuNPs on ITO with the advantages of good uniformity, high reproducibility, and long-time stability.

Development of Highly Sensitive Immunosensor for Detection of Based on AuPdPt Trimetallic Nanoparticles Functionalized Nanocomposite.

The rapid and sensitive detection of () is essential to ensure food safety and protect humans from foodborne diseases. In this study, a sensitive and facile electrochemical immunosensor using AuPdPt trimetallic nanoparticles functionalized multi-walled carbon nanotubes (MWCNTs-AuPdPt) as the signal amplification platform was designed for the label-free detection of . The nanocomposite of MWCNTs-AuPdPt was prepared by an in situ growth method of loading AuPdPt trimetallic nanoparticles on the surface of MWCNTs.

Quantitative analysis of colony number in mouldy wheat based on near infrared spectroscopy combined with colorimetric sensor.

Current work presented a novel method based on colorimetric sensor (CS) combined with visible/near-infrared spectroscopy (VNIRs) for the detection of volatile markers in wheat infected by Aspergillus glaucus. Wheat samples with different mouldy degree was cultivated for backup under temperature of 25-28 °C in incubator. The total colony number was determined by flat colony counting method.

Electrochemical immunosensor based on self-assembled gold nanorods for label-free and sensitive determination of Staphylococcus aureus.

An electrochemical immunosensor based on self-assembled gold nanorods on glassy carbon electrode was developed for label-free and sensitive detection of Staphylococcus aureus (S. aureus). The gold nanorods were firstly assembled on the electrode surface by using poly-(diallyldimethylammonium chloride) (PDDA) and poly-(styrenesulfonate) (PSS) as the linkers, followed by the functionlization of anti-S.

Simple electrochemical sensing for mercury ions in dairy product using optimal Cu-based metal-organic frameworks as signal reporting.

A convenient sensor is developed for electrochemical assay of Hg in dairy product using the optimal Cu-based metal-organic frameworks (Cu-MOFs) as signal reporting. Benefiting from specific recognition between Hg and thymine (T)-rich DNA strands, the interferences of milk matrices are effectively eliminated, thereby greatly improving the accuracy of test results. Moreover, the suitable Cu-MOFs offer an efficient carrier for probe design, and the contained Cu ions could be directly detected to output electrochemical signal of Hg presence without labor- or time-intensive operations.

Structure-Switching Electrochemical Aptasensor for Single-Step and Specific Detection of Trace Mercury in Dairy Products.

A reagentless and single-step electrochemical aptasensor with separation-free fashion and rapid response is developed for the Hg assay in dairy products. Herein, the sensing strategy is established on Hg-induced structural transition of the methylene-blue-tagged single-stranded DNA (ssDNA) from a flexible manner to rigid hairpin-shaped double-stranded DNA (dsDNA), generating an improved peak current for the Hg assay with a detection limit of 0.62 fM.

Trace Urine Albumin and Mortality: Kangbuk Samsung Health Study.

Background/aims: The importance of a trace albumin on the urine dipstick test is not well known and is frequently disregarded in clinical practice. The aim of this study is to investigate the role of trace albuminuria in predicting all-cause mortality in Korean adults.

Methods: In this retrospective cohort study, we analyzed 347,938 Korean adults who underwent urine dipstick test from 2002 to 2012 in a health examination program.

A homogeneous assay for highly sensitive detection of CaMV35S promoter in transgenic soybean by förster resonance energy transfer between nitrogen-doped graphene quantum dots and Ag nanoparticles.

In this work, a novel homogeneous assay for DNA quantitative analysis based on förster resonance energy transfer (FRET) was developed for cauliflwer mosaic virus 35s (CaMV35S) promoter of transgenic soybean detection. The homogenous FRET of fluorescence signal was fabricated by DNA hybridization with probe modified nitrogen-doped graphene quantum dots (NGQDs) and silver nanoparticles (AgNPs), which acted the donor-acceptor pairs for the first time. The highly efficient FRET and unique properties of the NGQDs made the proposed FRET system as a functionalized detection platform for labelling of DNA.

Photoelectrochemical CaMV35S biosensor for discriminating transgenic from non-transgenic soybean based on SiO@CdTe quantum dots core-shell nanoparticles as signal indicators.

A methodology for detection of the Cauliflower Mosaic Virus 35S(CaMV35S) promoter was developed to distinguish transgenic from non-transgenic soybean samples by using photoelectrochemical (PEC) biosensor. In this PEC biosensing system, the as-prepared gold nanoparticles-reduced graphene oxide acted as a nanocarrier to immobilize the thiol-functional probe (probe1), and the SiO@CdTe quantum dots (QDs) core-shell nanoparticles tagged with the amino-functional probe (probe2) acted as signal indicators, respectively. In the presence of target DNA (tDNA) of CaMV35S, the binding of tDNA with probe1 and probe2 through the high specific DNA hybridization led to the fabrication of sandwich structure, and thus the high loading of the signal indicators SiO@CdTe QDs at the electrode surface, which increased the PEC signal.

Primary squamous cell carcinoma of the liver: a case report.

Primary squamous cell carcinoma (SCC) of the liver is very rare, and few cases have been reported in Korea. Primary SCC of the liver is known to be associated with hepatic cysts and intrahepatic stones. A 71-year-old male was admitted to our hospital, and a abdominal computed tomography scan revealed a 10 × 6 cm mass in the liver.

Optimized dendrimer-encapsulated gold nanoparticles and enhanced carbon nanotube nanoprobes for amplified electrochemical immunoassay of E. coli in dairy product based on enzymatically induced deposition of polyaniline.

A highly sensitive immunosensor was reported for Escherichia coli assay in dairy product based on electrochemical measurement of polyaniline (PAn) that was catalytically deposited by horseradish peroxidase (HRP) labels. Herein, the immunosensor was developed by using poly(amidoamine) dendrimer-encapsulated gold nanoparticles (PAMAM(Au)) as sensing platform. Importantly, the optimal HAuCl4/PAMAM ratio was investigated to design the efficient PAMAM(Au) nanocomposites.

Change in fatty liver status and 5-year risk of incident metabolic syndrome: a retrospective cohort study.

Introduction: Fatty liver is associated with metabolic syndrome (MetS) but it may also occur without MetS. Whether resolution of fatty liver in the general population affects risk of MetS is unknown. Our aim was to determine whether a change in fatty liver status (either the development of new fatty liver or the resolution of existing fatty liver) would modify the risk of de novo MetS.

The Relationship between 10-Year Cardiovascular Risk Calculated Using the Pooled Cohort Equation and the Severity of Non-Alcoholic Fatty Liver Disease.

Background: We investigated the association between the severity of non-alcoholic fatty liver disease (NAFLD) and the estimated 10-year risk of cardiovascular disease (CVD) calculated by Pooled Cohort Equation (PCE) and Framingham risk score (FRS).

Methods: A total of 15,913 participants (mean age, 46.3 years) in a health screening program were selected for analysis.

Metabolic Health Is More Important than Obesity in the Development of Nonalcoholic Fatty Liver Disease: A 4-Year Retrospective Study.

Background: The aim of this study is to compare the risk for future development of nonalcoholic fatty liver disease (NAFLD) according to different status of metabolic health and obesity.

Methods: A total of 3,045 subjects without NAFLD and diabetes at baseline were followed for 4 years. Subjects were categorized into four groups according to the following baseline metabolic health and obesity statuses: metabolically healthy, non-obese (MHNO); metabolically healthy, obese (MHO); metabolically unhealthy, non-obese (MUHNO); and metabolically unhealthy, obese (MUHO).

Development of tyrosinase biosensor based on quantum dots/chitosan nanocomposite for detection of phenolic compounds.

A sensitive and simple amperometric biosensor for phenols was developed based on the immobilization of tyrosinase into CdS quantum dots/chitosan nanocomposite matrix. The nanocomposite film with porous nanostructure, excellent hydrophilicity and biocompatibility resulted in high enzyme loading, and the tyrosinase (Tyr) immobilized in this novel matrix retained its activity to a large extent. The CdS quantum dots/chitosan nanocomposite film was characterized by scanning electron microscopy and electrochemical impedance spectroscopy, and the parameters of the various experimental variables for the biosensor were optimized.

Carbohydrate derivative-functionalized biosensing toward highly sensitive electrochemical detection of cell surface glycan expression as cancer biomarker.

Accurate and highly sensitive detection of glycan expression on cell surface is extremely important for cancer diagnosis and therapy. Herein, a carbohydrate derivative-functionalized biosensor was developed for electrochemical detection of the expression level of cell surface glycan (mannose used as model). Thiomannosyl dimer was synthesized to design the thiomannosyl-functionalized biosensor by direct and rapid one-step protocols.

Functionalized gold nanorod-based labels for amplified electrochemical immunoassay of E. coli as indicator bacteria relevant to the quality of dairy product.

In this paper, we report an amplified electrochemical immunoassay for Escherichia coli as indicator bacteria relevant to the quality of dairy product using the functionalized gold nanorod-based labels ({dAb-AuNR-FCA}). The {dAb-AuNR-FCA} labels were designed by exploiting silica-functionalized gold nanorods (AuNR@SiO2) as the carriers for immobilization of detection antibody (dAb) and ferrocenecarboxylic acid (FCA), in which dAb was used for recognition of E. coli and FCA tags served as signal-generating molecule.

Development of highly sensitive amperometric biosensor for glucose using carbon nanosphere/sodium alginate composite matrix for enzyme immobilization.

In this study, we developed a highly sensitive amperometric biosensor for glucose detection based on glucose oxidase immobilized in a novel carbon nanosphere (CNS)/sodium alginate (SA) composite matrix. This hybrid material combined the advantages of CNS and natural biopolymer SA. This composite film was characterized by scanning electron microscope, electrochemical impedance spectroscopy and UV-vis, which indicated that the hybrid material was suitable for immobilization of glucose oxidase.

A sensitive amperometric acetylcholine biosensor based on carbon nanosphere and acetylcholinesterase modified electrode for detection of pesticide residues.

A sensitive biosensor based on acetylcholinesterase (AChE) and carbon nanosphere (CNS) immobilized on a glassy carbon electrode was developed for the detection of pesticides by the inhibition of AChE activity. The inhibition effect of the pesticides resulted in a decrease of current response of the acetylthiocholine chloride that was used as a substrate to obtain an electrochemical signal. When applied to the pesticides carbofuran and fenitrothion, the designed biosensor exhibited high sensitivity and low detection limits.

[Simplification of NIR model for citrus's sugar content based on sensory methods].

The prediction of sugar content (SC) in citrus by near-infrared spectroscopy (NIRS) and sensory test was investigated the validation whether the result of non-destructive determination methods by NIRS can meet the request of consumers' sensory or not, and the simplification of the prediction model of NIRS for citrus's SC with variables selection on the basis of meeting their demands. Result of the latter analyzed by one-way ANOVA shows that there was a significant difference influenced by individual diversity, but not by gender. After excluding the sensuous outliers, root mean standard error of deviation (RMSED) of every participator was calculated and the minimum equaled to 0.

Sensitive chemiluminescent imaging for chemoselective analysis of glycan expression on living cells using a multifunctional nanoprobe.

A novel sensitive chemiluminescent (CL) imaging method was developed for in situ monitoring of cell surface glycan expression through chemoselective labeling of carbohydrate motifs and then binding to a multifunctional nanoprobe. The nanoprobe was fabricated by assembling biotin-DNA and a large amount of horseradish peroxidase (HRP) on gold nanoparticles (AuNPs). The chemoselective labeling was performed by selective oxidization of the hydroxyl sites of sialyl and galactosyl groups on cell surfaces into aldehydes by periodate and galactose oxidase, respectively, and then aniline-catalyzed hydrazone ligation with biotin hydrazide for specific recognition to avidin.

Highly sensitive fluorescent analysis of dynamic glycan expression on living cells using glyconanoparticles and functionalized quantum dots.

A double signal amplification strategy was designed for highly sensitive and selective in situ monitoring of carbohydrate on living cells. The double signal amplification included the multiplex sandwich binding of functionalized quantum dots (QDs) to both glycan groups on the cell surface and glyconanoparticles and a cadmium cation sensitized fluorescence emission of Rhod-5N. Using the sialic acid-phenylboronic acid recognition system as a model, the 3-aminophenylboronic acid functionalized QDs (APBA-QDs) were synthesized by covalently binding APBA to mercaptopropionic acid capped CdS QDs, and the glyconanoparticles, polysialic acid stabilized gold nanoparticles (PSA-AuNPs), were prepared by a one-pot procedure.

Electrochemiluminescent biosensing of carbohydrate-functionalized CdS nanocomposites for in situ label-free analysis of cell surface carbohydrate.

A facile electrochemiluminescent (ECL) strategy for in situ label-free monitoring of carbohydrate expression on living cells was designed by integrating the specific recognition of lectin to carbohydrate with a carbohydrate-functionalized CdS nanocomposite. The mercaptopropionic acid-capped CdS quantum dots were firstly immobilized on carbon nanotubes modified electrode and then functionalized with carbohydrate using mannan as a model on the surface. The carbohydrate-functionalized CdS nanocomposite showed high ECL sensitivity and good stability, and could be used for competitive recognition to concanavalin A with the target cells in solution, which led to a change of ECL intensity due to the resistance of concanavalin A.