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Genosensor voltametri untuk pengesanan DNA organisma terubah suai genetik (GMO) telah dibangunkan berasaskan nanozarah emas (AuNPs) dan elektrod pes karbon bercetak skrin (SPE). AuNPs telah dipegunkan pada SPE melalui kaedah pertumbuhan perantara benih dan dicirikan dengan mikroskop elektron pengimbasan (SEM). 6-Mercapto-1-heksanol (MCH) telah digunakan untuk membentuk lapisan mono prob DNA rantai tunggal (ssDNA) pada SPE terubah suai AuNPs (AuNPs-SPE). Biosensor GMO telah dioptimumkan secara elektrokimia menggunakan oligonukleotida sintetik melalui teknik voltametri denyutan pembezaan (DPV). Biosensor GMO yang dioptimumkan kemudiannya digunakan untuk menganalisis sampel sebenar bagi pengesanan khusus urutan DNA dalam virus mozek kubis bunga, iaitu gen CaMV 35S. Isyarat penghibridan DNA dipantau berdasarkan arus puncak pengoksidaan penunjuk redoks asid monosulfonat antrakuinona (AQMS) semasa interkalasinya ke dalam dupleks DNA. Biosensor GMO memberi rangsangan secara linear kepada DNA terubah suai genetik (GM) antara 0.1 nM dan 300.0 nM dan had pengesanan diperoleh pada 0.06 nM. Sisihan piawai relatif (RSD) kebolehulangan biosensor GMO dianggarkan pada 6.7-7.8%. Biosensor GMO berasaskan AuNPs mempamerkan prestasi pengesanan DNA yang lebih baik daripada segi julat linear dinamik dan had pengesanan berbanding dengan biosensor GMO elektrokimia yang dilaporkan sebelum ini. Biosensor DNA elektrokimia ini menyediakan satu platform pengesanan pakai buang untuk aplikasi dalam ujian bahan GMO.

A potentiometric aspartame biosensor was fabricated by simply depositing the carboxylesterase (CES)-bonded poly(n-butyl acrylate-n-acryloxysuccimide) [CES-poly(nBA-NAS)] microspheres on a Ag/AgCl screen-printed pH selective electrode. The pH transducer was made from non-plasticized polyacrylate membrane containing a hydrogen ionophore and lipophilic salt. The immobilized CES enzyme catalyzed the enzymatic hydrolysis of aspartame to L-aspartic acid (L-Asp), L-phenylalanine and methanol. Potentiometric determination of aspartame concentration was performed by quantifying the hydrogen ion concentration produced from L-Asp. The potentiometric determination of aspartame exhibited good selectivity with near Nernstian response. The sensitivity of the biosensor was closed to the Nernstian value, i.e., 50-52 mV decade-1 with a dynamic linear response range from 10-5 to 10-2 M and detection limit approaching 10-6 M. The aspartame biosensor demonstrated good repeatability and reproducibility with relative standard deviation (RSD) of 1.9% and 1.6%, respectively (n=3). The potentiometric aspartame biosensor was demonstrated to be reliable for determining aspartame content in sweetener samples and was comparable to the conventional high-performance liquid chromatography (HPLC) method for aspartame analysis.

PurposeThis study aims to investigate the relationships among monetary cost (stimulus), perceived greenwash fear, attitude and perceived behavioural control (organism-related factors) and green hotel patronage intention (response) using the stimulus-organism-response (S-O-R) model.Design/methodology/approachA total of 262 valid questionnaires were collected. Data were collected using the purposive sampling method and tested using the partial least squares (PLS) approach.FindingsMonetary cost is positively related to only one organism-related factor which is perceived greenwash fear. All organism-related factors are positively related to response, which is green hotel patronage intention. Attitude mediates the relationship between perceived greenwash fear and green hotel patronage intention, as well as perceived behavioural control and green hotel patronage intention.Research limitations/implicationsA longitudinal study can be performed in the future to observe the actual green hotel patronage behaviour of customers.Practical implicationsGreen hoteliers should focus on the development of communication strategies to enhance their corporate reputation. Green hoteliers also need to build trust by showing their green initiatives are genuine, identify consumers who are willing to pay more for green hotels and offer promotions with price incentives such as frequency discounts, coupons and rebates to increase interest and trialability.Originality/valueFew studies have focused on the use of monetary cost as a stimulus in the S-O-R model to predict green hotel patronage intention. This study also tested the mediating effect of attitude, one of the organism-related factors, in the model.

An impedimetric aptasensor based on a polyaniline (PAni) support matrix is developed through the surface modification of a screen-printed carbon electrode (SPE) for aflatoxin B1 (AFB1) detection in foodstuffs and feedstuffs for food safety. The PAni is synthesized with the chemical oxidation method and characterized with potentiostat/galvanostat, FTIR, and UV–vis spectroscopy techniques. The stepwise fabrication procedure of the PAni-based aptasensor is characterized by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The impedimetric aptasensor is optimized using the EIS technique, and its feasibility of detecting AFB1 in real sample matrices is evaluated via a recovery study in spiked foodstuffs and feedstuffs, such as pistachio nuts, cinnamons, cloves, corn, and soybeans, with a good recovery percentage, ranging from 87.9% to 94.7%. The charge transfer resistance (RCT) at the aptasensor interface increases linearly with the AFB1 concentration in the range of 3 × 10−2 nM to 8 × 10−2 nM, with a regression coefficient (R2) value of 0.9991 and detection limit of 0.01 nM. The proposed aptasensor is highly selective towards AFB1 and partially selective to AFB2 and ochratoxin A (OTA) due to their similar structures that differ only at the carbon–carbon double bond located at C8 and C9 and the large molecule size of OTA.

Dengue virus (DENV) is a positive-sense single-stranded RNA virus and that the detection of viral RNA itself is highly desirable, which can be achieved by using RNA biosensor diagnostic method. Herein, acrylic micropolymer-based optical RNA biosensor was developed by binding anionic copper(II) phthalocyanine (CPC) planar aromatic ligand to the G-quadruplex DNA probe via end-stacking with π-system of the guanine (G) quartet, and a blue coloration was developed on the G-quadruplex microspheres. Hybridization of G-quadruplex DNA probe with target DENV serotype 2 (DENV2) RNA unfolded the G-quadruplex, and rendering release of the CPC planar optical label, causing discoloration of the G-quadruplex microbiosensor. Optical characterization of the RNA biosensor was performed by means of fiber optic reflectance spectrophotometer at maximum reflectance wavelength of 774 nm. The reflectance response enhancement of the RNA-responsive G-quadruplex-based reflectometric biosensor was linearly proportional to the target oligo DENV2 RNA concentration in the range of 2 zM-2 μM, with a 0.447 zM limit of detection and a rapid response time of 30 min. Heightening in the reflectance signal based on structural transition of G-quadruplex in response to target RNA was successfully implemented in real-time DENV2 detection in non-invasive human fluid samples (i.e. saliva and urine) under informed consent.

Green hotels help minimise the negative impact of consumption on the environment. This study examines consumers’ intention to patronise green hotels by applying the Behavioural Reasoning Theory (BRT). In the BRT, the drivers of behavioural intentions include value, reasons for, reasons against as well as global motives (attitude). This study surveyed 262 respondents in the Klang Valley, Malaysia using questionnaires. The findings indicated that reasons serve as essential linkages between consumers’ values and their attitudes. In particular, Attitude is the strongest predictor of green hotel patronage intention, followed by Reasons against Patronage, Altruism and Reasons for Patronage. Reasons against Patronage have a stronger influence on green hotel patronage intention than Reasons for Patronage. Marketers should minimise the effects of reasons against to improve green hotel patronage intention, promote consumer’s altruism value and attitude toward choosing green hotels.

A new electrochemical DNA biosensor based on mercaptopropionic acid (MPA)-capped ZnS quantum dots (MPA-ZnS QDs) immobilization matrix for covalent binding with 20-base aminated oligonucleotide has been successfully developed. Prior to the modification, screen-printed carbon paste electrode (SPE) was self-assembled with multilayer gold nanoparticles (AuNPs) and cysteamine (Cys). The inclusion of MPA-ZnS QDs semiconducting material in modified electrodes has enhanced the electron transfer between the SPE transducer and DNA leading to improved bioanalytical assay of target biomolecules. Electrochemical studies performed by cyclic voltammetry (CV) and differential pulsed voltammetry (DPV) demonstrated that the MPA-ZnS QDs modified AuNPs electrode was able to produce a lower charge transfer resistance response and hence higher electrical current response. Under optimal conditions, the immobilized synthetic DNA probe exhibited high selectivity towards synthetic target DNA. Based on the DPV response of the reduction of anthraquinone monosulphonic acid (AQMS) redox probe, the MPA-ZnS QDs-based electrochemical DNA biosensor responded to target DNA concentration from 1 × 10−9 μM to 1 × 10−3 μM with a sensitivity 1.2884 ± 0.12 µA, linear correlation coefficient (R2) of 0.9848 and limit of detection (LOD) of 1 × 10−11 μM target DNA. The DNA biosensor exhibited satisfactory reproducibility with an average relative standard deviation (RSD) of 7.4%. The proposed electrochemical transducer substrate has been employed to immobilize the aminated Arowana fish (Scleropages formosus) DNA probe. The DNA biosensor showed linearity to target DNA from 1 × 10−11 to 1 × 10−6 µM (R2 = 0.9785) with sensitivity 1.1251 ± 0.243 µA and LOD of 1 × 10−11 µM. The biosensor has been successfully used to determine the gender of Arowana fish without incorporating toxic raw materials previously employed in the hazardous processing conditions of polypyrrole chemical conducting polymer, whereby the cleaning step becomes difficult with thicker films due to high levels of toxic residues from the decrease in polymerization efficacy as films grew.

PurposeThis study aims to examine the influence of environmental knowledge on perceived green benefits and green hotel patronage intention. It also aims to investigate the influence of perceived green benefits on attitude towards green hotel stay and patronage intention.Design/methodology/approachThe purposive sampling method was used in this study. A total of 262 respondents completed the survey questionnaire. For data testing, the partial least squares approach was used.FindingsEnvironmental knowledge positively influenced the intention to patronise a green hotel and all the perceived green benefits – functional, emotional, social and epistemic benefits. Perceived green benefits did not influence green hotel patronage intention directly, but all the benefits promoted a favourable attitude towards green hotel stay.Research limitations/implicationsFuture studies can replicate this study to examine whether consumers in other cities or countries perceive green benefits similarly or differently. The current model can also be used to explore other hospitality and tourism settings.Practical implicationsGreen hoteliers should highlight all the four perceived green benefits in their marketing communication materials, especially functional and epistemic benefits that have greater effect on attitude. Green hoteliers can also collaborate with local government, educational institutions and travel agencies to develop pro-environmental materials to increase environmental knowledge of consumers.Originality/valueFew studies have examined the relationships among environmental knowledge, perceived green benefits with the inclusion of epistemic benefit, attitude and green hotel patronage intention in a single framework.

The coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a major public health outbreak in late 2019 and was proclaimed a global pandemic in March 2020. A reflectometric-based RNA biosensor was developed by using cysteamine-stabilized gold nanoparticles (cysAuNPs) as the colorimetric probe for bioassay of COVID-19 RNA (SARS-CoV-2 RNA) sequence. The cysAuNPs aggregated in the presence of DNA probes via cationic and anionic electrostatic attraction between the positively charged cysteamine ligands and the negatively charged sugar-phosphate backbone of DNA, whilst in the presence of target RNAs, the specific recognition between DNA probes and targets depleted the electrostatic interaction between the DNA probes and cysAuNPs signal probe, leading to dispersed particles. This has rendered a remarkable shifting in the surface plasmon resonance (SPR) on the basis of visual color change of the RNA biosensor from red to purplish hue at the wavelength of 765 nm. Optical evaluation of SARS-CoV-2 RNA by means on reflectance transduction of the RNA biosensor based on cysAuNPs optical sensing probes demonstrated rapid response time of 30 min with high sensitivity, good linearity and high reproducibility across a COVID-19 RNA concentration range of 25 nM to 200 nM, and limit of detection (LOD) at 0.12 nM. qPCR amplification of SARS-CoV-2 viral RNA showed good agreement with the proposed RNA biosensor by using spiked RNA samples of the oropharyngeal swab from COVID-19 patients. Therefore, this assay is useful for rapid and early diagnosis of COVID-19 disease including asymptomatic carriers with low viral load even in the presence of co-infection with other viruses that manifest similar respiratory symptoms.

The aim of this study was to depict a comprehensive description of near miss research and clarify research gaps.Learning from near miss can provide early warnings and is critical for proactive and prospective risk management. Because of the lack of structured reviews, there is little knowledge about how near miss management has been managed in the past.This review was conducted following the Arksey and O'Malley's methodology and reported by the PRISMA Extension for Scoping Reviews.Sixty-seven research articles were included. The results revealed that the most investigated fields include near miss reporting, near miss characteristics, and good catch project. Poor theoretical investigation, underreporting, and inconsistent outcome indicators are major problems.Solely understanding causes of near misses cannot guarantee effective learning; we also need to apply appropriate learning theories. Advanced technologies should be applied to solve long-standing underreporting issues. Accurate and consistent indicators should be applied in near miss research and management.

In this study, communities’ psychosocial judgements (relationship, awareness, responsibility, and attitude) were evaluated in relation to DNA-based dengue kit accessibility. It was carried out by handing out 100 structured questionnaires (Kajang Housing (KjH): 40, Kajang Industrial (KjI): 40, Kuala Selangor (KuS): 20). From our descriptive analyses, KuS respondents exhibited a closer relationship with their neighbours (100%) compared to other respondents. KjH, KjI and KuS respondents know very little about dengue vector species. While KjH is leading the other two study areas, KjI and KuS in terms of knowing all symptoms associated with dengue fever (DF), KuS shows more interest to participate in dengue campaigns and/or prevention and control programs compared to KjH and KjI. Not more than 25% of total respondents are willing to offer transportation or nurturing their neighbours back to health. While KjI is more confident to use DNA biosensor when outside of their community, not more than 35% of total respondents are confident enough to use it within their neighbourhood. All communities, especially the affected ones, should take a proactive step by making use of DNA biosensor as an early warning tool, in conjunction with good psychosocial behaviours towards dengue, to achieve sustainable health promotion in managing dengue disaster.

Green hotels help protect the environment by performing various environmentally friendly practices. This study examines the reason constructs to provide unique insights on consumers’ motivational mechanisms in green hotel patronage intention. This study aims to investigate altruism value, reasons for patronage and reasons against patronage as predictors of green hotel patronage intention. This study also examines the mediating effect of both reasons in the relationship between altruism and green hotel patronage intention. The usable data of 262 respondents were collected through the distribution of questionnaire in the Klang Valley, Malaysia. The results demonstrated that both reasons for and reasons against patronage have a significant influence on green hotel patronage intention. Reasons for patronage were also found to be a mediator between altruism and green hotel patronage intention. This study also shows that altruism value significantly predicts green hotel patronage intention and reasons for patronage. Thus, green hoteliers should target potential altruistic consumers and stimulate altruistic values of people. In addition, they should strengthen the reasons for patronage and address the reasons against patronage so that consumers see more value in patronising green hotels.

Awareness of both chemical safety and chemical security is important in order to avoid or reduce any adverse effects of chemical use; hence, both these topics should be incorporated into the educat...

Optical biosensor for the detection of formaldehyde has been developed based on the transparent enzymatic stacked membranes system on the glass substrate, and employing optical absorption transducer with H+ ion-selective Nile Blue chromoionophore (NBCM) dye-doped methacrylic acrylic (MB28) copolymer membrane as the optode membrane. Alcohol oxidase (AOx) enzymes were entrapped within the biocompatible sol–gel matrix and deposited on top of the pH optode membrane. As the uppermost catalytic membrane catalyzes the oxidative conversion of formaldehyde to formic acid and hydrogen peroxide, the immobilized NBCM undergoes protonation reaction and forms HNBCM+, the dark blue ion-chromoionophore complex via H+ ion transfer reaction within the soft and flexible MB28 polymeric membrane. This rendered the enzymatic optode membrane absorbed a high yellow light intensity from the light source and exhibited maximum absorption peaks at 610 and 660 nm. Optical evaluation of formaldehyde by means on UV–vis absorption transduction of the enzymatic stacked membranes demonstrated rapid response time of 10 min with high sensitivity, good linearity and high reproducibility across a wide formaldehyde concentration range of 1 × 10−3–1 × 103 mM (R2 = 0.9913), and limit of detection (LOD) at 1 × 10−3 mM, which could be useful for formaldehyde assay in industrial, agricultural, environmental, food and beverages as well as medical samples. The formaldehyde concentration in snapper fish, pomfret fish and threadfin fish samples determined by the proposed optical enzymatic biosensor were very much close to the formaldehyde concentration values determined by the UV–vis spectrophotometric NASH standard method based on the statistical t-test. This suggests that the optical biosensor can be used as a reliable method for quantitative determination of formaldehyde levels in food samples.

The emergence of highly pathogenic and deadly human coronaviruses, namely SARS-CoV and MERS-CoV within the past two decades and currently SARS-CoV-2, have resulted in millions of human death across the world. In addition, other human viral diseases, such as mosquito borne-viral diseases and blood-borne viruses, also contribute to a higher risk of death in severe cases. To date, there is no specific drug or medicine available to cure these human viral diseases. Therefore, the early and rapid detection without compromising the test accuracy is required in order to provide a suitable treatment for the containment of the diseases. Recently, nanomaterials-based biosensors have attracted enormous interest due to their biological activities and unique sensing properties, which enable the detection of analytes such as nucleic acid (DNA or RNA), aptamers, and proteins in clinical samples. In addition, the advances of nanotechnologies also enable the development of miniaturized detection systems for point-of-care (POC) biosensors, which could be a new strategy for detecting human viral diseases. The detection of virus-specific genes by using single-stranded DNA (ssDNA) probes has become a particular interest due to their higher sensitivity and specificity compared to immunological methods based on antibody or antigen for early diagnosis of viral infection. Hence, this review has been developed to provide an overview of the current development of nanoparticles-based biosensors that target pathogenic RNA viruses, toward a robust and effective detection strategy of the existing or newly emerging human viral diseases such as SARS-CoV-2. This review emphasizes the nanoparticles-based biosensors developed using noble metals such as gold (Au) and silver (Ag) by virtue of their powerful characteristics as a signal amplifier or enhancer in the detection of nucleic acid. In addition, this review provides a broad knowledge with respect to several analytical methods involved in the development of nanoparticles-based biosensors for the detection of viral nucleic acid using both optical and electrochemical techniques.

A microbial optosensor for nitrite was constructed based on biomimetic silica nanoparticles, which were doped with R5, a polypeptide component of silaffin, as a robust biosilica immobilization matrix entrapped with Raoultella planticola and NAD(P)H cofactor during the in vitro biosilicification process of silica nanoparticles. Ruthenium(II)(bipy)2(phenanthroline-benzoylthiourea), the chromophoric pH probe, was physically adsorbed on the resulting biogenic nanosilica. Optical quantitation of the nitrite concentration was performed via reflectance transduction of the bio-doped microbial nanosilica at a maximum reflectance of 608 nm, due to the deprotonation of phen-BT ligands in the ruthenium complex, while the intracellular enzyme expression system catalyzed the enzymatic reduction of nitrite. Reflectance enhancement of the microbial optosensor was linearly proportional to the nitrite concentration from 1–100 mg L−1, with a 0.25 mg L−1 limit of detection and a rapid response time of 4 min. The proposed microbial optosensor showed good stability of >2 weeks, great repeatability for 5 repetitive assays (relative standard deviation, (RSD) = 0.2–1.4%), high reproducibility (RSD = 2.5%), and a negligible response to common interferents found in processed meats, such as NO3−, NH4+, K+, Ca2+, and Mg2+ ions, was observed. The microbial biosensor demonstrated an excellent capacity to provide an accurate estimation of nitrite in several cured meat samples via validation using a standard UV-vis spectrophotometric Griess assay.

Plant growth-promoting bacteria (PGPB) have great potential to provide economical and sustainable solutions to current agricultural challenges. The Methylobacteria which are frequently present in the phyllosphere can promote plant growth and development. The Methylobacterium genus is composed mostly of pink-pigmented facultative methylotrophic bacteria, utilizing organic one-carbon compounds as the sole carbon and energy source for growth. Methylobacterium spp. have been isolated from diverse environments, especially from the surface of plants, because they can oxidize and assimilate methanol released by plant leaves as a byproduct of pectin formation during cell wall synthesis. Members of the Methylobacterium genus are good candidates as PGPB due to their positive impact on plant health and growth; they provide nutrients to plants, modulate phytohormone levels, and protect plants against pathogens. In this paper, interactions between Methylobacterium spp. and plants and how the bacteria promote crop growth is reviewed. Moreover, the following examples of how to engineer microbiomes of plants using plant-growth-promoting Methylobacterium are discussed in the present review: introducing external Methylobacterium spp. to plants, introducing functional genes or clusters to resident Methylobacterium spp. of crops, and enhancing the abilities of Methylobacterium spp. to promote plant growth by random mutation, acclimation, and engineering.

An optical genosensor based on Schiff base complex (Zn2+ salphen) DNA label and acrylic microspheres (AMs) as polymer support of the capturing DNA probe (cpDNA) was developed for dengue virus serotype 2 (DEN-2) detection via reflectance spectrophotometric method. The solid-state optical DNA biosensor showed high selectivity and specificity up to one-base mismatch in the target DNA sequence owing to the salphen chemical structure that is rich in localized electrons, and allowed π-π stacking interaction between stacked base pairs of double-stranded DNA (dsDNA). The reflectometric DNA microsensor demonstrated a broad linear detection range towards DEN-2 DNA from 1 × 10–15 M to 1 × 10−3 M with a low limit of detection (LOD) obtained at 1.21 × 10–16 M. The DNA biosensor gave reproducible optical response with a satisfactory relative standard deviation (RSD) at 3.1%, (n = 3), and the reflectance response was stable even after four regeneration cycles of the DNA biosensor. The optical genosensor was proven comparable with standard reverse transcription polymerase chain reaction (RT-PCR) in detecting DEN-2 genome acquired from clinical samples of serum, urine and saliva of dengue virus infected patients under informed consent. The developed reflectometric DNA biosensor is advantageous in offering an early DEN-2 diagnosis, when fever symptom started to manifest in patient.

An optical biosensor employing immobilized haloalkane dehalogenase (HLD), the halide degrading enzyme for the detection of halogenated organic in environmental water and drinking water samples was developed. The enzymatic biosensor was fabricated by incorporating H+ ion selective chromoionophore ETH5294 and HLD enzyme in a stacked chitosan films system on a glass slide. Hydrolytic dehalogenation of dichloroethane (DCA) by the carbon-halide degrading HLD enzyme resulting in the release of a halogen, a proton and a primary alcohol. The halocarbon concentration was optically transduced by the pH transducer layer as a result of protonation reaction of the chromoionophore pH indicator dye embedded in the underneath layer. The resulting colour change of the protonated chromoionophore was measured by fiber optic reflectance spectrophotometry method. Under optimized conditions the detection limit of the proposed reflectance-based enzymatic biosensor membrane was estimated to be 1 mg L−1 with a wide dynamic linear concentration range of 5–60 mg L−1 DCA (R2 = 0.9792) and satisfactory reproducibility within the relative standard deviation (RSD) range of 3.4–4.3%. Validation test demonstrated that the optical halocarbon biosensor could be a promising tool for rapid (6 min) in situ and direct evaluation of organohalide in river water, tap water and bottled water samples without any sample pre-treatment or extraction steps.

The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) subtype ionotropic glutamate receptors are attractive antiepileptic targets responsible for mediating the majority of excitatory neurotransmission and plasticity. The noncompetitive antagonists obtain more and more attention as drug candidates for treatment of the neurological diseases involving excessive activity of AMPARs, due to they regulate AMPA receptors (AMPARs) activity independently of endogenous glutamate levels unlike the competitive antagonists. Development of novel AMPAR noncompetitive antagonists, which are safer and more efficacious than competitive antagonists, is highly under demand. Here, we present the discovery of novel antagonists against AMPAR through Structure-Based Virtual Screening (SBVS). Three compounds were successfully distinguished by several different filtering strategies, namely STOCK6S-10902, STOCK1N-49134 and STOCK5S-68665. The interaction mode of these compounds was further explored through molecular dynamics simulation, binding free energy calculation and the binding free energy decomposition. It is demonstrated that some residues within the binding pocket, which have been proved their importance in antagonist binding and gating, form strong hydrogen bond interactions with these three molecules. In particular, H-bond interactions with high occupancies between Ser516, Ser788 and STOCK6S-10902 and Ser516, Asn791 and STOCK1N-49134 were observed. The three hit compounds with new scaffolds and the detailed binding modes could potentially serve as a starting point for further optimization and development.

A reflectometric biosensor for enzymatic determination of halogenated organic pollutant in environmental water sample was developed. Polyacrylate microspheres modified with succinimide functional groups were employed as the substrate matrix for covalent immobilization of haloalkane dehalogenase (DhlA) enzyme, and ETH5294 Nile Blue chromoionophore (NBC) pH dye was physically immobilized on the acrylic micromatrix to function as an optical proton sensor. The hydrolytic dehalogenation of halocarbon catalyzed by the immobilized DhlA resulting in the release of a halogen and a proton, which protonated the immobilized NBC proton indicator, and a colour change of the biosensor from violet to blue was measured with a reflectance spectrophotometer for indirect quantification of the halogenated hydrocarbon concentration. The enzymatic halocarbon reflectance biosensor exhibited a dynamic linear response range of 1–30 mg L−1 1,2-dichloroethane (DCA) (R2 = 0.9762) with a detection limit of 0.3 mg L−1. The proposed enzymatic biosensor gave rapid response, within 2 min, towards the detection of 50 mg L−1 DCA at 662 nm, and demonstrated stable response up to 6 days of storage period at 4 °C and pH 8.0. Validation between the developed biosensor with standard gas chromatography–electron capture detector (GC-ECD) showed that both methods have a comparable accuracy in detecting halocarbon species.

Biosensor optik berasaskan hemoglobin (Hb) terpegun pada mikrosfera poli(n-butil akrilat-co-N-akriloksisuksinimida) [poli(nBA-NAS)] telah dibangunkan bagi mengesan kepekatan ion nitrit (NO2-). Kompleks HEM ferum dalam Hb memangkinkan tindak balas penurunan ion NO2- kepada nitrik oksida (NO) lalu bergabung dengan deoksihemoglobin (HbFe2+) membentuk kompleks ferum-nitrosil-hemoglobin (HbFe2+-NO) yang berwarna hijau kekuningan. Spektrofotometer pantulan gentian optik digunakan untuk memantau kepekatan ion NO2- secara kuantitatif berdasarkan perubahan warna Hb terpegun pada mikrosfera poliakrilat daripada perang kemerahan ke hijau kekuningan pada panjang gelombang pantulan maksimum 668 nm. Pencirian terhadap biosensor nitrit reflektometrik melibatkan ujian kesan pH, kesan kepekatan Hb, julat rangsangan linear, kebolehasilan, jangka hayat dan kesan gangguan ion telah dijalankan. Biosensor ion NO2- optik terbangun memaparkan julat linear dinamik daripada 5 hingga 50 mg mL-1 (R2=0.9894) pada pH7.0 dengan had pengesanan (LOD) sebanyak 3.3 mg mL-1 dan nilai sisihan piawai relatif (RSD) kebolehasilan biosensor sebanyak 5.8%. Jangka hayat biosensor optik nitrit tersebut adalah selama 36 hari dan majoriti ion asing yang sering wujud bersama ion NO2- dalam sampel air semula jadi tidak menunjukkan kesan gangguan yang bererti terhadap penentuan ion NO2- menggunakan biosensor optik terbangun kecuali ion Hg2+, Ag+, Br- dan S2-.

In view of the growing need for rapid and non-destructive method for monitoring of fish freshness to secure the safety standard of food, a reflectometric biosensor kit has been developed for in situ and real-time analysis of creatine as freshness marker. The optical bienzymatic creatine biosensor was fabricated by covalent grafting of both creatinase (CI) and urease (Ur) on the pH chromoionophore ETH 5295-doped poly(styrene-co-acrylic acid) (PSA) latex microspheres via EDC/NHS coupling chemistry. An optical fiber reflectance spectrophotometer was employed for reflectance measurement of the biorecognition phase for quantification of creatine levels, which can be used as the indicator of the extent of fish spoilage for direct evaluation of fish freshness. The dynamic linear response range of the reflectance creatine biosensor was obtained from 16 to 48 mM, which corresponds to the physiological range of creatine in fish body surface metabolite with a reproducibility of less than 2% relative standard deviation (RSD). The biosensor response time was about 7 min and did not show interference by some important biogenic amines (BAs), amino acids and nitrogen compounds normally co-exist with creatine in the biofluid of fish surface such as histamine, phenylalanine, tyrosine and taurine except sarcosine and uric acid.

Programmed cell death (PCD) plays a critical role throughout the lives of plants, it is regarded as a highly regulated and active process of plant cell death during the times of biotic or abiotic stress. This study aims to provide developmental anatomical characteristics of the interxylary cork formation in the roots of Astragalus. membranaceus var. mongholicus, and to subsequently show cytomorphological evidence that PCD is involved in the development of rhytidome and interxylary cork. The developmental anatomy of rhytidome and interxylary cork of the perennial fresh main root of A. membranaceus var. mongholicus was studied using light microscopy, whereas the PCD in the development of rhytidome and interxylary cork was studied using fluorescence microscopy and transmission electron microscopy. Histologically, it was observed that the parenchyma cells of secondary phloem and xylem in roots recovered their meristematic ability, and later developed into rhytidome and interxylary cork. Cytologically, ultrastructural characteristics such as nucleus malformation, vacuole disappearance, mitochondrial degeneration, and vesicle filling were observed. In roots, the nucleus of the phloem parenchyma cells were terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive from the pre-rhytidome stage to the formation of rhytidome stage and 4',6-diamidino-2-phenylindole dihydrochloride (DAPI)-negative during the mature rhytidome stage. The TUNEL assay of the xylem parenchyma cells showed positive characteristics from the early stage of interxylary cork formation to the interxylary cork formation stage, whereas DAPI-negative characteristics were observed in the mature interxylary cork. Gel electrophoresis showed that DNA cleavage was random. Our results indicated that the formation of the rhytidome and interxylary cork involved the PCD process.

Abundant of preparatory works have recognized that fluorescent sensors based on 8-aminoquinoline are popular tools to detect Zn2+ ions in environmental and biological applications. Along with these studies, researchers started to introduce a variety of carboxamido group into an 8-aminoquinoline molecule in forming 8-amidoquinoline derivatives. Therefore, this systematic review aims to introduce a general overview of the fluorophore 8-aminoquinoline as Zn2+ receptors and to provide comparisons of collected studies that related to 8-amidoquinoline derivatives as fluorophore probe of the sensor. According to PRISMA systematic searches strategy, 13 articles were analyzed for trends, research designs, results and discussion, subject samples, and remarks or conclusions. We found cross-sectional studies with four aspects in zinc sensing that have been targeted; binding studies via titration, detection's limit, interferences studies, and validation of the study. Hence, this paper also included assessments of those criteria and the trends of development of 8-amidoquinoline derivatives based-zinc fluorescent chemosensor. It also showed that most of the researches conducted in China. In conclusion, this study identified various research designs of fluorescent chemosensors based on 8-amidoquinoline prolong with the effectiveness and potential as a recognition probe to assist the detection of zinc. Hence, elucidation of those derivatives essential to be explored because more studies are needed to improve the sensing criteria of the zinc sensor

Carrageenans are linear sulphated polysaccharides that are commonly added into confectionery products but may exert a detrimental effect to human health. A new and simpler way of carrageenan determination based on an optical sensor utilizing a methylcellulose/poly(n-butyl acrylate) (Mc/PnBA) composite membrane with immobilized methylene blue (MB) was developed. The hydrophilic Mc polymer membrane was successfully modified with a more hydrophobic acrylic polymer. This was to produce an insoluble membrane at room temperature where MB reagent could be immobilized to build an optical sensor for carrageenan analysis. The fluorescence intensity of MB in the composite membrane was found to be proportional to the carrageenan concentrations in a linear manner (1.0–20.0 mg L−1, R2 = 0.992) and with a detection limit at 0.4 mg L−1. Recovery of spiked carrageenan into commercial fruit juice products showed percentage recoveries between 90% and 102%. The optical sensor has the advantages of improved sensitivity and better selectivity to carrageenan when compared to other types of hydrocolloids. Its sensitivity was comparable to most sophisticated techniques for carageenan analysis but better than other types of optical sensors. Thus, this sensor provides a simple, rapid, and sensitive means for carageenan analysis.

Histamine is one of the important biomarkers for food spoilage in the food sectors. In the present study, a rapid and simple analytical tool has been developed to detect histamine as an indirect strategy to monitor food freshness level. Optical histamine sensor with carboxyl-substituted Schiff base zinc(II) complex with hydroxypropoxy side chain deposited onto titanium dioxide nanoparticles was fabricated and was found to respond successfully to histamine. The Schiff base zinc(II) complex-histamine binding generated an enhancement of the fluorescent signal. Under the optimal reaction condition, the developed sensor can detect down to 2.53 × 10

Graphene decorated with graphitic nanospheres functionalized with pyrene butyric acid (PBA) is used for the first time to fabricate a DNA biosensor. The electrode was formed by attaching a DNA probe onto PBA, which had been stacked onto a graphene material decorated with graphene nanospheres (GNSs). The nanomaterial was drop-coated onto a carbon screen-printed electrode (SPE) to create the GNS-PBA modified electrode (GNS-PBA/SPE). A simple method was used to produce GNS by annealing graphene oxide (GO) solution at high temperature. Field emission scanning electron micrographs confirmed the presence of a spherical shape of GNS with a diameter range of 40–80 nm. A stable and uniform PBA-modified GNS (GNS-PBA) was obtained with a facile ultrasonication step. Thus allowing aminated DNA probes of genetically modified (GM) soybean to be attached to the nanomaterials to form the DNA biosensor. The GNS-PBA/SPE exhibited excellent electrical conductivity via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) tests using potassium ferricyanide (K3[Fe(CN)6]) as the electroactive probe. By employing an anthraquinone monosulfonic acid (AQMS) redox intercalator as the DNA hybridization indicator, the biosensor response was evaluated using the DPV electrochemical method. A good linear relationship between AQMS oxidation peak current and target DNA concentrations from 1.0 × 10−16 to 1.0 × 10−8 M with a limit of detection (LOD) of less than 1.0 × 10−16 M was obtained. Selectivity experiments revealed that the voltammetric GM DNA biosensor could discriminate complementary sequences of GM soybean from non-complementary sequences and hence good recoveries were obtained for real GM soybean sample analysis. The main advantage of using GNS is an improvement of the DNA biosensor analytical performance.

A DNA micro-optode for dengue virus detection was developed based on the sandwich hybridization strategy of DNAs on succinimide-functionalized poly(n-butyl acrylate) (poly(nBA-NAS)) microspheres. Gold nanoparticles (AuNPs) with an average diameter of ~20 nm were synthesized using a centrifugation-based method and adsorbed on the submicrometer-sized polyelectrolyte-coated poly(styrene-co-acrylic acid) (PSA) latex particles via an electrostatic method. The AuNP&ndash, latex spheres were attached to the thiolated reporter probe (rDNA) by Au&ndash, thiol binding to functionalize as an optical gold&ndash, latex&ndash, rDNA label. The one-step sandwich hybridization recognition involved a pair of a DNA probe, i.e., capture probe (pDNA), and AuNP&ndash, PSA reporter label that flanked the target DNA (complementary DNA (cDNA)). The concentration of dengue virus cDNA was optically transduced by immobilized AuNP&ndash, PSA&ndash, rDNA conjugates as the DNA micro-optode exhibited a violet hue upon the DNA sandwich hybridization reaction, which could be monitored by a fiber-optic reflectance spectrophotometer at 637 nm. The optical genosensor showed a linear reflectance response over a wide cDNA concentration range from 1.0 &times, 10&minus, 21 M to 1.0 &times, 12 M cDNA (R2 = 0.9807) with a limit of detection (LOD) of 1 &times, 29 M. The DNA biosensor was reusable for three consecutive applications after regeneration with mild sodium hydroxide. The sandwich-type optical biosensor was well validated with a molecular reverse transcription polymerase chain reaction (RT-PCR) technique for screening of dengue virus in clinical samples, e.g., serum, urine, and saliva from dengue virus-infected patients under informed consent.

A novel label-free electrochemical DNA biosensor was constructed for the determination of Escherichia coli bacteria in environmental water samples. The aminated DNA probe was immobilized onto hollow silica microspheres (HSMs) functionalized with 3-aminopropyltriethoxysilane and deposited onto a screen-printed electrode (SPE) carbon paste with supported gold nanoparticles (AuNPs). The biosensor was optimized for higher specificity and sensitivity. The label-free E. coli DNA biosensor exhibited a dynamic linear response range of 1 &times, 10&minus, 10 &micro, M to 1 &times, 5 &micro, M (R2 = 0.982), with a limit of detection at 1.95 &times, 15 &micro, M, without a redox mediator. The sensitivity of the developed DNA biosensor was comparable to the non-complementary and single-base mismatched DNA. The DNA biosensor demonstrated a stable response up to 21 days of storage at 4 ℃ and pH 7. The DNA biosensor response was regenerable over three successive regeneration and rehybridization cycles.

Pembangunan model biosensor DNA berasaskan pengikatan dan interaksi kompleks logam sebagai penanda penghibridan DNA boleh digunakan untuk diagnosis awal virus denggi melalui penghibridan DNA denggi sebagai DNA sasaran. Kompleks nikel(II) salfen dengan rantai sisi piperidina berjaya disintesis dan pencirian dijalankan dengan menggunakan Spektroskopi Magnetik Nukleus (NMR), Spektroskopi inframerah (FTIR), spektrometri jisim dan kolorimetri pengimbasan pembezaan. Jenis perikatan dan interaksi antara kompleks nikel(II) salfen dengan rantai sisi piperidina dan DNA denggi dikaji dengan pentitratan DNA ultralembayung nampak. Berdasarkan spektrum ultralembayung nampak, hipokromisme dan anjakan merah (batokromisme) diperhatikan apabila kompleks nikel(II) salfen dengan rantai sisi piperidina dititratkan dengan DNA denggi menunjukkan pembentukan kompleks baru. Kompleks nikel(II) salfen dengan rantai sisi piperidina berinteraksi dengan DNA denggi secara perikatan interkalasi dengan pemalar perikatan, Kb= 4.576×105 M-1. Penemuan ini sangat berharga dalam menjadikan kompleks nikel(II) salfen sebagai penanda penghibridan bagi biosensor DNA optik untuk mengesan kehadiran virus denggi.

A microspheres-based microbial optosensor for NO 2 − ion quantitation was constructed by using immobilized Raoutella planticola ( R. planticola ), the bacterium expressing NAD(P)H nitrite reductase (NiR) enzyme, which was isolated from local edible bird’s nest (EBN) via microbial technique. The whole cells and the lipophilic Nile Blue chromoionophore (NBC) were physically adsorbed on the self-adhesive photocurable poly( n -butyl acrylate-co- N -acryloxysuccinimide) [poly(nBA-NAS)] microspheres, whilst the reduced co-enzyme NAD(P)H was covalently immobilized on the succinimide-functionalized acrylic microspheres via peptide link to produce a reagentless nitrite biosensing system. As the microbial bio-optode responded to nitrite through colour change from blue to pink, a facile reflectometric approach was adopted to measure reflectance intensity at 639 nm, before and after reaction with nitrite at optimum pH 8. The optosensor could quantify NO 2 − ion concentration within a dynamic linear response range of 0.5–400 mg L −1 with a limit of detection (LOD) of 0.2 mg L −1 . The large surface area to volume ratio of the acrylic microspheres allowed solid-state diffusional mass transfer of the substrate to occur at micro-bio-optode surface, and an equilibrium response was achieved within 5 min. The practical feasibility of using the bio-optode for nitrite assay in food matrix sample showed good agreement with standard ion chromatography method.

Aim To translate the Strategic Learning Assessment Map into Chinese and validate it in Chinese nursing organisations. Background Nursing is the largest occupational organisation in the health sector and its adaptation and innovation are important for the realisation of sustainable development goals. Organisational learning is critical in cultivating the adaptive and innovative abilities of organisations, but there is limited research on its measurement. Although the Strategic Learning Assessment Map is a widely acknowledged organisational measurement instrument, it has not yet been adapted and validated in China. Design A cross-sectional study design was used. Methods The Chinese version of the Strategic Learning Assessment Map was generated through forward-backward translation and was tested with a convenience sample of 2745 nurses from 7 administrative regions of mainland China. The internal consistency, content validity, structural validity and theoretical framework were examined. Results Results validated the theoretical framework and showed excellent content validity, convergent validity and fitness of the measurement model; only discriminant validity was not satisfactory. Cronbach’s α values for the overall scale and its subscales ranged from 0.97 to 0.99. Conclusions The Chinese version of the Strategic Learning Assessment Map is a reliable organisational learning instrument for Chinese nursing organisations.

An electrochemical DNA biosensor for DNA determination of genetically modified (GM) soybean (CaMV 35S target genes) was developed utilizing a new detection concept based on the adsoption of anthraquinone‐2‐sulphonic acid (AQMS) on the reduced graphene oxide nano‐particles (rGO) during DNA hybridization events. The aminated DNA probe for CaMV 35S was immobilized onto poly(n‐butyl acrylate) film modified with succinimide functional groups [poly(nBA‐NAS)] via peptide covalent bond. Nanosheets of rGO were entrapped in the poly(nBA‐NAS) film to form a conducting [poly(nBA‐NAS)‐rGO] film of the DNA biosensor. Besides facilitating the electron transfer reactions, the rGO also functioned as an adsorbent for AQMS. The sensing mechanism of the proposed DNA biosensor involved measuring the oxidation current of the AQMS adsorbed on the electrode surface at −0.50 V using differential pulse voltammetry (DPV) before and after a DNA hybridization event. Under optimum conditions, the DNA biosensor demonstrated a linear proportionality between AQMS oxidation signal and logarithm cDNA concentration from 1.0×10−15 M to 1.0×10−8 M target DNA with a detection limit of 6.3×10−16 M. The electrochemical DNA biosensor possessed good selectivity and a shelf life of about 40 days with relative standard deviation of reproducibility obtained in the range of 3.7–4.6% (n=5). Evaluation of the DNA biosensor using GM soybean DNA extracts showed excellent recovery percentages of 97.2–104.0.

An optical enzymatic phenylalanine biosensor for non-invasive evaluation of fish freshness using biofluid from the fish body surface has been developed based on phenylalanine dehydrogenase (PDH) and nicotinamide adenine dinucleotide (NAD+) chemisorbed on the graphene oxide-chitosan (GO/CT) nanocomposites film. The immobilized PDH on the biosensor surface via EDC/NHS coupling strategy catalyzed the oxidative deamination of phenylalanine to phenylpyruvate, and concomitantly converted the cofactor NAD+ (oxidized form) to fluorophore NADH (reduced form), which can be quantified by using fluorescence spectrophotometer. The phenylalanine-responsive fluorescent biosensor showed a dynamic linear concentration range between 0.03 mM and 0.24 mM phenylalanine at 644 nm emission wavelength with an excitation wavelength of 320 nm. The limit of detection (LOD) of the fluorometric phenylalanine biosensor was estimated at 0.02 mM with a fast response time of 1 min. No significant interference by amines-synthesized amino acids, such as histamine, creatine, sarcosine, creatinine, tyrosine and uric acid at typical physiological levels commonly co-exist with phenylalanine in the biofluid metabolite of fish towards fresh fish quality grading. Validation study of the GO/CT catalytic film revealed excellent practicality of the biosensor in biological fluid sample of tuna fish (Euthynnus affinis) for detection of phenylalanine. The proposed GO/CT nanocomposites biofilm offers rapid test that can be assessed with an easy manner to rapidly analyze large number of samples in a short period of time.

The presence of mycotoxins in foodstuffs and feedstuffs is a serious concern for human health. The detection of mycotoxins is therefore necessary as a preventive action to avoid the harmful contamination of foodstuffs and animal feed. In comparison with the considerable expense of treating contaminated foodstuffs, early detection is a cost-effective way to ensure food safety. The high affinity of bio-recognition molecules to mycotoxins has led to the development of affinity columns for sample pre-treatment and the development of biosensors for the quantitative analysis of mycotoxins. Aptamers are a very attractive class of biological receptors that are currently in great demand for the development of new biosensors. In this review, the improvement in the materials and methodology, and the working principles and performance of both conventional and recently developed methods are discussed. The key features and applications of the fundamental recognition elements, such as antibodies and aptamers are addressed. Recent advances in aptasensors that are based on different electrochemical (EC) transducers are reviewed in detail, especially from the perspective of the diagnostic mechanism; in addition, a brief introduction of some commercially available mycotoxin detection kits is provided.

The presence of histamine in foods due to improper storage of foods is associated with toxicological risk and quality indicators. An impedimetric sensor was developed by immobilising fluoro-substituted hydroxyl functionalised Schiff base zinc(II) complex on the titanium dioxide nanoparticles-coated fluorine-doped tin oxide (nano-TiO2/FTO) electrode for sensitive and selective determination of histamine with high recovery ability. Elucidation of chemical structure for the Zn(II)-Schiff base complex has been conducted by employing NMR, FTIR and ESI-MS spectroscopic techniques, whilst Schiff base complex-histamine binding affinity was evaluated by means of Raman spectroscopy, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical impedimetric sensor showed charge-transfer resistance (Rct) response that is proportional to the logarithm of histamine concentration between 1.0 × 10−7 M and 1.0 × 10−2 M (R² = 0.9894), which is useful for the determination of typical histamine levels in food samples. The impedimetric sensor exhibited high selectivity towards histamine over other biogenic amines occurring in foods e.g. putrescine and cadaverine, and some other amine compounds e.g. ethanolamine (1˚ amine), 1,2-phenylenediamine (1,2-PDA, 2˚ amine) and triethylamine (TED, 3˚ amine). The Schiff base complex electrode is reusable, and rapid regeneration of the electrode within 30 s simply by using water allows high-throughput histamine assay. Impedimetric detection of histamine in salmon fillet at the Schiff base complex electrode has been validated with HPLC and showed high promise to be applied as an inexpensive and effective tool for food safety surveillance.

A membrane-based potentiometric biosensor has been fabricated from poly(n-butyl acrylate-co-N-acryloxysuccinimide as both enzyme supporting matrix and pH-sensitive transducer on the Ag/AgCl screen-printed electrode for rapid and facile determination of formaldehyde. Detection of formaldehyde was based on H+ ion transfer reaction at the electrode–electrolyte interface facilitated with immobilized hydrogen ionophore via ion-ionophore complexation at the interface. The potentiometric enzyme biosensor demonstrated a broad linear range to formaldehyde from 0.5 to 220.0 mM (R2 = 0.9982) with fast response time within 8 s and sensitivity of 59.23 ± 0.85 mV/decade (n = 5). The operational stability of the formaldehyde biosensor with covalently immobilized alcohol oxidase showed > 95% sensitivity throughout the biosensor lifetime experimental period of 80 days. The formaldehyde biosensor based on succinimide-functionalized polyacrylate ion-selective membrane sustained negligible interference of potential interferants, e.g. methanol, ethanol, glucose and glycerol, and its feasibility for accurate assay of formaldehyde in commercial fish samples has been validated with UV–Vis spectrophotometric Nash standard method.

Histamine is one of the important biomarkers for food spoilage in the food sectors. In the present study, a rapid and simple analytical tool has been developed to detect histamine as an indirect strategy to monitor food freshness level. Optical histamine sensor with carboxyl-substituted Schiff base zinc(II) complex with hydroxypropoxy side chain deposited onto titanium dioxide nanoparticles was fabricated and was found to respond successfully to histamine. The Schiff base zinc(II) complex-histamine binding generated an enhancement of the fluorescent signal. Under the optimal reaction condition, the developed sensor can detect down to 2.53 × 10−10 M in the range of between 1.0 × 10−9 and 1.0 × 10−5 M (R2 = 0.9868). Selectivity performance of the sensor towards histamine over other amines was confirmed. The sensor also displayed good reproducibility performances with low relative standard deviation values (1.45%–4.95%). Shelf-life studies suggested that the developed sensor remains stable after 60 days in histamine detection. More importantly, the proposed sensor has been successfully applied to determine histamine in salmon fillet with good recoveries. This strategy has a promising potential in the food quality assurance sectors, especially in controlling the food safety for healthy consumption among consumers.

Objective: To study the relationship of peripheral blood TLRs and Tespa1 expression levels with cytokines and oxidative stress in patients with chronic urticaria. Methods: A total of 68 patients who were diagnosed with chronic urticaria and treated in Songzi People’s Hospital clinic between June 2014 and April 2017 were selected as the CU group of the research, and 80 healthy volunteers who received physical examination were selected as the control group. TLR2, TLR7 and Tespa1 mRNA expression in peripheral blood mononuclear cells as well as the levels of Th1/Th2 cytokines and oxidative stress indexes in serum were detected. Results: TLR2 and TLR7 mRNA expression in peripheral blood mononuclear cells of CU group were significantly higher than those of control group while Tespa1 mRNA expression was significantly lower than that of control group. Serum IFN-γ, IL-2, TNF-α, T-AOC, SOD and GSH-Px levels of CU group were significantly lower than those of control group, negatively correlated with peripheral blood TLR2 and TLR7 mRNA expression, and positively correlated with Tespa1 mRNA expression; serum IL-4, IL-5, IL-10, IL-31 and MDA levels were significantly higher than those of control group, positively correlated with peripheral blood TLR2 and TLR7 mRNA expression, and negatively correlated with Tespa1 mRNA expression. Conclusions: The changes in peripheral blood TLR2, TLR7 and Tespa1 expression in patients with chronic urticaria can cause the changes in Th1/Th2 immune response and the activation of oxidative stress.