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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.

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 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.

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.

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.

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.