A novel AgNPs/MOF substrate-based SERS sensor for high-sensitive on-site detection of wheat gluten

Gluten,known as the major allergen in wheat,has gained increasing concerns in industrialized countries,resulting in an urgent need for accurate,high-sensitive,and on-site detection of wheat gluten in complex food systems.Herein,we proposed a silver nanoparticles(AgNPs)/metal-organic framework(MOF)substrate-based surface-enhanced Raman scattering(SERS)sensor for the high-sensitive on-site detection of wheat gluten.The detection occurred on the newly in-situ synthesized AgNPs/MOF-modified SERS substrate,providing an enhancement factor(EF)of 1.89×10^(5).Benefitting from the signal amplification function of AgNPs/MOF and the superiority of SERS,this sensor represented high sensitivity performance and a wide detection range from 1×10^(-15)mol/L to 2×10^(-6)mol/L with a detection limit of 1.16×10^(-16)mol/L,which allowed monitoring the trace of wheat gluten in complex food system without matrix interference.This reliable sandwich SERS sensor may provide a promising platform for high-sensitive,accurate,and on-site detection of allergens in the field of food safety.

Clinical and Laboratory Features, and Quality of Life Assessment in Wheat Dependent Exercise-induced Anaphylaxis Patients from Central China

Wheat dependent exercise-induced anaphylaxis（WDEIA） is a rare but potentially severe food allergy caused by the combination of wheat ingestion and physical exercise. The impact of WDEIA on quality of life（QOL） is unclear. This study characterized the clinical and laboratory features and investigated the QOL in WDEIA patients from Central China. Twenty-eight WDEIA patients were analyzed, and QOL was measured by validated Chinese version Food Allergy Quality of Life Questionnaire-Adult Form（FAQLQ-AF） and Food Allergy Independent Measure（FAIM） after obtaining the diagnosis. The results showed that half of the patients were females. The median onset age was 37 years old. The symptoms occurred within 1 h after wheat ingestion（26/28）. Symptoms of anaphylaxis included cutaneous（26/28）, respiratory（11/28）, gastro-intestinal（5/28） and cardiovascular manifestations（27/28）. Skin prick tests were positive to salt soluble（89.3%） and salt insoluble wheat allergen extracts（100%）. Positive rate to wheat, gluten and omega-5 gliadin specific Ig E was 64.3%, 92.9% and 92.9% respectively. Specific Ig E to omega-5 gliadin with a cut-off value 0.83 KU/L offered highly efficient diagnostic criterion for WDEIA（sensitivity： 89.3%; and specificity： 88.9%）. The mean scores of FAQLQ-AF and FAIM were 4.70 and 4.98 respectively and level of anti-omega-5 gliadin Ig E had positive correlations with FAQLQ scores. Thereby, WDEIA is commonly found in mid-age adults. In most cases, multi-organs especially skin and cardiovascular systems are involved. Salt insoluble wheat allergen skin test and serum specific Ig E to gluten and omega-5 gliadin help to diagnose WDEIA. QOL in WDEIA patients is severely impaired.

Non-celiac gluten sensitivity： questions still to be answered despite increasing awareness

Recently, the increasing number of patients worldwide who are sensitive to dietary gluten without evidence of celiac disease or wheat allergy has contributed to the identification of a new gluten-related syndrome defined as non-celiac gluten sensitivity. Our knowledge regarding this syndrome is still lacking, and many aspects of this syndrome remain unknown. Its pathogenesis is heterogeneous, with a recognized pivotal role for innate immunity; many other factors also contribute, inctuding tow-grade intestinal inflammation, increased intestinal barrier function and changes in the intestinal microbiota. Gluten and other wheat proteins, such as amylase trypsin inhibitors, are the primary triggers of this syndrome, but it has also been hypothesized that a diet rich in fermentable monosaccharides and polyols may elicit its functional gastrointestinal symptoms. The epidemiology of this condition is far from established; its prevalence in the general population is highly variable, ranging from 0.63% to 6%. From a clinical point of view, non-celiac gluten sensitivity is characterized by a wide array of gastrointestinal and extraintestinal symptoms that occur shortly after the ingestion of gluten and improve or disappear when gluten is withdrawn from the diet. These symptoms recur when gluten is reintroduced. Because diagnostic biomarkers have not yet been identified, a double-blind placebo-controlled gluten challenge is currently the diagnostic method with the highest accuracy. Future research is needed to generate more knowledge regarding non-celiac gluten sensitivity, a condition that has global acceptance but has only a few certainties and many unresolved issues.