Jiangsu Sunlant Co. Ltd.

Increasing attention has been caught by the allergy-related food safety issue. The rapid and sensitive diagnosing approaches are still in high demand for providing clinical reference. Paper-based analytical devices (PADs) are appealing candidates for allergy diagnosis and prediction due to their portability, stability, and operational easiness. However, the sensitivity of PADs needs to be further improved for the targets with low abundance. In addition to the complex signal amplifications, an alternative strategy that requires fewer reagents, steps, and shorter time is anticipated. (82) RESULTS: We report fluorescent PADs (FPADs) that can accumulate and detect the major peanut allergen glycoprotein Arachis hypogaea h2 (Ara h2)-specific IgE (sIgE). The FPADs are constructed by in-situ synthesis of blue-emissive carbon dots (BCDs) on the surface of cellulose paper, followed by the conjugation of Ara h2. After the capture of sIgE, a green-emissive carbon dots-labeled secondary anti-sIgE reporter (Ab2-GCDs) is assembled on FPADs. The detection relies on the sIgE concentration-dependent color variation of FPADs. In addition, the accumulation of sIgE is achievable by filtering the sample through FPADs, improving the assay sensitivity and efficiency. It is demonstrated that the limit of detection (LOD) is 15.7 ng/mL, evidently lower than the simple immersion-based assay (90.2 ng/mL). The excellent selectivity allows sIgE quantification in serum with high accuracy. (130) SIGNIFICANCE: By harnessing the outperforming sensing performance of the proposed FPADs, the rapid, accurate, and cost-efficient diagnosis and prediction of peanut allergy can be realized. In addition, the FPADs could serve as a universal sensing platform for varying targets by flexibly engineering the capture moieties on the surface of fluorescent paper. (50).

Allergen testing has emerged as a pivotal component in prevention and treatment strategies for allergic diseases among children and the utilization of specific IgE (sIgE) through a fully automated chemiluminescent microarray immunoassay (CLMIA) has emerged as a promising trend in the simultaneous detection of multiple allergenic components of children.

The accuracy and reliability of CLMIA were verified using children's serum samples that concentrated on allergens. the allergens. The clinical diagnostic practicability of CLMIA was assessed through comprehensive evaluations including measurements of the limit of detection (LOD), intra-batch, and inter-batch precision, linearity analysis, the cross-contamination rate, and the concordance rate with the Phadia system.

After the optimization process of CLMIA, the LODs for allergens were calculated to be below 0.01 kU/L, demonstrating the high sensitivity of CLMIA. All components exhibited good linearity within the range of 0.1-100.0 kU/L and the coefficient of determinations (R² > 0.99). The data of intra-batch precision (<10 %) and inter-batch data (<15 %) illustrated the high reproducibility of CLMIA. The cross-contamination rates for allergens (<0.5 %) showed the high accuracy of CLMIA without interfering. The positive concordance rate between CLMIA and the Phadia system exceeds 90 % with a good negative concordance rate (>85 %) and the Kappa coefficients (>0.8), suggesting the close alignment of CLMIA and the Phadia system and showing the satisfactory clinical potential of CLMIA in children's allergy disease.

The application of CLMIA has been promising in allergen testing, especially for detecting multiple allergenic components in children.

Detection of specific antinuclear antibodies is very important in term of diagnosis, prognosis and management of patients with systemic autoimmune rheumatic diseases. Chemiluminescence microarray immunoassay (CLMIA) is a microdot array-based method that allows simultaneous detection of multiple antinuclear antibodies, which received increasing attention.

A CLMIA method that can detect 14 kinds of antinuclear antibodies was established and optimized. Basic performance and diagnostic performance of CLMIA was evaluated by comparing it with line immunoassay (LIA) and indirect immunofluorescence (IIF).

Through conditional exploration, the optimal blocking time and blocking temperature were determined to be 18 h and 25 °C, respectively. The enzyme-labeled secondary antibody reaction concentration was 0.1 μg/mL, the incubation temperature of serum and enzyme-labeled secondary antibody were 30 °C, and the incubation time of serum and enzyme-labeled secondary antibody were 40 min. After parameter optimization, CLMIA demonstrated high accuracy with a relative bias <15 %; high sensitivity with detection limits below 3 IU/mL for dsDNA and below 1 RU/mL for other ANAs; and high reproducibility with both intra-assay and inter-assay coefficients of variation (CV) <15 %.The CLMIA detection method established in this study was also demonstrated to have good clinical diagnostic performance, showing the highest area under curve (AUC=0.87, p=0.042 and p=0.03). The CLMIA and LIA revealed substantial to good agreements on specific antinuclear antibodies except anti-dsDNA, with the Cohen’s kappa from 0.72 to 0.89. Samples that produced discrepant results between the CLMIA and LIA methods were further analyzed. Upon additional testing, most of these samples were ultimately determined to have been correctly detected by the CLMIA assay rather than the LIA assay, suggesting that CLMIA also shows some superiority in diagnosing dsDNA.

The CLMIA could become a potential routine method for detecting ANAs with the advantages of good detection performance.