Simultaneous detection of fungal (1,3)‐β‐D‐glucan and procalcitonin using a dual‐label time‐resolved fluorescence immunoassay

Neonatal infectious diseases are a serious threat to the health of newborns. The aim was to establish a new detection method for the simultaneous measurement of (1,3)-beta-D-glucan and procalcitonin in serum for the early screening and efficacy testing of neonatal infectious diseases. We established a sandwich dual-label time-resolved fluorescence immunoassay (TRFIA): anti-(1,3)-beta-D-glucan/procalcitonin antibodies immobilized on 96-well plates captured (1,3)-beta-D-glucan/procalcitonin antigens and then banded together with the detection antibodies labeled with europium(III) (Eu(3+) )/samarium(III) (Sm(3+) ) chelates. Finally, time-resolved fluorometry (TRF) was used to measure the fluorescence intensity. The linear correlation coefficient (R(2) ) of the (1,3)-beta-D-glucan standard curve was 0.9913, and the R(2) of the procalcitonin standard curve was 0.9911. The detection sensitivity for (1,3)-beta-D-glucan was 0.4 pg/mL (dynamic range: 0.6-90 pg/mL), and the average recovery was 101.55%. The detection sensitivity for procalcitonin was 0.02 ng/mL (dynamic range: 0.05-95 ng/mL), and the average recovery was 104.61%. There was a high R(2) between the present TRFIA method and a commercially available assay (R(2) = 0.9829 for (1,3)-beta-D-glucan and R(2) = 0.9704 for procalcitonin). Additionally, the cutoff values for (1,3)-beta-D-glucan and procalcitonin were 23.95 pg/mL and 0.055 ng/mL, respectively. The present TRFIA method has high sensitivity, accuracy, and specificity and is an effective method for early screening and efficient testing of neonatal invasive fungal infection. This article is protected by copyright. All rights reserved.