The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P.R. China.
Department of Transfusion Medicine, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, P.R. China.
Analyst. 2021 May 7;146(9):2871-2877. doi: 10.1039/d1an00355k. Epub 2021 Apr 26.
A highly sensitive ELISA is critical for early diagnosis and biomarker discovery of various diseases. Although various ELISA technologies have been developed with high sensitivity, they are limited by poor repeatability, high cost, the dependence on complex equipment and/or a prolonged reaction time. To this end, we developed a fast and ultrasensitive ELISA (termed RELISA) based on rolling circle amplification (RCA) and enzymatic signal amplification. The RELISA is established on the traditional ELISA, with only one more RCA step that can be accomplished within 10 minutes. The prolonged single strand DNA (ssDNA) from RCA is able to enrich abundant horseradish peroxidase conjugate (HRP) modified detection probes. Consequently, the intensive HRP is able to catalyze TMB-HO to produce significantly enhanced colorimetric signals. With CEACAM-7 as a model biomarker, the RELISA achieves the limit of detection as low as 2.82 pg mL, which is ∼50 times higher than that of the traditional ELISA. Therefore, we envision that the developed RELISA would be a powerful tool for the early diagnosis of various major diseases.
一种高灵敏度的 ELISA 对于各种疾病的早期诊断和生物标志物发现至关重要。尽管已经开发出了各种具有高灵敏度的 ELISA 技术，但它们受到重复性差、成本高、对复杂设备的依赖以及/或反应时间长的限制。为此，我们开发了一种基于滚环扩增（RCA）和酶学信号放大的快速超灵敏 ELISA（称为 RELISA）。RELSIA 建立在传统 ELISA 的基础上，仅增加了一个 RCA 步骤，可在 10 分钟内完成。RCA 产生的长单链 DNA（ssDNA）能够富集大量辣根过氧化物酶标记的检测探针。因此，大量的 HRP 能够催化 TMB-HO 产生明显增强的比色信号。以 CEACAM-7 作为模型生物标志物，RELSIA 的检测限低至 2.82 pg/mL，比传统 ELISA 高约 50 倍。因此，我们设想开发的 RELISA 将成为各种重大疾病早期诊断的有力工具。
