A fast and ultrasensitive ELISA based on rolling circle amplification

• Published in: Analyst (London) Vol. 146; no. 9; pp. 2871 - 2877
• Main Authors: You, Minli, Peng, Ping, Xue, Zhenrui, Tong, Haoyang, He, Wanghong, Mao, Ping, Liu, Qi, Yao, Chunyan, Xu, Feng
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 07.05.2021
• Subjects: Amplification; Biomarkers; Biosensing Techniques; Colorimetry; Diagnosis; Enzyme-Linked Immunosorbent Assay; Equipment costs; Horseradish Peroxidase; Hydrogen Peroxide; Nucleic Acid Amplification Techniques; Peroxidase; Reaction time
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d1an00355k

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-H 2 O 2 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 −1 , 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. The rolling circle amplification-based ELISA shows a 10 minutes fast amplification and 50 times improvement of sensitivity.