ABSTRACT
Before COVID-19, although the online assessment platform has developed, it is relatively slow, and people prefer to organize on-site examinations. After the outbreak of the epidemic, people realize the urgency and necessity of information construction in all walks of life. More and more researchers begin to pay attention to and explore the use of advanced machine learning methods to improve the practicability of online examinations platform. The test paper generation function is the core link, and a good test paper generation function can ensure the quality of a test paper. In this paper, an advanced unsupervised algorithm DPC(Clustering by Fast Search and Find of Density Peaks) is used to conduct deep mining and test paper generation adaptive based on the question bank and historical assessment such as assessment frequency, accuracy or score rate, and a more reasonable test paper generation function is realized. By comparing and testing the experimental results, it can be proved that the idea is correct and feasible. © 2022 Institute of Physics Publishing. All rights reserved.
ABSTRACT
COVID-19 has evolved into a global pandemic. Early and rapid detection is crucial to control of the SARS-CoV-2 transmission. While representing the gold standard for early diagnosis, nucleic acid tests for SARS-CoV-2 are often complicated and time-consuming. Serological rapid antibody tests are characterized by high rates of false-negative diagnoses, especially during early infection. Here, we developed a novel nanozyme-based chemiluminescence paper assay for rapid and sensitive detection of SARS-CoV-2 spike antigen, which integrates nanozyme and enzymatic chemiluminescence immunoassay with the lateral flow strip. The core of our paper test is a robust Co-Fe@hemin-peroxidase nanozyme that catalyzes chemiluminescence comparable with natural peroxidase HRP and thus amplifies immune reaction signal. The detection limit for recombinant spike antigen of SARS-CoV-2 was 0.1 ng/mL, with a linear range of 0.2-100 ng/mL. Moreover, the sensitivity of test for pseudovirus could reach 360 TCID50/mL, which was comparable with ELISA method. The strip recognized SARS-CoV-2 antigen specifically, and there was no cross reaction with other coronaviruses or influenza A subtypes. This testing can be completed within 16 min, much shorter compared to the usual 1-2 h required for currently used nucleic acid tests. Furthermore, signal detection is feasible using the camera of a standard smartphone. Ingredients for nanozyme synthesis are simple and readily available, considerably lowering the overall cost. In conclusion, our paper test provides a high-sensitive point-of-care testing (POCT) approach for SARS-CoV-2 antigen detection, which should greatly facilitate early screening of SARS-CoV-2 infections, and considerably lower the financial burden on national healthcare resources.