Ultrasensitive, high-throughput, and rapid simultaneous detection of SARS-CoV-2 antigens and IgG/IgM antibodies within 10 min through an immunoassay biochip

• Published in: Mikrochimica acta (1966) 2021-08, Vol.188 (8), p.262-262, Article 262
• Main Authors: Wang, Chunhua, Wang, Chao, Qiu, Jiaoyan, Gao, Jianwei, Liu, Hong, Zhang, Yu, Han, Lin
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Antibodies; Antigen-Antibody Reactions; Antigens; Antigens, Viral - blood; Antigens, Viral - immunology; Biochips; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Coronaviruses; COVID-19; Emission; Excitation; Fluorescence; Graphene; Health aspects; Humans; IgG antibody; Immunoassay; Immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin G - immunology; Immunoglobulin M - blood; Immunoglobulin M - immunology; Microengineering; Microfluidics; Nanochemistry; Nanoparticles - chemistry; Nanotechnology; Original Paper; Particle Size; Proteins; Public health; Quantum dots; SARS-CoV-2 - immunology; SARS-CoV-2 - isolation & purification; Sensitivity and Specificity; Severe acute respiratory syndrome coronavirus 2; World health
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-021-04896-w

COVID-19 is now a severe threat to global health. Facing this pandemic, we developed a space-encoding microfluidic biochip for high-throughput, rapid, sensitive, simultaneous quantitative detection of SARS-CoV-2 antigen proteins and IgG/IgM antibodies in serum. The proposed immunoassay biochip integrates the advantages of graphene oxide quantum dots (GOQDs) and microfluidic chip and is capable of conducting multiple SARS-CoV-2 antigens or IgG/IgM antibodies of 60 serum samples simultaneously with only 2 μL sample volume of each patient. Fluorescence intensity of antigens and IgG antibody detection at emission wavelength of ~680 nm was used to quantify the target concentration at excitation wavelength of 632 nm, and emission wavelength of ~519 nm was used during the detection of IgM antibodies at excitation wavelength of 488 nm. The method developed has a large linear quantification detection regime of 5 orders of magnitude, an ultralow detection limit of ~0.3 pg/mL under optimized conditions, and less than 10-min qualitative detection time. The proposed biosensing platform will not only greatly facilitate the rapid diagnosis of COVID-19 patients, but also provide a valuable screening approach for infected patients, medical therapy, and vaccine recipients. Graphical abstract