Ultra-Precise Label-Free Nanosensor Based on Integrated Graphene with Au Nanostars Toward Direct Detection of IgG Antibodies of SARS-CoV-2 in Blood

Alireza Hashemi, Seyyed; Bahrani, Sonia; Mojtaba Mousavi, Seyyed; Omidifar, Navid; Ghaleh Golab Behbahan, Nader; Arjmand, Mohammad; Ramakrishna, Seeram; Bagheri Lankarani, Kamran; Moghadami, Mohsen; Shokripour, Mansoureh; Firoozsani, Mohammad; Chiang, Wei-Hung

Rapid distribution of airborne contagious pathogenic viruses such as SRAS-CoV-2 and their severely adverse impacts on different aspects of the human society, along with significant weaknesses of traditional diagnostic platforms, raised the global requirement for the design/fabrication of precise, sensitive, and rapid nanosystems capable of specific detection of viral illnesses with almost negligible false-negative results. To address this indispensable requirement, we have developed an ultra-precise fast diagnostic platform capable of detecting the trace of monoclonal IgG antibody against S1 protein of SARS-CoV-2 within infected patients' blood specimens with COVID-19 in about 1 min. The as-developed electrochemical-based nanosensor consists of a highly activated graphene-based platform in conjunction with Au nanostars, which can detect SARS-CoV-2 antibodies with a fantastic detection limit (DL) and sensitivity of 0.18×10-19 % V/V and 2.14 μA.%V/V. cm-2, respectively, in human blood plasma specimens even upon the presence of a high amount of interfering compound/antibodies. The nanosensor also exhibited remarkable sensitivity/specificity compared with the gold standard (i.e., ELISA assay), which furtherly confirmed its superb performance.