The severe acute respiratory syndrome originated by the new coronavirus (SARS-CoV-2) that emerged in late 2019, known to be a highly transmissible and pathogenic disease, has caused the COVID-19 global pandemic outbreak. Thus, diagnostic devices that help epidemiological public safety measures to reduce undetected cases and isolation of infected patients, in addition to significantly help to control the population’s immune response to vaccine, are required. To address the negative issues of clinical research, we developed a Diagnostic on a Chip platform based on a disposable electrochemical biosensor containing laser-induced graphene and a protein (SARS-CoV-2 specific antigen) for the detection of SARS-CoV-2 antibodies. The biosensors were produced via direct laser writing using a CO₂ infrared laser cutting machine on commercial polyimide sheets. The presence of specific antibodies reacting with the protein and the K₃[Fe(CN)₆] redox indicator produced characteristic and concentration-dependent electrochemical signals, with mean current values of 9.6757 and 8.1812 µA for reactive and non-reactive samples, respectively, proving the effectiveness of testing in clinical samples of serum from patients. Thus, the platform is being expanded to be measured in a portable microcontrolled potentiostat to be applied as a fast and reliable monitoring and mapping tool, aiming to assess the vaccinal immune response of the population.

PMMA:MXene passivates a perovskite/ETL interface boosting performance and stability. Less interfacial defects increase the charge lifetime resulting in a higher density of photo-generated carriers.

Nb₂O₅–Ti₃C₂ exhibits beneficial band-edge alignment, favoring carrier migration with a higher density of extracted charges and increased electron lifetime.