The article presents a new developed method, which is able to detect the chicken infectious bronchitis virus (IBV) antigen in real time in various buffer solutions, using the surface plasmon resonance (PPR) nanobiosensor of the Plasmon-6 device. The PPR method is hypersensitive to changes in external factors, including the interaction of antigen (coronavirus) and specific antibodies. If the interaction does not happen, the resonance occurs at other angular parameters of the position of the sensitive PPR element relative to the laser radiation. Therefore, the PPR method is becoming a new effective rapid technique of viral pathogen detection, which is important for effective control over infectious diseases spreading. The possibility of IBK virus detection by the PPR sensor response, with preliminary immobilization of antigen or antibodies, is shown, involving the device "Plasmon- 6". The duration of the experiment is about 2 hours, which significantly saves research time compared to other methods (6-48 hours). The changes in the resonance angle in the range of 360-500 angle. sec when the IBC virus antigen binds to serum antibodies in water (distilled) were detected. The angular shift of the nanosensor resonance was determined when the IBC virus antigen bound to the serum antibodies in the PBS, which averaged 354 angular seconds. The possibilities of using the PPR method for express detection of the coronavirus infections pathogen in animal fluids in real time are demonstrated in article. Taking into account the significant social and economic negative consequences of the Coronaviridae virus family members and considering the current situation with the worldwide spread of COVID-19, the representative of the coronavirus family – the Infectious Bronchitis virus has been selected as a model.