Abstract: Provided are an electrochemical gas sensor and a fabrication method therefor. A sensing electrode, a reference electrode and an auxiliary electrode in a planar arrangement are arranged on an upper layer in a sensor housing, and an electrolyte and a membrane material are arranged on a lower layer in the sensor housing. An upper part of the sensor housing is provided with a vent, and a lower part of the sensor housing is provided with a connector for connecting three electrodes and connected to an external circuit. Compared with the traditional cylindrical stacked electrochemical gas sensor, the fabrication method for a plate-body thin-film type sensor is simple, is less affected by the change of ambient pressure, temperature and humidity, and is beneficial to the flattening and miniaturization of electronic instruments and apparatus for gas analysis.

Abstract: A lipid delivery system, a virus-like structure (VLS) vaccine constructed therefrom, and a lipid particle capable of encapsulating an mRNA molecule encoding a SARS-CoV-2-specific antigen are provided. After the lipid particle encapsulates an mRNA molecule encoding a SARS-CoV-2 antigen, a SARS-CoV-2 S1 antigen protein can be embedded on a surface of an envelope structure of the lipid under specific buffer conditions to produce a VLS vaccine with an antigen-encoding mRNA molecule encapsulated inside and an outer membrane presenting a required viral antigen protein. The vaccine has a superior specific antibody-inducing ability to a SARS-CoV-2 mRNA vaccine and a polypeptide vaccine, can maintain a long-lasting high antibody level, and can also exhibit excellent immune binding abilities for the emerging different variants.