A research group led by Prof. LIU Yong and Prof. ZHU Ling from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences developed a spatial encoding of centrifugal microfluidic disc integrated smartphone-controlled (SEDphone) platform for influenza virus subtype detection.

The research results were published in Sensors and Actuators: B. Chemical.

Influenza virus poses a serious public health threat, causing epidemics annually with high morbidity and mortality rates. Moreover, influenza viruses exhibit high mutation rates and manifest in multiple subtypes, necessitating different clinical intervention strategies. Therefore, there is an urgent need for an accurate, rapid, and portable solution to differentiate between different influenza virus subtypes, thus helping control the spread of the virus and guide clinical treatment decisions.

In this study, the researchers established a new method combining two advanced technologies, Loop-mediated Isothermal Amplification (LAMP) and CRISPR/Cas12a, to detect different types of influenza viruses in a more rapid and accurate way.

This method amplifies target sequences via LAMP and detects them through CRISPR/Cas12a-mediated trans-cleavage activity, thereby cleaving reporter probes and releasing fluorescent signals. Plus, the method is highly sensitive and can minimize false positives.

To facilitate the application of different targets, the researchers designed a versatile model that can target various flu strains. After optimization, this method can identify five types of influenza (H1N1, H3N2, H5N1, H7N9, and Influenza B) within 45 minutes, even at very low virus concentrations (10 copies/μL).

In addition, to achieve integrated operation of LAMP amplification and CRISPR detection, the researchers fabricated a centrifugal microfluidic chip with spatial encoding functionality. They also developed a portable testing device called SEDphone, which is controlled by a smartphone.

This device can amplify and detect multiple types of influenza viruses at the same time. By using a dual temperature zone design, the researchers resolved the temperature differences needed for LAMP and CRISPR/Cas12a.

Tests with clinical samples showed that this method and the SEDphone device are effective for identifying different influenza virus subtypes quickly.

"Our research offers a new way to quickly and accurately detect various pathogens in real time. This method can be used in fever clinics or at home, helping reduce the risk of unnecessary cross-infection and easing the burden on healthcare systems," said Dr. ZHU Cancan, a member of the research group.