Surface acoustic wave biosensor-based point-of-care system for influenza diagnostics

Influenza (also called flu) is a contagious disease caused by viruses belonging to the family Orthomyxoviridae. World Health Organization (WHO) estimates that seasonal influenza is responsible for 250,000 to 500,000 deaths annually. High variability of the virus and its easy spread make influenza one of the world’s most dangerous diseases. Accurate diagnosis and prompt treatment with antiviral agents can reduce the impact of influenza. Viral culture and reverse transcriptase-polymerase chain reaction (RT-PCR) are accurate methods for identifying specific viral strains and subtypes. However, viral culture requires several days of analysis involving labour intensive and time-consuming procedures. Although RT-PCR consumes less time, this method still requires the use of equipment which is not available in outpatient clinics, but only in diagnostic or scientific laboratories. When the samples have to be sent to a laboratory to perform the test, the result will come out at least one day later which is too late for setting up an appropriate treatment. Rapid influenza diagnostic tests (RIDTs) are currently the most widely used tool for Influenza diagnosis. They are point-of-care (POC) kits which can be used without professional training. Unfortunately, these tests provide low sensitivity and often produce false negative results, especially during later stages of the disease development. Development of a POC diagnostic device to rapidly and sensitively detect the influenza virus at early stage of infection is a challenge for researchers all over the world. A team of healthcare engineering researchers from a Singapore institute of higher learning has developed a SAW biosensor-based POC system specifically for influenza viral antigen detection. By immobilising different antibodies, the biosensor platform can be modified for the detection of other disease-specific biomarkers. When multiple chips are integrated within a microfluidic channel for specimen processing and delivery, this POC system can be developed for multiplexed testing, which is simultaneous on-site detection of multiple analytes from a single specimen. This technology comprises a microfabrication process of: - Surface Acoustic Wave (SAW) biosensor chip - Surface modification protocol for antibody immobilisation - Sandwich immunoassay on microfabricated SAW biosensor chip for influenza viral protein detection - Polymer housing with microfluidic channel for bio sample delivery - Point-of-care (POC) system for SAW biosensor signal reading According to laboratory evaluation, the POC system can detect influenza viral protein with a sensitivity of 1 ng/ml. These biosensor platforms could overcome some of the challenges faced in conventional diagnosis techniques offering label-free assays with immediate results and employing small and user-friendly devices. The Singapore institute of higher learning is looking for industry collaborators who can license the technology or establish commercial agreements with technical assistance.