Functionalised silicon microchannel immunosensor with portable electronic readout for bacteria detection in blood

This paper reports the development of functionalized silicon microchannel immunosensor with optimized electrode geometry and portable electronic interface towards specific detection of E.coli in blood samples for the first time. The sensor with simple electrode geometry fabricated by low cost screen printing method detects 10³CFU/ml E.coli in spiked blood samples in 30 minutes without any labeling and with less than 3% false positive results which is of great clinical significance. To avoid biofouling, an initial centrifugation is done for the first 15 minutes of the total 30 mins which helps in improving specificity. The battery operated portable electronic circuit is designed with zero offset features to take into account the variability in the sensor fabrication for faithful display of bacteria concentration range. Hence, in comparison to the existing reports, the proposed immunosensor system has an optimum combination of the essential features required for a commercial biosensor.