Sensitivity Enhancement of Electrochemical Biosensor for Point of Care (POC) Applications: Vi Antigen Detection as a Case Study

A novel approach for signal enhancement of electrochemical biosensors by incorporating mechanical vibrations has been developed. We report the electrochemical study of the ferricyanide and ferrocyanide Fe CN 6 − 3 − 4 a redox couple, at room temperature (∼25 °C), under the effect of mechanical vibrations of different frequencies applied to the sensor, for sensitivity enhancement. The experimental results showed a sensitivity enhancement of ∼332% (from 3.125 nA M − 1 to 13.5 nA M − 1 ) at 88.75 Hz of vibration. This novel approach of signal sensitivity enhancement is also validated with antibody immobilization-based Vi antigen detection for typhoid assessment. The sensitivity enhancement up to ∼15% is achieved for Vi antigen detection under the mechanical vibration of 120 Hz. The sensor is fabricated using microfabrication technology. The vibration-assisted ultrasensitive biosensing platform is also prototyped as a portable and Internet of Thing (IoT) enabled device, suitable for point-of-care applications. Detailed features of the prototype along with the test results are elaborated in the paper.