Micro Potentiometric Label-free Immunosensor for Glycated Hemoglobin
A miniaturized potentiometric label-free immunosensor based on the standard complementary metal-oxide-semiconduction transistor( CMOS) process and micro fabrication technique was developed to monitoring diabetes,which could detect the concentrations of glycated hemoglobin ( HbA1c) and hemoglobin. This immunosensor includes a micro field-effect transistor based sensor chip integrated with signal readout circuit and a disposable probe electrode. The micro sensor chip was designed by our lab and fabricated by Chartered Semiconductor,Singapore. The disposable probe electrode,which was integrated with sensitive electrodes array and micro reaction pool,was deposited on polyester plastic based on micro fabrication techniques. Anti-body of HbA1c and hemoglobin were immobilized on the electrode based on self assemble monolayer and gold nanoparticles. The characteristics of the electrode during modification were studied by cyclic voltammetry and electrochemical impedance technique. The response characteristic of the immunosensor was detected. HbA1c from 4 to 24 mg/L and hemoglobin from 60 to 180 mg/L can be detected by this immunosensor.