A Novel Sensitive Label-free Impedometric Electrochemical Immunosensor for Detection of t-NMP22 using FFT Square Wave Voltammetry

It is known truncated Nuclear matrix protein 22 (t-NMP22) could be used a biomarker for Bladder cancer. Therefore, in this paper a highly sensitive electrochemical technique was developed based on nanostructures modified glassy carbon (GC) electrode for detection of t-NMP22. In this measurement, immunosensor was fabricated based on the electrodeposition of gold in general the upper frequency limit is determined by the solution resistance, which depends on the specific conductivity of the electrolyte and the electrode radius. To increase the sensitivity of the electrochemical system for detection of t-NMP22, the most important parameters were optimized. The fabrication steps of the immunosensor were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. FFT square wave voltammetry (FFTSWV) was used for measurements at optimum condition. Moreover, the effect of important parameters such pH the FFTSWV parameters were investigated. The modified electrode was used for determination of different concentrations of t-NMP22; a linear range from 0.05 ng/mL to 30 ng/mL and a detection limit of 16.4 pg/mL were obtained. The proposed detection technique does not need a redox probe and was evaluated in urine, which showed good selectivity, high sensitivity and stability, reproducibility.