A novel electrochemical approach to biosensing applications: Quartz tuning forks as working electrodes for immunosensors

Although cutting-edge technology has improved our understanding of many cancers, the diagnostic and treatment options available still need to be improved. Electrochemical biosensors play a key role as the most suitable platform used for this purpose. Quartz tuning forks (QTF) sensors have recently become the most valuable components for frequency measurements, with high stability, sensitivity, and low power consumption. No paper has previously been reported on the functionalization and isolation of QTF for biomarker determination using electrochemical methods, marking this research as unique for being the first to investigate the response and sensitivity of QTFs in these applications. Cardiac troponin T (cTnT), an important biomarker of cardiovascular disease, a four-step surface modification was performed to the prepared QTFs' prongs. The surface was investigated in detail utilizing cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The results showed that the QTF-based immunosensor's limit of quantitation (LOQ) was 0.81 fg/mL, and the limit of detection (LOD) was 0.24 fg/mL, with a detection range of 0.5–1500 fg/mL. The results confirmed that QTFs have unique electrode capacity in point-of-care diagnostic devices. Most importantly, due to their excellent sensitivity and low cost, QTF transducers are predicted to be widely used as a unique electrode to detect many biomarkers in EIS and CV-based electrochemical biosensors.