A novel electrochemical sensor for monitoring ovarian cancer tumor protein CA 125 on benzothiophene derivative based electrodes

COVID-19 crisis affects ovarium cancer patients seriously. Thus, it is vital to diagnose ovarium cancer, one of the most common types of cancer diagnosed and the causes of death of women around the world, at early stages. Herein, 5-(2-phenylbenzo[b]thiophen-3-yl) thiophene-2-carbaldehyde (PTTC)-based sensor is designed to detect CA-125 more precisely and rapidly via electrochemical methods. PTTC, novel benzothiophene derivative, is synthesized by electrophilic cyclization reactions and Pd-catalyst coupling reactions. Then, PTTC is dispersed homogeneously in Nafion solution, and an ink is obtained. This ink is transferred onto the glassy carbon electrode and CA-125 is incubated on this electrode. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy measurements are employed to determine sensitivity and reliability of CA-125 on PTTC based GCE electrode. The effect of CA 125 concentration, incubation time, scan rate studies are performed by CV to determine the optimum conditions. Optimum conditions are found as 3 mu L PTTC loading, 5000 ng/mL CA125 antigen concentration and 30 min incubation time. Linear range of the PTTC based GCE electrode prepared at optimum conditions are obtained by DPV as 1-100 ng/ml.Limit of detection and limit of quantification values were obtained as 0.0096 ng/mL and 0.0288 ng/mL, respectively. Interference and artificial serum results reveal that this electrode is a promising electrode for CA125 antigen determination for the ovarium cancer. PTTC is a novel and unique material for the detection of ovarium cancer antigen CA-125 and promising for CA-125 antigen detection.

Automated summary

The COVID-19 crisis has a serious impact on ovarian cancer patients, highlighting the importance of early detection. In this study, a PTTC-based sensor was designed to detect CA-125, a common marker for ovarian cancer, with higher precision and speed using electrochemical methods. The PTTC-based GCE electrode showed promising sensitivity and reliability for CA-125 detection, with optimum conditions determined as 3 μL PTTC loading, 5000 ng/mL CA125 antigen concentration, and 30 min incubation time. The linear range of this electrode was found to be 1-100 ng/mL, with a limit of detection of 0.0096 ng/mL and a limit of quantification of 0.0288 ng/mL. These findings suggest that PTTC is a novel and promising material for the detection of ovarian cancer antigen CA-125.