For Detecting Ultra-Low Concentrations of Carcinoembryonic Antigen (CEA) using Microwaves

- Published in the scientific journal Biosensors and Bioelectronics (JCR ranking: 97.6%, Q1, IF: 12.6) -

- Successfully developed a biosensor for detecting ultra-low concentrations of carcinoembryonic antigen (CEA) -

A research team led by Professor Kim Nam-Young from the Department of Electronic Engineering at Kwangwoon University, in collaboration with Professor You Xiao from Qingdao University (a Ph.D. graduate of Kwangwoon University's Department of Electronic Engineering), successfully developed a biosensor for detecting ultra-low concentrations of carcinoembryonic antigen (CEA).

This study highlights that the early diagnosis and screening of tumor markers are essential for effective cancer treatment, as well as for improving the efficiency and prognosis of treatments for tumor recurrence and metastasis. A circuit based on an interdigitated split-ring resonator (IDTSRR) was developed and applied to a microwave biosensor, combined with machine learning, to detect ultra-low concentrations of carcinoembryonic antigen (CEA). CEA was detected using a microwave sensor operating at a resonant frequency of 4.33 GHz, and it was found that the sensor generated new frequencies in the range of 1？2 GHz when exposed to CEA analytes. The position and intensity of the newly generated frequencies can be used to characterize and predict the concentration of the CEA solution.

The proposed sensor demonstrates excellent resonant linearity (R2 = 0.999) for various concentrations of CEA, with an extremely low detection limit (39 pg/mL) and high sensitivity (27.5 MHz/(ng/mL)). A machine learning approach was implemented to predict the CEA concentration in blood samples, and the results were found to closely match the concentrations detected by the sensor. Western blot was used to compare the CEA content in four cell types, and the biosensor was utilized for validation. The results of both experiments demonstrated a good level of agreement. This is the first case of verifying the reliability of a biosensor at the cellular level. The proposed concept demonstrates excellent detection performance for convenient and rapid tumor marker detection. Therefore, it holds significant value as a supplementary diagnostic method for cancer.

  [Photo description: Overview of the CEA concentration detection system]

 [Photo description: Sensor fabrication process and CEA molecular structure. (a) Overview of sensor preparation using photolithography and chemical etching, (b) Molecular formula and 3D model representation of CEA, (c) Electric field simulation of the pure sensor, (d) Electric field simulation of the sensor with a solution, (e) SEM characterization analysis after solution deposition, (f) Partial amplification after solution deposition

This research was published in the internationally renowned journal Biosensors and Bioelectronics (IF: 12.6; JCR ranking: 97.6%) by Elsevier, under the title "Detection of carcinoembryonic antigen specificity using microwave biosensor with machine learning." (https://doi.org/10.1016/j.bios.2024.116908)